question

ch1

answer

...

question

fast anterograde

answer

NTs, membranous organelles/vescicles/200-400mmday, neurotubule-DEPENDENT, mediated by kinesin

question

fast retrograde

answer

NGF, neurotropic viruses, toxins, mediate by dynein

question

5 most common brain tumors

answer

GEMMS: glioblastoma-multiforme, ependymoma, medullablastioma, meningioma, schwannoma (benign)

question

most fatal tumor

answer

glioblastoma-multiforme

question

Most common

answer

glioblastoma-multiforme

question

Most common NON- metastasize

answer

Meningioma: noninvasive, tumor of falx and convexity of hemisphere

question

Medulloblastoma

answer

2nd most common posterior fossa tumor in children; may metastasize through CSF tracts.

question

brain tumors in adults (most --least common)

answer

glioblastoma-multiforme, astrocytoma, meningioma

question

brain tumors in children (most--least common)

answer

astrocytoma, medullablastoma, ependymoma

question

In ventricles; 60% of brain tumors in spinal cord

answer

ependymoma

question

glial cells

answer

non neuronal in nervous system: macro + micro glial, schwann, ependymal, tanycytes

question

macro glial

answer

astrocytes + oligodendrocytes/CNS

question

micro glial

answer

phagocytes/CNS

question

schwann

answer

PNS

question

ependymal

answer

in ventricles, choroid plexus, make CSF

question

tanycytes

answer

involved in transport of ventricles and neuropil, project to hypothalamic nu--regulate gonadotropic hormone

question

blood brain barrier

answer

tight jxns; infarcts destroy jxns-->vasogenic edema

question

blood csf barrier

answer

tight jxns; permeable to insulin and prealbumin

question

pigments/inclusions

answer

neuronal/nuclear: hirano bodies lewy bodies, cowdry type A inclusion bodies; cytoplasmic: neurofibrillary tangles, melanin/neuromelanin, negri bodies, lipofuscin granules

question

hirano

answer

intraneuronal, rodlike, hippocampus, alzheimer

question

Neurofibrillary tangles

answer

intracytoplasmic, degenerated neurofilaments, Alzheimer

question

lewy bodies

answer

neuronal, Parkinson + (Alzheimer?)

question

melanin/neuromelanin

answer

intracytoplasmic, loss of melanin in Parkinson

question

cowdry type A inclusion bodies

answer

intranuclear, herpes simplex encephalitis

question

negri bodies

answer

intracytoplasmic, rabies, in pyramidal and purkinje cells

question

lipofuscin granules

answer

cytoplasmic, aging, from lysozymes

question

free nerve endings receptors

answer

pain, thermo, above dermis basement membrane

question

merkel disks/uncapsulated

answer

light touch, above dermis basement membrane

question

encapsulated

answer

Meissener corpuscles/touch & 2PT discrimination, Pacinian corpuscle/vibration, below dermis basement membrane

question

schwannoma case

answer

unilateralsensorineural hearing loss -lesion in CN8 (cerebellopontine); CN8 more common> CN5 or CN7

question

ch2

answer

...

question

brainstem and spinal cord, ALAR PLATE

answer

lateral, sensory

question

brainstem and spinal cord, BASAL PLATE

answer

medial, motor (memory tip: "Buffy/Basal Motor")

question

ALPHA-FETOPROTEIN/AFP

answer

in amniotic fluid and maternal serum. High: spina bifida, anencephaly; low: down syndrome

question

neurocrest orgin

answer

PNS, skeletal and connective tissue components of pharyngeal arches, pigment cells, odontoblasts, aorticopulmonary septum of heart, parafollicular cells, chromaffin cells, and other nervous system cells

question

modalities from lateral(sensory) to medial(motor)

answer

SSA, GSA, SVA, GVA- (sulcus limitans)- GVE, SVE, GSE //before limitans: Special before General, S before V; opposite after limitans: General before Special, V before S

question

hindbrain/3rd primary vesicle

answer

METencephalon before MYELencephalon

question

five secondary vesicles

answer

become adult derivatives (walls - cavities)

question

telencephalon

answer

cerebral hemisphere - lateral ventricles

question

diencephalon

answer

thalamus - 3rd ventricle

question

mesencephalon

answer

midbrain - cerebral aqueduct

question

metencephalon

answer

pons & cerebellum - upper part of 4th ventricle

question

myelencephalon

answer

medulla - lower part of 4th ventricle

question

anterior neuropore

answer

closure form lamina terminalis; failure--anencephaly

question

posterior neuropore

answer

failure--spina bifida (occulta, meningocele-only subarachnoid exposed, miningomyelocele-spinal cord exposed, rachischisis-complete fissure)

question

myelination begins at 4th month gestation

answer

corticospinal tract myelination completes by 2nd year postnatal; cerebral association cortex contt into 3rd decade; oligodendrocytes NOT in retina

question

conus medullaris ends

answer

L3 newborn, L1 adult

question

optic nerve and chiasma is similar to thalamus how?

answer

derived from diencephalon; optic fibers occupy choroid fissure; failure--coloboma iridis

question

anterior pituitary

answer

adenohypophysis; rathke's pouch derived; associated with congenital cystic tumor: craniopharyngioma

question

posterior pituitary

answer

neurohypophysis; neuroectoerm derived

question

1:1K, results from elongation and herniation of cerebellar tonsils through foramen magnum, blocking cerebrospinal fluid flow

answer

arnold-chiari malform type 2

question

1:25K, result from riboflavin inhibitors, posterior fossa trauma or viral infx; dilaton of 4th ventricle from failure of foramina Luschka and Magendie to open

answer

dandy-walker malform

question

1:1K, due to stenosis of cerebral aqueduct, excess CSF in ventricles and subarachnoid space; from maternal infx (cytomegalovirus and toxoplasmosis)

answer

hydrocephalus

question

mental retardation, microcephaly and congenital heart dz; holoprosencephaly most severe

answer

Fetal alcohol syndrome

question

failure of midline cleavage of forebrain--telencephalon has singular cavity; in trisomy 13/patau; corpus callosum may absent

answer

holoprosencephaly

question

from bilateral hemispheric infarction secondary to occlusion of carotid arteries. Hemispheres are replaced by hugely dilated ventricles

answer

hydraencephaly

question

tufts of hair in lumbosacral, clubfoot, UMN signs (legs don't seem to work right)

answer

spina bifida case

question

ch3

answer

...

question

T1 MRI

answer

Bone is black in T1 and T2 mri; this help differentiate an mri from CT; in T1, the outside white is actually fats.

question

T1-nerve cells/gray matter=gray (hypointense); white matter=white (hyperintense)

answer

...

question

T2

answer

"negative" opposite of T1; fibers are black, cells are gray /lighter; fluid is white

question

optic chiasm is above or below pituitary?

answer

above pituitary

question

ch4

answer

...

question

location of dural venous sinuses

answer

btw periosteal and meningeal layers of dura mater

question

subarachnoid space terminates at..

answer

level of second sacral vertebra; contains CSF

question

subdural space

answer

traversed by bridging veins in cranium

question

laceration of superior cerbral/bridging veins that drains to superior sagital sinus (that traverse btw dura and arachnoid)

answer

subdural hematoma

question

epidural space

answer

cranial: contains meningeal arteries and veins; spinal: contains fatty areolar tissue, lymphatics and venous plexuses--site of anesthetic injection "paravertebral/saddle nerve block

question

laceration of middle meningeal artery from maxillary artery (btw periosteal and meningeal layers of dura matter)

answer

epidural hematoma

question

inflammation of pia-arachnoid area of brain, spinal cord or both. Kernig (knee flex pain) sign, fever, headache, nuchal rigidity; cause cranial nerve palsies and hydrocephalus. CSF findings: PMN leukocytes, dec glucose, inc protein

answer

Bacterial meningitis

question

asceptic meningitis; fever, headache, nuchal rigidity, Kernig sign; CSF findings: lymphocytes, normal glucose, inc protein

answer

viral meningitis

question

interventricular foramina (of Monro)

answer

communication btw two lateral ventricles and 3rd ventricle

question

cerebral aqueduct (of Sylvius)

answer

blockage of duct btw 3rd and 4th ventricle cause noncommunicating hydrocephalus (excess CSF in 3rd ventricles)

question

3 outlets: two lateral formaina (of Luschka) and one median foramen (of Magendie)

answer

communication btw subarachnoid space and 4th ventricle

question

communicating hydrocephalus

answer

result from blockage w/in subarachnoid space (e.g. adhesions after meningitis)

question

normal-pressure hydrocephaus

answer

CSF not absorbed by arachnoid villi; may occur secondary to posttraumatic meningeal hemorrhage; progressive dementia, ataxic gait, urinary incontinence (wacky, wobbly, and wet)

question

hydrocephalus ex vacuo

answer

loss of cells in caudate nu (e.g. Huntington's)

question

pseudotumor cerbri

answer

benign intracranial hypertension; results from inc resistance to CSF outflow at arachnoid villi; obese,women,papilledema w/o mass,elevated CSF pressure,deteriorating vision

question

CSF

answer

formed by choroid plexus, absorption through arachnoid villi into superior sagittal sinus--into circulation; presence of RBC (trauma or ruptured berry aneurysm)

question

transtentorial/uncal herniation

answer

protrusion of brain through tentorial incisure; result in oculomotor paresis and contra hemiplegia

question

transforaminal/tonsilar herniation

answer

protrusion of brain stem and cerebellum through foramen magnum; obtundation and death

question

subfalcine/cingulate herniation

answer

below falx cerebri (vertical falx) headache, compression of ant. cerebral artery may result in contra leg weakness.

question

subdural hematoma case

answer

common after acute deceleration injury/fall or auto accident, rarely skull fracture. Fell 4 wks ago, history of progressive weakness on R side, hemiparesis, reflex asymmetry

question

ch. 5

answer

...

question

anterior spinal artery/ASA

answer

supplies blood for (5): 1. spinal cord and lower brainstem; 2. 2/3 of spinal cord, 3. medulla--pyramid, 4. medial lemniscus, and 5. root fibers of CN XII

question

Medial Medulla//Medial medullary syndrome

answer

Effects: 1. pyramidal tract, 2. medial lemniscus, 3. hypoglossal nucleus. Produced by block of 1. PARAMEDIAN br. of VERTEBRAL and/or 2. anterior spinal arteries. Yields: 1. contralateral paresis , 2. deviation of the tongue to side of lesion, and, 3. usually loss of fine touch and vibratory sense on the contralateral side.

question

internal carotid system—3 branches before splitting into MCA and ACA

answer

1. Ophthalmic artery, 2. Posterior communicating artery, 3. Anterior choroidal artery

question

ophthalmic artery

answer

enters orbit with CN II, central artery of retina is a branch, occlusion=blindness

question

posterior communicating artery

answer

Supplies: 1. hypothalamus and 2. ventral thalamus; aneurysm here is 2nd most common aneurysm of circle of willis; CNIII palsy

question

anterior choroidal artery

answer

from internal carotid artery; perfuses: 1. lateral geniculate body, 2. globus pallidus, and 3. poterior limb of internal capsule

question

anterior cerebral artery/ACA

answer

supplies medial surface of hemisphere from frontal pole to parietoocipial sulcus; irrigates paracentral lobule (has leg-foot area of motor and sensory cortices)

question

anterior communicating artery

answer

MOST common site of aneurysm of circle of willis; cause bitemporal lower quadrantanopia

question

medial striate arteries

answer

penetrating arteries of ACA; supply: 1. anterior portion of putamen and 2. caudate nu and 3. anteroinferior part of internal capsule

question

middle cerebral artery

answer

Supplies: 1. lateral convexity of hemisphere (Broca's, Wernicke's) 2. face and arm areas of motor and sensory cortices, 3. frontal eye field

question

lateral striate arteries

answer

penetrating branches of MCA; arteries of stroke, supply: 1. internal capsule, 2. caudate nu, 3. putamen, 4. globus pallidus.

question

vertebral artery

answer

br. of subclavian, gives rise to: 1. anterior spinal artery, 2. posterior inferior cerebellar artery (PICA-supplies dorsolateral quadrant of medulla; this quadrant includes nu ambiguus /CN IX, X, XI, and inferior surface of cerebellum.)

question

Lateral Medulla//Wallenberg's syndrome

answer

Effects: 1. inf. cerebellar peduncle, 2. vestibular nu,3. trigeminal nu., 4. anterolateral system, 5. nu. ambiguus, 6. nu. solitarius, 7. descending sympathetic fibers. Produced by block of PICA (or vertebral a.) Yields: 1. ataxia, 2. nystasmus, 3. weakness of limbs , 4. pain/temperature loss, 5. Horner's syndrome, 6. decreased taste hoarseness, 7. dysphagia on same side as lesion, 8. loss of pain/temperature on CONTRA body.

question

basilar artery

answer

formed by two vertebral arteries; gives rise to: 1. PARAMEDIAN br. of pontine arteries, 2. labyrinthine artery, 3. anterior inferior cerebellar artery (AICA), 4. superior cerebellar artery, 5. posterior cerebral artery (PCA)

question

Medial Pontine Basis-Tegmentum//Foville's syndrome

answer

Effects: 1. corticospinal, 2. corticobulbar trs, 3. facial colliculus, 4. abducens nu, 5. medial lemniscus. Produced by block of PARAMEDIAN br. of BASILAR artery, ventral and dorsal territories. Yields paresis of the contra. body, and inability to abduct the ipsi. eye; may yield 'wrong-way eyes', i.e., inability to direct gaze to the side of the lesion. Due to damage to: both the 1. abducens nu. and 2. internuclear neurons projecting thru MLF to opposite III nucleus. ARAS damage also likely.

question

PARAMEDIAN br. of pontine arteries//from basilar

answer

supply base of pons (CORTICOSPINAL fibers and exiting root fibers of ABDUCENS)

question

AICA/anterior inferior cerebellar artery

answer

Supplies: 1. caudal lateral pontine tegmentum (CN VII), 2. spinal trigeminal tract of CN V and 3. inferior surface of cerebellum

question

Lateral Caudal Pons//AICA syndrome

answer

Effects: 1. middle cerebellar peduncle, 2. vestibular nu, trigeminal nu., 3. anterolateral system, 4. descending sympathetic fibers. Produced by block of AICA. yields ataxia, vertigo, nystagmus, pain-temperature loss on ipsilateral face, loss of pain-temperature sense to contralateral body, Horner's syndrome, possibly ipsilateral hearing loss.

question

labyrinthine artery

answer

in 15% of people from basilar, 85% from anterior inferior cerebellar artery (AICA)

question

superior cerebellar artery

answer

1. dorsolateral tegmentum of rostral pons (i.e. rostral to motor nuc of CN V), 2. superior cerebellar peduncle, 3. superior surface of cerebellum and cerebellar nu, and 4. cochlear nu

question

posterior cerebral artery/PCA

answer

Supplies: 1. midbrain, also 2. thalamus, 3. lateral and medial geniculate bodies and 4. occipital lobe (incl. visual cortex and inferior surface of temporal lobe, incl hippocampal formation); blockage results in contra hemianopia with macular sparing

question

vision problems and horrible headache (acute), clumsiness and can't read half the printed page of newspaper, history of hypertension and diabetes mellitus; complete hemianopia, contra face and limb sensory loss, CT presence of ischemic infarction w/ hemorrhagic change.

answer

posterior cerebral artery/PCA infarct case

question

Midbrain Basis//Weber's syndrome

answer

effects oculomotor nerve or fascicles produced by block of branches of PCA and/or top of the basilar artery. 3rd nerve palsy, pupil dilation (defect of Edinger Westphal//GVE PARASYMP pregang to ciliary ganglion ), poss. Hemiparesis

question

Midbrain Basis+Tegmentum//Benedikt's syndrome

answer

Effects: 1. oculomotor nerve, 2. red nucleus, and 3. sup cerebellar penduncle, 4. subs nigra. Produced by block of branches of PCA and top of the basilar artery. Yielding an ipsilateral CNIII palsy, contralateral ataxia and intention tremor, contralateral paresis of body, 'central 7' for contralateral face (corticobulbars).

question

two sources of internal capsule blood supply

answer

anterior choroidal of internal carotid + lateral striate arteries of MCA

question

2 veins of brain

answer

superior cerebral "bridging" veins (drains to superior sagital sinus) and great cerebral vein of Galen (drains deep cerebral veins into straight sinus)

question

ch6

answer

...

question

gray rami communicans

answer

unmyelinated postgang symp fibers; all levels of spinal cord

question

white rami communicans

answer

myelinated SYMP pregang fibers; T1-L3 (extent of lateral horn and IMLCC)

question

ciliospinal center of Budge

answer

C8-T2, mediates symp innervation of eye

question

intermediolateral nu cell column of lateral horn

answer

c8-L3, mediates entire SYMP of body

question

nu dorsalis of Clark

answer

c8-L3, gives rise to dorsal spinocerebellar tract

question

sacral parasymp nuc

answer

s2-4

question

nu of accessory nerve

answer

c1-6

question

phrenic nu

answer

c3-6

question

cauda equina

answer

motor and sensory root in subarachnoid space below conus medullaris; exit vertebral canal through lumbar intervertebral and sacral foramina

question

myotatic reflex

answer

monosynaptic ipsi muscle stretch reflex/MSR; interuption:areflexia; afferent is Ia fiber.

question

lower back pain radiated down to foot x 2mo; absent R. ankle jerk, weakness of dorsiflex and plantar flex, dec pinprick over dorsum of foot; compression of first sacral nerve foot on L at level of L5-S1 vertebrae

answer

lumbar intervertebral disc herniation case

question

ch7

answer

ANS

question

autonomic output control

answer

by hypothalamus

question

absence of ganglion cells in myenteric plexus, neural crest cells did not migrate into colon; dilation and hypertophy of colon with fecal retention

answer

megacolon/hirschsprung's disease/congenital aganglionic megacolon

question

jewish, auto-recessive, abnormal sweating, unstable bp, orthostatic hypotension, difficulty in feeding, progressive sensory loss, loss of neurons in autonomic and sensory ganglia

answer

familial dysautonomia/riley day syndrome

question

painful, disorder of terminal arteries of extremities; idiopathic paroxysmal bilateral cyanosis of digits, Tx: preganglionic sympathectomy

answer

raynaud's dz

question

excessive parasymp tone

answer

peptic ulcer dz

question

horner's syndrome

answer

oculosympathetic paralysis

question

shy-drager syndrome

answer

SYMP pregang neurons from IMLCC problem; orthostatic hypotension, anhidrosis, impotence, and bladder atonicity

question

ACh release problems

answer

botulism, myasthenic syndrome

question

ch8

answer

tracts of spinal cord

question

ascending tracts

answer

1. posterior/dorsal column (gracile, cuneate)—2pt discrimination, vibration, 2. dorsal spinocerebellar tract, 3. ventral spinocerebellar tract, 4. anterlateral system//lateral spinothalamic tract//pain temp--sensory 5. ventral spinothalamic tract—crude touch, 6. Trigeminothalamic//CN V, VII, IX, X (ventral—FACE pain/temp & dorsal—FACE tactile discrimination and pressure)

question

descending tracts

answer

1. lateral corticospinal tract, 2. hypothalamospinal tract, 3. rubrospinal tract, 4. reticulospinal 5. vestibulospinal tract, 6. ventral corticospinal tract

question

The spinothalamic tract (LATERAL & VENTRAL)// ascending tracts

answer

is a sensory pathway originating in the spinal cord. It transmits information to the thalamus about pain, temperature, itch and crude touch. The pathway decussates at the level of the spinal cord, rather than in the brainstem like the posterior column-medial lemniscus pathway and corticospinal tract. The cell bodies of neurons that make up the spinothalamic tract are located in the spinal ganglia. These neurons receive input from sensory fibers that innervate the skin and internal organs.

question

TRIGEMINOTHALAMIC TRACT (Anterior/ventral & dorsal )// ascending tracts

answer

pain, temperature, and crude touch pathway from the face, head and neck. It receives input from trigeminal nerve, facial nerve, glossopharyngeal nerve and vagus nerve (these are primary sensory neurons—1st order neurons).

question

TRIGEMINOTHALAMIC TRACT//1st order neurons

answer

Input from trigeminal nerve, facial nerve, glossopharyngeal nerve and vagus nerve (these are primary sensory neurons—1st order neurons). After entering the pons the central projections of the first order neurons descend to the medulla, forming the spinal trigeminal tract and synapse in the spinal trigeminal complex.

question

TRIGEMINOTHALAMIC TRACT//2nd order neurons

answer

Axons of the second order neurons cross the midline and terminate in the ventral posterior medial thalamus//VPM (as opposed to the ventral posterior lateral thalamus as in the dorsal column/medial leminscus and spinothalamic tract pathway) to mediate conscious sensation of pain and temperature from the face, head and neck.

question

TRIGEMINOTHALAMIC TRACT//3rd order neurons

answer

The third order neuron in the thalamus then connects to the sensory cortex of the postcentral gyrus. The affective/motivational information is mediated by connections to reticular formation, midbrain, and the midline nuclei of the thalamus. The midline nuclei third order neurons then synapse to the cingulate and insular cortex.

question

posterior/dorsal column--medial lemniscus pathway// ascending tracts

answer

tactile discrimination, vibration sensation, form recognition, jt and muscle sensation/conscious proprioception

question

posterior/dorsal column--medial lemniscus pathway RECEPTORS

answer

pacinian and meissner's tactile corpuscles, joint receptors, muscle spindles, golgi tendon organs

question

posterior/dorsal column--medial lemniscus pathway 1ST NEURON

answer

in spinal/dorsal root ganglia all levels, project axon to MEDIAL root of entry zone of spinal cord; gives rise to gracile fasciculus/lower extremities, cuneate/upper, collaterals for spinal reflexes/myotatic, axons ascend in dorsal columns and terminate in gracile and cuneate nu of caudal MEDULLA

question

posterior/dorsal column--medial lemniscus pathway 2ND NEURON

answer

in gracile and cuneate nu of caudal medulla; gives rise to axons and internal arcuate fibers that decussate and form bundle/medial lemniscus; medial lemniscus ascends through contra brain stem and terminates in VPL nu of thalamus.

question

posterior/dorsal column--medial lemniscus pathway 3RD NEURON

answer

in VPL nu of thalamus, project through posterior limb of internal capsule to postcentral gyrus (primary somatosensory cortex/brodmann's 3,1,2)

question

posterior/dorsal column--medial lemniscus pathway TRANSECTION

answer

above sensory decussation: contra loss of posterior/dorsal column modalities; in the spinal cord: ipsi loss of post/dorsal column modalities

question

lateral spinothalamic tract/Anterolateral system // ascending tracts

answer

pain and temp sensation

question

lateral spinothalamic tract/Anterolateral system - RECEPTORS

answer

free nerve endings, receives from fast and slow conducting pain fibers A-d and C, respectively

question

lateral spinothalamic tract/Anterolateral system- 1ST NEURON

answer

in spinal/dorsal root ganglia all levels, project axons to spinal cord through dorsolateral tract of Lissauer/LATERAL root entry zone to 2nd neuron

question

lateral spinothalamic tract/Anterolateral system - 2ND NEURON

answer

in dorsal horn; give rise to axons that decussate in ventral white commissure and ascend contra lateral funiculus, axons terminate in VPL nu of thalamus

question

lateral spinothalamic tract/Anterolateral system - 3RD NEURON

answer

in VPL nu of thalamus, project through posterior limb of internal capsule to postcentral gyrus (primary somatosensory cortex/brodmann's 3,1,2)

question

lateral spinothalamic tract/Anterolateral system - TRANSECTION

answer

contra loss of pain and temp BELOW lesion

question

lateral corticospinal tract //descending tract

answer

voluntary skilled motor activity, primarily upper limbs, not fully myelinated until end of second year //babinski's sign till then

question

lateral corticospinal tract course

answer

arises from layer V of cerebral cortex from 3 cortical areas in equal aliquots:Brodman 6, 4, 3-1-2; 85% decussate at medulla pyramids; terminates contra (through interneurons) on ventral horn motor neurons

question

lateral corticospinal tract transection

answer

above decussation: contra spastic paresis and babinski's sign; in spinal cord: ipsilataral spastic paresis and babinski sign

question

hypothalamospinal tract (Oculosympathetic pathway)//descending

answer

from hypothalamus to ipsi ciliospinal center of IMLCC at T1-2-->pregang symp here to superior cervical ganglion-->postgang symp here projects through tympanic cavity, cavernous sinus, superior orbital fissure to dilator muscle of iris; interruption: horner's syndrome/ipsi

question

pain on left side of chest and PROGRESSIVE weakness of left lower limb x2mo; weakness in left lower limb, spasticity and (progressive) hyperreflexia at knee and ankle, L side loss of 2pt discrimination, vibratory sense and proprioception below hip, loss of pain and temp sensation below T7 dermatome on right side; UMN lesion at T5-6, incomplete spinal cord lesion, hemisection of spinal cord, ipsi hemiplegia with contra pain and temperature deficits due to decussating fibers of spinothalamic tract

answer

spinal cord hemisection/brown sequard syndrome

question

ch9

answer

lesions of spinal cord

question

by transection of corticospinal tract or destruction of cortical cells of origin: spastic paresis, pyramidal signs/Babinski

answer

UMN lesions

question

by damage to motor neurons: flaccid paralysis, areflexia, atrophy, fasciculations, fibrillations . Poliomyelitis or Werdnig-Hoffmann disease

answer

LMN lesions

question

amyotrophic lateral sclerosis/ALS, Lou Gehrig; damage to corticospinal tracts, pyramidal signs, damage to LMNs with LMN symptoms, NO sensory deficits.

answer

combined UMN and LMN

question

example: dorsal column disease/tabes dorsalis, has neurosyphilis, loss of tactile discrimination and position and vibration sensation, irritative involvement of dorsal root-->pain and paresthesias, Romberg sign/dorsal column ataxia

answer

SENSORY pathway lesions

question

combined SENSORY and MOTOR:

answer

...

question

damage to: 1. dorsal columns (fasciculi gracile/leg and cuneate/arm)--ipsi loss of tactile discrimination and position and vibration sensation; 2. lateral corticospinal tract: ipsi spastic paresis, pyramidal signs below lesion; 3. lateral spinothalamic tract: contra loss of pain and temperature one segment below lesion; 4. hypothalamospinal tract at T1 and above: ipsi Horner's syndrome (miosis, ptosis, hemianhidrosis, enophthalmos); 5. ventral/anterior horn: ipsi flaccid paralysis of innervated muscles.

answer

spinal cord hemisection/brown sequard syndrome

question

COMPLETE SPINAL CORD SECTION

answer

Similar to hemisection (?) + will have bladder control problem (parasymp: CN 3,7,9, 10 and S2,3,4)

question

ventral spinal artery occlusion

answer

causes infarction of anterior 2/3 spinal cord spares dorsal columns and horns; results in damage to: 1. lateral cortiocspinal tracts--bilateral spastic paresis with pyramidal signs below lesion, 2. lateral spinothalamic tracts--bilateral loss of pain and temperature sensation below lesion, 3. hypothalamospinal tract at T2 and above--bilateral Horner's syndrome, 4. ventral/anterior horns (LMNs): bilateral flaccid paralysis of innervated muscles, 5. corticospinal tracts to sacral parasymp centers at S2-4--bilateral damage and loss of voluntary bladder and bowel control

question

caused by pernicious/megaloblastic anemia, damage to: 1. dorsal columns/gracile and cuneate--bilateral loss of tactile discrimination and position and vibration sensation, 2. lateral corticospinal tracts--bilateral spastic paresis with pyramidal signs, 3. spinocerebellar tracts--bilateral arm and leg dystaxia

answer

subacute combined degeneration/B12—COBALAMIN neuropathy

question

central cavitation of cervical cord, damage to: 1. ventral white commissure--damage decussating lateral spinothalamic axons--bilateral loss of pain and temp. 2. ventral horns--LMN lesions--flaccid paralysis of intrinsic muscles of hands

answer

syringomyelia

question

same spinal cord pathology and symptoms as subacute combined degeneration

answer

friedreich's ataxia

question

plaques involve white matter of cervical segments of spinal cord; random and asymmetric

answer

multiple sclerosis

question

PNS lesions

answer

Guillian Barre syndrome/acute idiopathic polyneuritis/post infectious polyneuritis; affects motor fibers of ventral roots and peripheral nerves, LMN symptoms

question

Guillain-Barre syndrome

answer

demyelination and edema, upper cervical root/C4 and respiratory paralysis, caudal cranial nerve with facial diplegia 50% cases, elevated protein causes papilledema, sensory fibers affected--paresthesias, protein in CSF elevated but without pleocytosis/albuminocytologic dissociation.

question

intervertebral disk herniation

answer

L4 or 5 to S1 interspace 90% cases; C5-6 or C6-7 10% cases//prolapse of nucleus pulposus through defective anulus fibrosus and into vertebral canal; nucleus pulposus impinges on spinal roots--spinal root symptoms (paresthesias pain, sensory loss, hyporeflexia and muscle weakness)

question

cauda equina syndrome/spinal roots L3 to C0

answer

nerve root tumor/ependymoma or dermoid tumor or lipoma of terminal cord// severe radicular unilateral pain, sensory distribution in unilateral saddle-shaped area, unilateral muscle atrophy and absent quadriceps (L3) and ankle jerks (S1), unremarkable incontinence and sexual fxns, gradual and unilateral onset.

question

conus medullaris syndrome/S3 to C0

answer

intramedullary tumor/ependymoma; pain, bilateral, sensory distribution in bilateral saddle-shaped area, unremarkable muscle changes, normal quadriceps and ankle reflexes, severely impaired incontinence and sexual fxns. Sudden and bilateral onset.

question

ch10

answer

brain stem

question

medulla medial structures

answer

1. hypoglossal nu of CN XII, 2. medial lemniscus (crossed fibers from gracile and cuneate nu), 3. pyramid (corticospinal fibers)

question

medulla lateral structures

answer

1. nu ambiguus (CN IX, X, XI), 2. vestibular nu (CN VIII), 3. inferior cerebellar peduncle (dorsal spinocerebellar, cuneocerebellar and olivocerebellar tracts), 4. lateral spinothalamic tract (spinal lemniscus), 5. spinal nu and tract of trigeminal nerve

question

pons

answer

has dorsal tegmentum and ventral base

question

rostral midbrain

answer

dorsal tectum, intermediate tegmentum, base; aqueduct lies btw tectum and tegmentum

question

corticonuclear/corticobulbar fibers

answer

project bilaterally to all motor cranial nerve nuclei except facial nucleus. Upper face: bilateral corticonuclear input, lower face only contra corticonuclear input.

question

ch 11

answer

cranial nerves

question

olfactory/CN I

answer

SVA, unmyelinated axons of biopolar neurons, enters cavity through cribiform plate of ethmoid bone; 1st-olfactory receptor cells, 2nd-mitral cells of olfactory bulb/principal cells, excitatory,Glutaminergic, project through olfactory tract and lateral olfactory stria to primary olfactory cortex/Brodmann 34 and amygdale

question

olfactory pathway lesions

answer

from olfactory groove meningiomas--ipsi anosmia; lesions of parahippocampal uncus--olfactory hallucinations

question

: ipsi ANOSMIA, ipsi optic atrophy, contra papilledema; anterior fossa meningioma

answer

foster kennedy syndrome

question

optic nerve/CN II

answer

SSA, tract of diencephalon, nonregenerable

question

oculomotor nerve/CN III

answer

GSE: moves eyes; GVE : constricts pupil, accommodates, converges; exits brain stem from interpeduncular fossa of midbrain, passes cavernous sinus, enters orbit through superior orbital fissure

question

muscles innv. by CN III

answer

GSE: medial, superior, inferior rectus, inferior oblique and levator palpebrae (upper eyelid); GVE: pregang parasymp--edinger westphal nu to ciliary ganglion of orbit, ciliary ganglion postgang para to sphincter pupillae/miosis and ciliary muscle/accommodation

question

oculomotor paralysis/palsy

answer

from transtentorial herniation (tumor, subdural or epidural hematoma); denervation of levator palpebrae--ptosis; denervation of extraocular muscles--diplopia when look in direction of paretic muscle, eye down and out (unopposed action of lateral rectus/CN6 and superior oblique/CN 4); interruption of pre parasymp innv./internal ophthalmoplegia--dilated, fixed pupil and paralysis of accommodation/cycloplegia;

question

other CN III impairment

answer

Example 1. transtentorial/uncal herniation— inc supratentorial pressure compression/stretching oculomotor nerve (1. sphincter pupillae fibers affected--dilated, fixed pupil; 2. somatic efferent fibers affected--external strabismus/exotropia); Example 2. aneurysms of carotid and posterior communicating arteries compress CN III within cavernous sinus or interpeduncular cistern—affect peripheral pupilloconstrictor fibers (uncal herniation); Example 3. diabetes mellitus/diabetic oculomotor palsy--oculomotor nerve, damages central fibers and spares sphincter pupillae fibers

question

CN IV/Trochlear

answer

GSE, pure motor, superior oblique--depresses, intorts, abducts eye; arises from contra trochlear nu of caudal midbrain, decussates beneath superior medullary velum of midbrain and exits brain stem DORSAL surface-caudal to inferior colliculus, encircles midbrain enters orbit through superior orbital fissure

question

CN IV paralysis

answer

extorsion of eye and weakness of downward gaze, vertical diplopia when looking down, head tilting to compensate for extorsion

question

CN V/trigeminal

answer

SVE: from motor nuc of trigeminal nerve in lateral midpontine tegmentum, innv. muscles of mastication; GSA: provides sensory innv to face, mucous membranes of nasal and oral cavities and frontal sinus, hard plate, deep structures of head, innv. dura of ant. and middle cranial fossae/supratentorial dura

question

lesions of CN V

answer

loss of general sensation/hemianesthesia from face and mucous membranes of oral and nasal cavities; loss of corneal reflex/afferent limb, CN V-1; flaccid paralysis of muslces of mastication; deviation of jaw to weak side (unopposed opposite lateral pterygoid muscle); paralysis of tensor tympani--hypoacusis/partial deafness to low-pitched sounds; trigeminal neuralgia/tic douloureux--recurrent paroxysms of sharp stabbing pain in branch(es) of the nerve.

question

CN VI/abducens

answer

GSE: lateral rectus-abducts eyes; nu in dorsomedial tegmentum of caudal pons; exiting intraaxial fibers pass through coriticospinal tract; lesion--alternating abducent hemiparesis

question

CN VI paralysis

answer

most common results from long periopheral course of nerve, meingitis, subarachnoid hemorrhage, late-stage syphilis, trauma; convergent medial strabismus esotropia-inability to abduct; horizontal diplopia with max separation of double images when look toward paretic lateral rectus

question

CN VII/facial

answer

pharyngeal arch 2; GSA, GVA, SVA, GVE, SVE: SVE --muscles of facial expression, SVA--taste, GVE: salivation, lacrimation, (GSA or GVA?): general sensation from external ear

question

CN VII SVA component/taste

answer

cell in geniculate ganglion, projects to solitary tract and nu-->VPM of thalamus-->gustatory cortex of parietal lobe/parietal operculum; innv taste buds from ant. 2/3 tongue through (intermediate nerve, chorda tympani, lingual nerve (CN V-3), central gustatory pathway.

question

CN VII GVE parasymp

answer

lacrimal, submandibular, sublingual glands; pregang parasymp in superior salivatory nu of caudal pons; lacrimal pathway: superior salivatory nu projects through intermediate and greater petrosal n. to pterygopalatine ganglion-->lacrimal gland of orbit; submandibular pathway: superor salivatory nu projects through intermediate n and chorda tympani to submandibular ganglion-->submandibular and sublingual glands

question

CN VII SVE

answer

facial nu, loops around abducent nu of caudal pons, exits brain stem in cerebellopontine angle, enters internal auditory meatus, traverses facial canal, br. To stapedius m of middle ear, exits skull through stylomastoid formaen, innv. muscles of facial expression and stylohyoid m., posterior belly of digastric m and stapedius m.

question

CN VII lesions

answer

1. flaccid paralysis of muslces of facial expression/upper + lower face, 2. loss of corneal reflex/efferent orbicularis m --corneal ulceration, 3. loss of taste, 4. hyperacusis/increased acuity to sounds due to stapedius paralysis, 5. Bell's palsy/peripheral facial paralysis-by trauma or infx/upper and lower face, 6. crocodile tears syndrome/lacrimation during eating--aberant regeneration of SVE fibers, 7. supranuclear/central facial palsy-contra weakness of lower face, sparing of upper, 8. bilateral facial nerve palsies-Guillain-Barre syndrome, 9. Mobius' syndrome-congenital facial diplegia/CN VII and convergent strabismus/CN VI

question

CN VIII/vestibulocochlear

answer

SSA; vetibular n.-maintains equilibrium and balance, cochlear n-mediates hearing; exits brain stem at cerebellopontine angle and enters internal auditory meatus; confined to temporal bone

question

vestibular n.

answer

assoc. w/ cerebellum/flocculonodular lobe and ocular motor nu; regulates compensatory eye movt.; 1st order sensory bipolar neurons in vestibular ganglion in fundus of internal auditory meatus; projects peripheral processses to hair cells of cristae of semicircular ducts and hair cells of utricle and saccule, projects central processes to 4 vestibular nu of brain stem and flocculonodular lobe of cerebellum, conducts efferent fibers to hair cells from brain stem; lesion--disequilibrium, vertigo, nystagmus.

question

cochlear n.

answer

1st order sensory bipolar neurons in spiral/cochlear ganglion of modiolus of cochlear, w/in temporal bone, projects peripheral processes to hair cells of organ of Corti, projects central processes to dorsal and ventral cochlear nu of brain stem conducts efferent fibers to hair cells from brain stem; lesions: hearing loss/sensorineural deafness, tinnitus; acoustic neuroma/schwannoma of cochlear n. causes deafness

question

CN IX/glossopharyngeal

answer

GSA, GVA, SVA, SVE (stylopharyngues ), GVE (parasymp, parotid gland); sensory, with CN X, XI, XII mediates taste, salivation, and swallowing; mediates input from carotid sinus--has baroreceptors for arterial blood pressure, mediates input from carotid body--has chemoreceptors for CO2 and O2 of blood; pharyngeal arch 3

question

CN IX lesion

answer

loss of gag/pharyngeal reflex/interruption of afferent limb, hypersensitive carotid sinus reflex/syncope, loss of general sensation in pharyns, tonsils, fauces, back of tongue, loss of taste from posteror 1/3 tongue, glossopharyngeal neuralgia--severe stabbing pain in root of tongue

question

CN X/vagal

answer

pharyngeal arch 4 and 6; GSA, GVA, SVA, SVE, GVE; mediates phonation, swallowing, elevation of palate, taste, and cutaneous sensation from ear; innv. viscera of neck, thorax and abdomen;

question

CN X lesions

answer

1. ipsi paralysis of soft palate, pharynx, larynx-leads to dysphonia/hoarseness, dyspnea, dysarthria, dysphagia; 2. loss of gag/palatal reflex (efferent); 3. anesthesia of pharynx and larynx leads to unilateral loss of cough reflex; 4. aortic aneurysms or tumors of neck + thorax compress vagal nerve lead to cough, dyspnea, dysphagia, hoarseness, chest/back pain; 5. complete laryngeal paralysis-fatal if it is bilateral/asphyxia; 6. parasympathetic "vegetative" disturbances: bradycardia (irritative lesion), tachycardia (destructive lesion), dilation of stomach; 7. oculocardiac reflex-pressure on eye slows heart rate/afferent of CN V-1 and efferent of CN X; 8. carotid sinus reflex-pressure on carotid sinus slows heart rate/bradycardia (efferent of CN X)

question

CN XI/accessory/spinal accessory

answer

SVE; mediates head and shoulder movt and innv. laryngeal m.; has cranial and spinal division

question

CN XI cranial division/accessory portion

answer

from nu ambiguus of medulla, exits medullar from postolivary sulcus and joins vagal n; innv. intrinsic m. of larynx through inferior/recurrent laryngeal n. except cricothyroiid m.

question

CN XI spinal division/spinal portion

answer

from ventral horn of cervical segments C1-6; roots exit spinal cord laterally btw ventral and dorsal spinal roots; innv. sternocleidomastoid m. and trapexius m.

question

CN XI lesions

answer

paralysis of sternocleidomastoid m-difficulty in turning head to contra side; paralysis of trapezius m-shoulder droop and inability to shrug shoulder; paralysis and anesthesia of larynx if cranial root is involved

question

CN XII/hypoglossal

answer

GSE; tongue movt; arises from hypoglossal nu of medulla, exits medulla in preolivary sulcus; innv. intrinsic and extrinsic m. of tongue; extrinsic m. are genioglossus, styloglossus, and hyoglossus.

question

CN XII lesion

answer

transection--hemiparalysis of tongue; protrusion causes tongue to point toward lesioned/weak side (unopposed opposite genioglossus m);

question

ch 12

answer

trigeminal system

question

trigeminal system

answer

sensory innv to face oral cavity and supratentorial dura through general somatic afferent GSA, also innv muslces of mastication through special visceral efferent SVE (CN V-3)

question

trigeminothalamic pathways

answer

1. ventral trigeminothalamic tract: pain temp from face and oral cavity (1st neuron/trigeminal ganglion-->spinal tract of trigeminal nerve and synapse on neuron in spinal nu of trigeminal nerve-->decussating axons that terminate in contra VPM nu-->through posterior limb of internal capsule to face area of somatosensory cortex/Brodmann 3,1,2) 2. dorsal trigeminothalamic tract: tactile discrimination and pressure sensation from face and oral cavity, receives from Meissner's and Pacinian (1st neuron in trigeminal ganglion synapse in principal sensory nu-->neuron here projects to VPM-->VPM projects through posterior limb internal capsule to face area somatosensory Broadmann 3,1,2)

question

trigeminal reflexes

answer

1. corneal/consensual disynaptic reflex; 2. jaw jerk reflex monosynaptic myotatic reflex//hyperreflexia indicates UMN lesion; 3. tearing/lacrimal reflex--result of corneal or conjunctival irritation; 4. oculocardiac reflex--pressure on globe results in bradycaria

question

trigeminal lesions

answer

Trigeminal neuralgia/tic douloureux; Tx--carbamazepine

question

cavernous sinus

answer

has internal carotid artery, CN III, IV, V-1,2, VI, postgang symp fibers to orbit

question

Ch13

answer

auditory system

question

auditory system/exteroceptive special somatic afferent system

answer

detect 20-20KHz ; derived from otic vesicle (from otic placode - a thickening of surface ectoderm)

question

bipolar cells of spiral/cochlear ganglion

answer

project to hair cells of organ of Corti; nerve to nuclei

question

cochlear nuclei

answer

(at jxn of medulla and pons), receive input from cochlear nerve; project contra to superior olivary nu and lateral lemniscus

question

superior olivary nu

answer

sound localization, receives bilateral input from cochlear nuclei; projects to lateral lemniscus

question

trapezoid body

answer

in pons; contains decussating fibers from ventral cochlear nu

question

lateral lemniscus

answer

receives from contra cochlear nu and superior olivary nu

question

nu of inferior colliculus

answer

receives from lateral lemniscus; projects through brachium of inferior colliculus to medial geniculate

question

medial geniculate body

answer

receives from nu of inferior colliculus; projects through internal capsule as auditory radiation to primary auditory cortex, transverse temporal gyri of Heschl of superior temporal gyrus (cortex)

question

transverse temporal gyri of Heschl

answer

contain primary auditory cortex/Brodmann's 41, 42; gyri in depths of lateral sulcus

question

Weber's test

answer

fork at vertex of skull; normal: hears equally on both sides; unilateral conduction deafness hears vibration more loudly in affected ear; unilateral partial nerve deafness hears vibration more loudly in normal ear.

question

Rinne test

answer

compares air and bone conduction; fork on mastoid process until vibration is no longer heard; then fork in front of ear. Normal--hears vibration in air after bone conduction is gone; positive Rinne test: sound conduction is normal, i.e. AC > BC

question

brain stem auditory evoked potentials/BAEPS

answer

clicks present to each ear; scalp electrodes and computer generate a series of 7 waves associated with specific areas of auditory pathway

question

ch 14

answer

vestibular system

question

vestibular system

answer

derived from otic vesicle (from otic placode), maintains posture and equilibrium and coordinates head and eye movt.

question

kinetic labyrinth/3 semicircular ducts

answer

respond to angular acceleration and deceleration of head, hair cells respond to endolymph flow

question

static labyrinth/utricle + saccule

answer

respond to position of head with respect to linear acceleration, pull of gravity

question

vestibular ganglion

answer

in fundus of internal auditory meatus; bipolar neurons in this ganglion project to hair cell, project their central processes as vestibular nerve/CN VIII to vestibular nu and flocculonodulare lobe of cerebellum

question

vestibular reflexes

answer

vestibular/horizontal nystagmus, postrotatory/horizontal nystagmus, caloric nystagmus/stimulationof horizontal ducts

question

vestibular horizontal nystagmus

answer

fast phase in direction of rotation; slow phase in opposite direction//FSSO (fast same direction; slow opposite direction)

question

postrotatory

answer

opposite that of vestibular horizontal nystagms: fast phase in opposite direction of rotation; slow phase in direction of rotation; patient past-points and falls in direction of previous rotation

question

caloric nystagmus

answer

normal: COWS; eyes deviate to the opposite side of cold water injection

question

caloric nystagmus in UNCONSCIOUS PATIENTS

answer

brainstem intact: deviation of eyes to side of COLD irrigation; bilateral MLF transaction: deviation of abducting eye to side of cold irrigation; lower brain stem damage to vestibular nu: no deviation of eyes

question

ch 15

answer

visual system

question

ganglion cells of retina

answer

axons of these cells form optic nerve/CN II, contra nasal hemiretina and ipsi temporal hemiretina project to one lateral geniculate body.

question

optic nerve

answer

projects through optic canal and cross at optic chiasm; transection BEFORE optic chiasm causes ipsi blindness, loss direct pupillary light reflex (consensual reflex intact b/c efferent constriction is by CNIII pre gangciliary post ganglion); transection of ipsi temporal +nasal hemiretina tract + contra nasal (inferior portion) hemiretina --> ipsi blindness and contra upper temporal quadrant visual field defect/junction scotoma //can't see left visual field and right upper temporal quadrant

question

optic chiasm

answer

central of chiasm: decussating fibers from two nasal hemiretinas, lateral of chiasm: noncrossing fibers from two temporal hemiretinas; projects fibers to suprachiasmatic nu of hypothalamus; midsagittal transection/pressure (from pituitary tumor)-->bitemporal visual fields hemianopia ; bilateral lateral compression -->binasal visual fields hemianopia

question

optic tract

answer

fibers from ipsi temporal + contra nasal hemiretina-->projects to: ipsi lateral geniculate body (allow you to see L or R visual field), pretectal nu, superior colliculus; transection causes contra hemianopia (cut left tract can't see right temporal + left nasal visual field=can't see things from the right hemifield/right field)

question

lateral geniculate body

answer

receives input from: 1. layer VI of striate cortex/Brodmann 17, 2. ipsi temporal hemiretina and contra nasal hemiretina ((body is 6 Layered nu; 1,4,6 receive contra/crossed; 2,3,5 receive ipsi/noncrossed)); projects through geniculocalcarine tract to layer IV of primary visual cortex/Brodmann 17

question

geniculocalcarine tract/visual radiation

answer

projects through two divisions to visual cortex: upper & lower division/Meyer's loop

question

upper division of visual radiation

answer

projects to upper bank of calcarine sulcus/CUNEUS; input from superior retinal quadrants/inferior visual field quadrants; transection--contra lower quadrantanopia; lesions of both cunei--lower altitudinal hemianopia

question

lower division of visual radiation

answer

course anteriorly then posteriorly to end in lower bank of calcarine sulcus/LINGUAL GYRUS; input from inferior retinal quadrants/superior visual field quadrants; transection--contra upper quadrantanopia/pie in the sky; transection of both lingual gyri causes upper altitudinal hemianopia

question

visual cortex/brodmann 17

answer

on banks (upper=cunei; lower=lingual gyrus) of calcarine fissure; lesions cause contra hemianopia w/macular sparing; posterior area--macular input/central vision, intermediate area--paramacular input/peripheral input, anterior area--monocular input

question

lesion of left Meyer's loop/visual radiation to inferior bank of calcarine sulcus

answer

results in upper right homonymous quadrantanopia/right pie in the sky; can't see top right quadrant; Homonymous hemianopsia, or homonymous hemianopia occurs when there is hemianopic visual field loss on the same side of both eyes-->total loss of L or R field

question

pupillary light reflex

answer

ganglion cells of retina project axon to pretectal nuclei in midbrain-->pretectal nu projects through posterior commissure crossed and uncrossed fibers to accessory oculomotor/edinger-westphal-->edinger-westphal nu gives rise to pregang parasymp fibers exit midbrain with CN III and synapse with postgang parasym neurons of ciliary ganglion-->ganglion gives rise to postgang parasymp that innv sphincter muscle of iris-->constrict pupil with light stimulus enter optic nerve.

question

optic nerve lesion and pupillary light reflex

answer

LOSS direct pupillary light reflex/ RESULT in dilation (consensual reflex intact--bc pupillary light pathway goes through pretectal nucleus to communicate to contra CN III nu Edinger Westphal-->ciliary ganglion-->sphincter pupillae-->pupil constriction);

question

pupillary dilation pathway

answer

symp; interruption will cause--Horner's syndrome

question

hypothalamic neurons of paraventricular nu

answer

project to ciliospinal center T1-2 of IMLCC of spinal cord

question

ciliospinal center of Budge T1-2

answer

projects pregnag symp through symp trunk to superior cervical ganglion

question

superior cervical ganglion

answer

projects postgang symp through perivascular plexus of carotid system to dilator muslce of iris. Postganglionic sympathetic fibers pass through tympanic cavity and carernous sinus and enter orbit through superior orbital fissure

question

near reflex and accommodation

answer

...

question

cortical visual pathway

answer

from primary visual brodmann 17 to visual assoication cortex brodmann 19

question

visual association cortex/brodmann 19

answer

project through corticotectal tract to superior colliculus and pretectal nu

question

superior colliculus and pretectal nu

answer

project to oculomotor complex of midbrain (rostral accessory/edinger westphal-pupillary constriction through ganglion; caudal accessory/edinger westphal-contraction of ciliary muscle, inc refractive power of lens; medial rectus subnucleus of CN III-convergence)

question

frontal eye field

answer

in posterior part of middle frontal gyrus/brodmann 8; regulates VOLUNTARYsaccadic eye movt; stimulation/irritation causes contra deviation of eyes/away from lesion; destruction causes transient ipsi conjugate deviation of eyes/toward lesion.

question

occipital eye fields

answer

in brodmann 18 + 19 of occipital lobes; cortical centers for INVOLUNTARY smooth pursuit tracking; stimulation causes contra conjugate deviation of eyes

question

subcortical center for lateral conjugate gaze

answer

in abducent nu of pons; receives from contra frontal eye field; projects to: 1. ipsi lateral rectus m. and 2. through medial longitudinal fasciculus/MLF to contra medial rectus subnucleus of oculomotor complex

question

subcortical center for vertical conjugate gaze

answer

in midbrain at level of posterior commissure; rostral interstitial nu of MLF, associated with Parinaud's syndrome

question

MLF syndrome/internuclear ophthalmoplegia

answer

damage/demyelination to MLF btw abducent and oculomotor nu; causes (contra) medial rectus palsy on attempted lateral conjugate gaze and monocular horizontal nystagmus in abducting eye; convergence is normal; common in multiple sclerosis

question

one and a half syndrome

answer

bilateral lesions of MLF and unilateral lesion of abducent nu; only lateral rectus fxn during lateral conjugate gaze.

question

argyll robertson pupil

answer

pupillary light-near dissociation; absence of miotic rxn to light (both direct and consensual), preservation of miotic rxn to near stimulus/accommodation-convergence; syphilis and diabetes

question

horner's syndrome

answer

transection of oculosymp pathway at any level; miosis, ptosis, apparent enophthalmos and hemianhidrosis

question

relative afferent/marcus gun pupil

answer

from lesion of optic nerve (afferent limb); eye unaffected can cause affected eye to contrict??

question

transtentorial

answer

uncal herniation; result of inc supratentorial pressure (brain tumor or hematoma); pressure cone forces parahippocampus uncus through tentorial incisure-->forces contra crus cerebri against tentorial edge/Kernohan's notch and puts pressure on ipsi CN III and posterior cerebral artery: 1. ipsi hemiparesis (pressure on corticospinal tract in contra crus cerebri); 2. fixed and dilated pupil, ptosis, and down and out eye (pressure on ipsi oculomotor n.); 3. contra homonymous hemianopia (compression of posterior cerebral artery which supplies visual cortex)

question

papilledema/choked disk

answer

noninflammatory congestion of optic disk from inc ICP, caused by brain tumors, subdural hematoma or hydrocephalus; does not alter visual acuity, but cause bilateral enlarged blind spots; asymmetric and greater on side of supratentorial lesion.

question

ch16

answer

lesions of brain stem

question

lesions of medulla

answer

...

question

medial medullary syndrome

answer

ASA syndrome; corticospinal tract--contra babinsky, contra spastic hemiparesis, contra medial lemniscus--contra loss of tactile vibration from trunk and extremities, hypoglossal nu or intraaxial root fibers/CN XII--ipsi flaccid hemiparalysis of tongue//tongue protrude to side of lesion/weak side

question

lateral medullary/wallenberge; dissociated sensory loss

answer

PICA syndrome; affected structures: 1. vestibular nu--nystagmus, nausea, vomitting, vertigo; 2. inferior cerebellar peduncle--ipsi cerebellar signs (dystaxia, dysmetria/past pointing, dysdiadochokinesia); 3. nu ambiguus of CN IX, X, XI--ipsi laryngeal, pharyngeal, palatal hemiparalysis/loss of gag reflex/efferent limb, dysarthria, dysphagia, dysphonia/hoarseness; 4. glossopharyngeal nerve roots--loss of gag reflex/afferent limb; 5. vagal nerve roots--same as nu. ambiguus lesion; 6. spinothalamic tracts/spinal lemniscus--contra loss of pain and temerature sensation from trunk and extremities; 7. spinal trigeminal nu and tract--ipsi loss of pain and temp of face; 8. descending sympathetic tract--ipsi Horner's syndrome

question

lesions of pons

answer

(next 6)

question

1. medial inferior pontine syndrome

answer

occlusion of PARAMEDIAN branches of basilar artery: corticospinal tract--contra spastic hemiparesis, medial lemniscus--contra loss of tactile sensationo trunk + extremities, abducent nerve roots--ipsi lateral rectus paralysis

question

2. lateral inferior pontine syndrome

answer

AICA syndrome; 1. FACIAL nu and intraaxial n. fibers--ipsi facial n. paralysis, ipsi loss of taste from ant. 2/3, ipsi loss of lacrimation and reduced salivation, loss of corneal dn stapedial reflexes/efferent limb 2. COCHLEAR nu and intraaxial n. fibers--unilateral central deafness 3. VESTIBULAR nu and intraaxial n. fibers--nystagmus, nausea, vomiting and vertigo 4. spinal nu and tract of TRIGEMINAL nerve.--ipsi loss of pain and temp from face 5. middle and inferior CEREBELLAR peduncles--ipsi limb and gait dystaxia 6. ANTEROLATERAL system/spinothalamic tracts/spinal lemniscus--contra loss of pain and temp from trunk and extremities 7. descending SYMPATHETIC tract--ipsi Horner's syndrome

question

3. medial longitudinal fasciculus/MLF syndrome/internuclear ophthalmoplegia

answer

interrupts fibers from contra abducent nu that project through MLF to ipsi medial rectus subnucleus of CN III; medial rectus palsy on attempted lateral conjugate gaze and nystagmus in abducting eye; convergence ok; multiple sclerosis

question

4. facial colliculus syndrome

answer

pontine glioma or vascular accident; internal genu of CN VII and nu of CN VI under facial colliculus

question

5. (pons) lesions of internal genu of facial nerve

answer

cause ipsi facial paralysis, ipsi loss of corneal reflex

question

6. (pons) lesions of abducent nu

answer

cause lateral rectus paralysis, medial convergent strabismus, horizontal diplopia

question

lesions of midbrain

answer

next 3

question

dorsal midbrain/parinaud syndrome

answer

pinealoma or germinoma of pineal region; 1.superior colliculus and pretectal area--paralysis of upward and downward gaze, pupillary disturbances, absence of convergence 2. cerebral aqueduct--noncommunicating hydrocephalus

question

paramedian midbrain/benedikt syndrome

answer

affected: 1. oculomotor n. roots/intraaxial fibers--complete ipsi oculomotor paralysis, eye abduction and depression by intact lateral rectus/CN VI and superior oblique/CN IV, ptosis (levator palpebrae superioris) and fixation and dilation of ipsi pupil (complete internal ophthalmoplegia) 2. dentatothalamic fibers--contra cerebellar dystaxia with intention tremor 3. medial lemniscus--contra loss of tactile sensation from trunk + extremities

question

medial midbrain/weber's syndrome

answer

affected: 1. oculomotor n. roots/intraaxial fibers--complete ipsi oculomotor paralysis, eye abduction and depression by intact lateral rectus/CN VI and superior oblique/CN IV, ptosis (levator palpebrae superioris) and fixation and dilation of ipsi pupil 2. corticospinal tracts--contra spastic hemiparesis 3. corticonuclear fibers--contra weakness of lower face/CN VII, tongue to weak side/CN XII, palate/CN X, upper face spared, uvula and pharyngeal wall are pulled toward normal side/CN X

question

acoustic neuroma/schwannoma

answer

benign intracranial tumor, affected: 1. vestibulocochlear n/CN VIII--tinnitus and unilateral nerve deafness; 2. vestibular nerve of CN VIII--vertigo, nystagmus, nausea, vomitting, unsteadiness of gait; 3. facial n/CN VII--facial weakness and loss of corneal reflex/efferent limb; 4. spinal tract of trigeminal n/CN V--paresthesia, anesthesia of ipsi face and loss of corneal reflex/afferent limb; 5. neurofibromatosis type 2 (bilateral acoustic neuromas)

question

jugular foramen syndrome

answer

glomus jugulare tumor, inner ear tumor, compression of CN IX, X, XI; affected: 1. glossopharyngeal n/IX--ipsi gag reflex, ipsi loss of pain, temp, taste in tongue 2. vagal n/CN X--ipsi paralysis of soft palate and larynx, ipsi loss of gag reflex 3. accessory n/XI--paralsysi of sternocleidomastoid (inability to turn head opposite side), paralysisof trapezius (shoulder droop, inability to shrug shoulder)

question

locked-in syndrome

answer

lesion of base of pons (infarction, trauma, tumor, demyelination); corticospinal and corticonuclear tracts affected bilaterally; oculomotor and trochlear nerves not injured; conscious and may communicate through vertical eye movt.

question

central pontine myelinolysis

answer

lesion of base of pons affects corticospinal and corticobulbar tracts; assoc. w/ alcohlism or rapid correction of hyponatremia; spastic quadriparesis, pseudobulbar palsy, mental changes; may become "locked-in"

question

"top of the basilar" syndrome

answer

embolic occlusion of rostral basilar artery, optic ataxia and psychic paralysis of fixation of gaze/Balint's syndrome, ectopic pupils, somnolence, cortical blindness, w/ or w/o visual anosognosia/Anton's syndrome

question

subclavian steal syndrome

answer

thrombosis of L. subclavian artery prox to vertebral artery; blood shunted retrograde down L vertebral artery into L subclavian artery; transient weakness and claudication (pain cause by little blood flow) of left arm on exercise and vertebrobasilar insufficiency/vertigo,dizziness

question

cerebellopontine angle

answer

jxn of medulla, pons, cerebelllum; CN VII and VIII; five brain tumors and one cyst (SAMEE):Schwannoma, arachnoid cyst, meningioma, ependymoma, epidermoid

question

ch17: thalamus

answer

division of diencephalon-integrates sensory and motor systems

question

anterior nucleus

answer

hypothalamic input from mamillary nu through mamillothalamic tract; projects to cingulate gyrus and part of Papez circuit of emotion of limbic system

question

mediodorsal/dorsomedial nu

answer

reciprocally connected to prefrontal cortex; connections w/ intralaminar nulei; input from amygdale, substantia nigra, temporal neocortex; lesion--memory loss (Wernicke-Korsakoff syndrome; mediodorsal nu role in expression of affect, emotion, behavior/limic fxn

question

centromedian nu

answer

largest intralaminar nu; reciprocally connected to motor cortex/Brodmann 4; input from globus pallidus, projects to striatum/caudate nu and putamen and projects diffusely to entire neocortex

question

pulvinar

answer

largest thalamic nu; reciprocal connections w/ association cortex of occipital, parietal, posterior temporal lobes; input from lateral and medial geniculate bodies and superior colliculus; role integration of visual, auditory, somesthetic input; destruction of dominant pulvinar--sensory dysphasia

question

ventral tier nuclei

answer

ventral anterior nu, ventral lateral nu, ventral posterior nu (VPL + VPM

question

ventral anterior nu

answer

input from globus pallidus and substantia nigra, projects diffusely to prefrontal cortex, orbital cortex, and premotor cortex/Brodmann 6

question

ventral lateral nu

answer

input from cerebellum/dentate nu, globus pallidus, and substantia nigra; projects to motor cortex/brodmann 4 and supplementary motor cortex/brodmann 6]

question

ventral posterior nu

answer

nu of termination of general somatic afferent/touch,pain,temp and special visceral afferent/taste; has 2 subnuclei: VPL--receives spinothalamic tracts and medial lemniscus, projects to somesthetic/sensory crotex/brodmann 3,1,2 VPM--receives trigeminothalamic tracts and projects to somesthetic/sensory crotex/brodmann 3,1,2; gustatory pathway from solitary nu projects via central tegmental tract to VPM and thence to gustatory cortex of: postcentral gyrus/brodmann 3b, frontal operculum and insular corex; taste is ipsi.

question

metathalamus

answer

lateral and medial geniculate body

question

lateral geniculate body

answer

visual relay nu; input from optic tract, projects to primary visual cortex/brodmann 17

question

medial geniculate body

answer

auditory relay nu (think of MEDIA!); input from brachium of inferior colliculus, projects to primary auditory cortex/brodmann 41-42

question

reticular nu of thalamus

answer

surrounds thalamus as thin layer of GABA neurons, lies btw external medullary lamina and internal capsule; receives excitatory collateral input from corticothalamic and thalamocortical fibers; projects inhibitory to thalamic nu from which it receives input; role in normal electroencephalogram readings

question

blood supply of thalamus

answer

1. posterior communicating artery, 2. posterior cerebral artery (thalamoperforating + thalamogeniculate arteries), 3. anterior choroidal artery

question

internal capsule

answer

layer of white matter separating caudate nuc and thalamus medially from lentiform nu (putamen + globus pallidus) laterally; ant limb is btw caudate nu and lentiform nu; genu contains corticonuclear fibers; posterior limb is btwn thalamus and lentiform nu, post limb has corticospinal/pyramid fibers as well as visual, auditory raditation, sensory/pain,temp, touch

question

blood supply of internal capsule

answer

*ant limb: medial striate branches of ACA and lateral striate/lenticulostriate branches of MCA; *genu: direct branches from internal carotid artery or pallidal branches of anterior choroidal artery; *post lim: branches of ant. chroidal artery adn lenticulostriate branches of MCA

question

ch18 hypothalamus

answer

division of diencephalon; 3 systems: ANS, endocrine, limbic; maintain homeostasis

question

hypothalamic nuclei and their fxns

answer

(next 11)

question

medial preoptic nu

answer

regulates release of gonadotropic hormones from ant. pit; sexually dimorphic nu, development depends on testosterone levels

question

suprachiasmatic nu

answer

input from retina; role in circadian rhythms

question

posterior hypothalamic nu

answer

thermal regulation/conservation and inc heat production; lesions-- inability to thermoregulate—(think: POIKILOTHERMIA!!)

question

anterior hypothalamic nu

answer

temp regulation, stimulates parasymp; destruction results in hyperthermia (think: anterior=head; HOT HEADS!!)

question

paraventricular nu

answer

synthesizes ADH, oxytocin, CRH; gives rise to supropticohypophyseal tract--projects to autonomic nuclei of brain stem and all levels of spinal cord; destructions--diabetes insipidus/watery urine

question

supraoptic nu

answer

makes ADH, oxytocin

question

dorsomedial nu

answer

stimulated--savage behavior

question

ventromedial nu

answer

satiety center, stimulated--inhibits urge to eat; bilateral destruction results in hyperpphagia, obesity and savage behavior

question

arcuate/infundibular nu

answer

contains neurons that make factors that stimulate or inhibit action of hypothalamus; gives rise to tuberohypophysial tract that terminates in hypophyseal portal system of infundibulum/medium eminence; contains neurons that produce Dopamin/prolactin inhibiting factor

question

mamillary nu

answer

input from hippocampal formation through postcommissural fornix; projects to anterior nu of thalamus through mamillothalamic tract (part of Papez circuit). Patients with alcoholism or Wernike's encephalopathy/B1-thiamine deficiency/have lesions in mamillary nu

question

lateral hypothalamic nu

answer

stimulated--induce eating; lesions--anorexia and starvation; (think: L for Labia/Lips)

question

major fiber systems of hypothalamus

answer

...

question

fornix

answer

largest projection to hypothalamus; projects from hippocampal formation to mamillary nu, ant. nu of thalamus, and septal area; fornix then projects from septal area to hippocampal formation

question

medial forebrain bundle

answer

traverses entire lateral hypothalamic area; interconnects orbitofrontal cortex, septal area, hypothalamus, and midbrain

question

mamillothalamic tract

answer

projects from mamillary nu to ant nu of thalamus/part of Papez circuit

question

stria terminalis

answer

major path from amygdala; interconnects septal area, hypothalamus, and amygdala

question

supraopticohypophysial tract

answer

conducts fibers from supraoptic and paraventricular nuclei to neurohypothalamus, and amygdala

question

tuberohypophysial/tuberoinfundibular tract

answer

conducts fibers from arcuate nu to hypophyseal portal system

question

hypothalamospinal tract

answer

contains direct descending autonomic fibers; fibers influence pregang symp neurons of intermediolateral cell column and preganglionic neurons of sacral parasymp nu; interruption above first thoractic segment T1 causes Horner's

question

anterior hypothalamus

answer

has excitatory effect on parasymp nervous system

question

posterior hypothalamus

answer

has excitatory effect on symp

question

temp regulation

answer

1. ant hypothalamus--regulates/maintains body temp, destruction--hyperthermia; 2. posterior hypothalamus--helps produce and conserve heat, destruction--inability to thermoregulate

question

water balance regulation

answer

paraventricular nu--ADH

question

Food intake regulation

answer

2 hypothalamic nuclei role in appetite: 1. ventromedial nu-stimulated-- inhibits urge to eat/destruction--hyperphagia,obseity,savage behavior 2. lateral hypothalamic (think "lips for eating")-stimulate--induces urge to eat/destruction--starvation and emaciation

question

diabetes insipidus

answer

polyuria, polydipsia; hypothalamic syndrome; lesions of ADH pathways to posterior pituitary

question

syndrome of inappropriate ADH secretion

answer

From over secretion of ADA; leads to hyponatremia; lung tumors or drug therapy/eg. Carbamazepine, chlorpromazine

question

craniopharyngioma

answer

congenital tumor from remnants of Rathke's Pouch; calcified; most common supratentorial tumor in children and most common cause of hypopituitarism in children; 1. pressure on chiasm--bitemporal hemianopia 2. pressure on hypothalamus--hypothalmic syndrome/adiposity,diabetes insipidus,disturbance of temp regulation,somnolence

question

pituitary adenomas

answer

intracranial tumor; amenorrhea, galactorrhea from a prolactin secreting adenoma; 1. pressure on chiasm--bitemporal hemianopia 2. pressur eon hypothalamus--hypothalamus syndrome

question

ch19

answer

limbic system

question

orbitofrontal cortex

answer

mediates conscious perception of smell; reciprocal connections with mediodorsal nu of thalamus; interconnected through medial forebrain bundle w/ septal area and hypothalamic nuclei

question

dorsomedial mediodorsal nu of thalamus

answer

reciprocal connections w/ orbitofrontal and prefrontal cortices and hypothalamus; receives input from amygdala, role in affective behavior and memory

question

ant. nu of thalamus

answer

input from mamillary nu through amillothalamic tract and fornix; projects to cingulate gyrus and major link in Papez circuit

question

septal area

answer

telencephalic structure; reciprocal connections with hippocampal formation through fornix and w/ hypothalamus through medial forebrain bundle; projects through stria medullaris (thalami) to habenular nu

question

limbic lobe

answer

includes subcallosal area, paraterminal gyrus, cingulate gyrus and isthmus, and parahippocampal gyrus, includes uncus; contains hippocampal formation and amygdaloid nuclear complex.

question

hippocampal formation

answer

sheet of archicortex jelly rolled into parahippocampal gyrus; fxn in learning, memory, recognition of novelty; receives input through entorhinal cortex and projects output through fornix; Major structures: 1. dentate gyrus--3 layered archicortex--contains granule cells that receive hippocampal input adn project output to pyramidal cells of hippocampus and subiculum; 2. hippocampus/cornu Ammonis--3 layered archicortex; contains pyramidal cells that project through fornix to septal area dn hypothalamus; 3. subiculum--receives input through hippocampal pyramidal cells; projects through fornix to mamillary nuclei and anterior nucleus of thalamus.

question

amygdaloid complex/amygdala

answer

basal nu underlies parahippocampal uncus; stimulated--human fear and signs of symp overactivity, animal cessation of activity and heightened attentiveness; lesion--placidity and hypersexual behavior

question

amygdaloid complex/amygdala input & output

answer

input: from sensory association cortices, olfactory bulb and cortex, hypothalamus and septal area, and hippocampal formation; output: through stria terminalis to hypothalamus and septal area; also to dorsomedial nu of thalamus

question

hypothalamus reciprocal connection

answer

with amygdala

question

limbic midbrain nuclei and associated NTs

answer

ventral tegmental area/Dopamine; raphe nuclei/Serotonin; locu ceruleus/NE

question

papez circuit

answer

includes: 1. hippocampal formation 2. mamillary nu 3. ant. thalamic nuc 4. cingulate gyrus/brodmann 23-24 5. entorhinal area/brodmann 28

question

Limbic System Structures "The Papez Circuit"//according to Dr. Mize

answer

1. Limbic Cortex: cingulate gyrus, parahippocampal gyrus, entorhinal cortex, orbitofrontal cortex 2. Hippocampal Formation 3. Amygdala 4. Septal nuclei, nucleus accumbens 5. Hypothalamus (mammillary bodies) 6. Thalamus: anterior and dorsomedial nu

question

kluver-bucy syndrome

answer

bilateral ablation of anterior temporal lobes including amygdaloid nuclei; psychic blindness/visual agnosia, hypoerphagia, docility/placidity, hypersexuality

question

amnestic/confabulatory syndrome

answer

bilateral infarction of hippocampa formation i.e. hippocampal branches of posterior cerebral arteries and ant. choroidal arteries of internal carotid arteries; anterograde amnesia; memory loss suggests hippocampal pathology

question

Foster kennedy syndrome

answer

meningioma of OLFACTORYgroove (Foster Kennedy—think Foul-smelling sKunk); compresses olfactory tract and optic n; ipsi anosmia and optic atrophy and contra papilledema as a result of inc ICP

question

hippocampus

answer

most epileptogenic part of cerebrum; lesions-psychomotor attacks; sommer's sector sensitive to ischemia

question

bilateral transection of fornix

answer

acute amnestic syndrome/i.e. inability to consolidate short-term memory into long-term

question

wernicke's encephalopathy

answer

thiamine/B1 deficiency; triad: ocular disturbances and nystagmus, gait ataxia, mental dysfxn; pathologic features: mamillary nuclei, dorsomedial nuclei of thalamus, periaqueductal gray and pontine tegmentum

question

Strachan's syndrome

answer

high dose thiamine therapy (thiamineATP production; think "high strung//high energy"); triad: spinal ataxia, optic atrophy, nerve deafness

question

bilateral destruction or removal of cingulate gyri

answer

loss of initiative and inhibition and dulling of emotions; memory ok; lesions of ant. cingulate gyri--placidity; cingulectomy to Tx severe anxiety and depression

question

Benzodiazepines

answer

enhance the effect of the neurotransmitter gamma-aminobutyric acid (GABA), which results in sedative, hypnotic (sleep-inducing), anxiolytic (anti-anxiety), anticonvulsant, muscle relaxant and amnesic action. Useful in treating anxiety, insomnia, agitation, seizures, muscle spasms, alcohol withdrawal and as a premedication for medical or dental procedures. Short- and intermediate-acting --treatment of insomnia; longer-acting benzodiazepines --treatment of anxiety.

question

ch20 cerebellum (3 primary fxns)

answer

1. maintenance of posture and balance, 2. maintenance of muscle tone, 3. coordinationof voluntary motor activity

question

3 cerebellar peduncles

answer

1. superior: major output from cerebellum-- the dentatothalamic tract (tract terminates in ventral lateral nu of thalamus; one major afferent pathway--VENTRAL spinocerebellar tract 2. middle: receives pontocerebellar fibers, project to neocerebellum/pontocerebelllum 3. inferior: 3 major afferent tracts (DORSAL spinocerebelllar tract, CUNEOcerebellar tract, OLIVOcerebellar tract from contra inferior olivary nu)

question

3 layers

answer

1. molecular, 2. purkinje, 3. granule

question

purkinje cells

answer

output from cerebellar cortex/ inhibitory output/GABA to cerebellar and vestibular nuclei; excited by parallel and climbing fibers and inhibited by GABAergic basket and stellate cells

question

granule cells

answer

excite/Glu Purkinje, basket, stellate, and Gogli cells; inhibited by Golgi cells and excited by mossy fibers

question

parallel fibers

answer

axons of granule cells; fibers extend into molecular layer

question

mossy fibers

answer

afferent excitatory fibers of spinocerebellar, pontocerebellar, and vestibulocerebellar tracts; terminate as mossy fibers rosettes on granule cell dendrites; excite granule cells to discharge through parallel fibers

question

climbing fibers

answer

afferent excitatory/Aspartate of olivocerebellar tract; fibers from contra inferior olivary nu; terminate on neurons of cerebellar nuclei and dendrites of Purkinje cells

question

cerebellar pathways

answer

...

question

purkinje cells of cerebellar cortex

answer

project to cerebellar nuclei (e.g. dentate emboliform, globose, fastigial nuclei)

question

dentate nucleus

answer

major EFFECTOR nu; give rise to dentatothalamic tract that projects through SUPERIOR cerebellar peduncle to contra ventral lateral nu of thalamus; decussation of superior cerebellar peduncle is in caudal midbrain tegmentum

question

ventral lateral nu of thalamus

answer

receives dentatothalamic tract; projects to primary motor cortex of precentral gyrus/Brodmann 4

question

motor cortex/motor strip/brodman 4

answer

input from ventral lateral nu of thalamus, projects as corticopontine tract to pontine nuclei

question

pontine nuclei

answer

input from motor cortex; axons project as pontocerebellar tract to contra cerebellar cortex, where they terminate as mossy fibers--completing circuit

question

cerebellar dysfxn

answer

triad: 1. hypotonia, 2. dysequilibrium, 3. dyssynergia (loss of coordinated muscle activity; dysmetria, intention tremor, failure to check movts. Nystagmus, dysdiadochokinesia, dysrhythmokinesia; cerebellar nystagmus is coarse; more pronounced when pt looks fwd to side of lesion)

question

cerebellar syndromes and tumors

answer

...

question

ant. vermis syndrome

answer

leg region of ant lobbe; atrophy of rostral vermis; caused by alcohol abuse; gait, trunk and leg dystaxia

question

post. Vermis syndrome

answer

flocculonodular lobe; brain tumors in children common cause/medulloblastomas or ependymomas; truncal dystaxia

question

hemisphereic syndrome

answer

cerebellar hemisphere; result of brain tumor/astrocytoma or abscess/secondary to otitis media or mastoiditis; arm, leg, gait dystaxia and ipsi cerebellar signs

question

cerebellar tumors

answer

1. astrocytomas, 2. medulloblastomas 3. ependymomas--4th ventricle common--obstruct CSF--hydrocephalus; children--70% brain tumor in posterior fossa; adults--70% brain tumor in supratentorial compartment

question

ch21

answer

basal nuclei/ganglia and striatal motor system

question

Know the major sources of arteries which penetrate into the basal structures of the forebrain and diencephalon, including the recurrent artery of Huebner (ACA), anterior choroidal artery (int. carotid), the lenticulostriate arteries (MCA); and the thalamopenetrating and thalamogeniculate arteries (PCA)

answer

*Recurrent artery of Heubner - comes off of the ACA. Feeds most anterior aspect of the putamen and the head of the caudate nucleus*Anterior Choroidal - comes off Internal Carotid. Supplies the cadual aspects of the putamen and the tale of the caudate.*Lenticulostriates - branch off the MCA. Innervate middle aspects of the putamen, globus pallidus, and broad regions of the caudate nucleus.*Thalamoperforating arteries - branch from PCA. Supplies bulk of the thalamus excluding the posterior portion*Thalamogeniculate arteries - from PCA. Supplies the posterior portion including the Lateral geniculate nucleus(visual system) and Medial geniculate nucleus(auditory system)

question

basal nuclei/ganglia

answer

caudate nu, putamen, globus pallidus

question

striatum

answer

caudate nu & putamen

question

corpus striatum

answer

lentiform nu + caudate nu

question

lentiform nu

answer

globus pallidus + putamen

question

claustrum

answer

lies btw lentiform nu and insular cortex; reciprocal connections btw sensory cortices/visual cortex

question

parkinson dz

answer

degenerative; affects substania nigra and its projections to striatum (to stimulate movt.); depletion of dopamine in substantia nigra and striatum; loss of melanin-containing dopaminergic neurons in substantia nigra; lewy bodies, progressive supranuclear palsy.

question

MPTP-induced parkinsonism

answer

analog of meperidine/demerol; destroys dopaminergic neurosn in substantia nigra

question

hungtinton's dz/chorea

answer

inherited auto dominant; single gene defect on chrom. 4; degeneration of cholinergic and GABA neurons of striatum; gyral atrophy in frontal and temporal lobe

question

glutamate excitotoxicity

answer

glu released in striatum binds receptors on striatal neurons-->AP; Glu is bound to NmethylDaspartate receptor instead of being removed from extracellular space by astrocytes-->lots of influx of Ca and cell death, neuronal death in cerebrovascular accidents/stroke; choreiform movts, hypotonia, progressive dementia

question

syndenham's chorea/st. vitus dance

answer

girls, after rheumatic fever, chorea

question

chorea gravidarum

answer

during 2nd trimester of pregnancy; history of sydneham chorea

question

hemiballism

answer

from vascular lesion of SUBTHALAMIC nu; violent contra flinging movt of one or both extremities

question

hepatolenticular degeneration/wilson's dz

answer

auto recessive; defect in metabolism of Cu; gene on chrom 13; choreiform or athetotic movt, rigidity, wingbeating tremor; lesions in lentiform nu; copper deposition in limbus of cornea--corneal Kayser-Fleischer ring--pathognomonic sign; deposition of Cu in liver--multilobar cirrhosis; psychosis, personality disorders, dementia; low serum ceruloplasmin, elevated urinary excretion of CU, inc CU in liver biopsy; Tx: penicillamine chelator

question

tardive dyskinesia

answer

repetitive choreic movt affects face and trunk; Tx: phenothiazines, butyrophenones or metoclopramide

question

ch 22 cerebral cortex

answer

thin, gray covering of both hemispheres of brain; 2 types: 1. neocortex/90%, allocortex/10%; motor cortex is thickest/4.5mm; visual cortex thinnest/1.5mm

question

neocortex

answer

6 layers: II & IV--mainly afferent, V & VI mainly efferent; IV--internal granular layer; VI: internal pyramidal layer-->corticobular, corticospinal and corticostriatal fibers; IV contains giant pyramidal cells of Betz/in Brodmann 4; VI: multiform layer--major source of corticothalamic fibers, gives rise to projection, commissural and association fibers

question

fxnal areas of cerebral cortex

answer

frontal lobe, parietal lobe, temporal lobe, occipital lobe

question

frontal lobe

answer

motor cortex/brodmann 4 and premotor cortex/brodmann 6, frontal eye field/brodmann 8, broca's speech area/brodmann 44-45, prefrontal cortex/brodmann 9-12 and 46-47

question

parietal lobe

answer

sensory cortex/brodman 3,1,2; superior parietal lobule/brodmann 5 and 7; inferior parietal lobule of DOMINANT hemisphere (Gerstmann syndrome: R and L confusion, finger agnosia, dysgraphia, dyslexia, dyscalculia, contra hemianopia/lower quadrantanopia); inferior parietal lobule of NONDOMINANT hemisphere (topographic memory loss, anosognosia, construciton apraxia, dressing apraxia, contra sensory neglect, contra hemianopia/lower quadrantanopia

question

temporal lobe

answer

1. primary auditory cortex/brodmann 41-42; 2. Wernicke's speech area in dominant hemisphere/brodmann 22 (repetitive, fluent aphasia, no comprehension); 3. Meyer's loop (pie in the sky); 4. olfactory bulb, tract and primary cortex/brodmann 34; 5. hippocampal cortex/archicortex (difficulty short-term into long-term; 6. anterior temporal lobe (including amygdaloid nu, bilateral damage: Klaver-Bucy); 7. inferomedial occipitotemporal cortex, bilateral lesions: inability to recognize once-familiar faces/prosopagnosia

question

olfactory bulb, tract and primary cortex/brodmann 34

answer

ipsi anosmia; irritative uncus lesion/psychomotor epilepsy--olfactory and gustatory hallucinations; olfactory groove meningiomas (anosmia, foster kennedy syndrome); esthesioneuroblastomas/olfactory neuroblastomas)

question

occipital lobe

answer

bilateral lesions--cortical blindness, unilateral lesions--contra hemianopia/quadrantanopia

question

Human Memory System

answer

1. Medial Temporal Lobe System: subserves declarative memory. Includes hippocampal structures as well. 2. Medial Diencephalic System: subserves declarative memory. Involves mammillary bodies, anterior and dorsomedial nu. of thalamus, cingulate cortex. 3. Neostriatal System: subserves procedural memory. Habits, motor skills 4. Prefrontal Cortex: working memory

question

focal destructive hemispheric lesions and symptoms

answer

...

question

Aphasias

answer

are disorders of language that result mainly from lesions in the lateral aspect of the left hemisphere. Aphasias may be caused by a stroke involving superficial branches of the left middle cerebral artery (MCA). Patients with an aphasia commonly have agraphia and difficulty in repetition or naming.

question

cerebral dominance

answer

determined by Wada test; sodium amobarbital/Amytal injected into carotid artery; if pt becomes aphasic--anesthetic was administered to dominant hemisphere

question

dominant hemisphere

answer

usually Left hemisphere; vocal naming; propositional language (grammar,syntax,semantics), speech and calculation

question

nondominant hemisphere

answer

usually Right hemisphere; 3D spatial perception and nonverbal ideation; allows superior recognition of faces

question

corpus callosum syndrome/lesions

answer

...

question

split brain syndrome

answer

disconnection syndrome--from transection of corpus callosum

question

anterior corpus callosum lesion

answer

akinetic mutism or tactile anomia

question

posterior corpus callosum/splenium lesion

answer

alexia (don't know how to say) w/o agraphia (can write)

question

callosotomy

answer

Tx for drop attacks/colloid cyst of 3rd ventricle

question

ch 23

answer

NTs

question

ACh

answer

in basal nu of Meynert (area degenerates in Alzheimer's Dz)

question

catecholamines

answer

DA, Epi, NE

question

serotonin/5HT

answer

in raphe nuclei of brain stem//depression and insomnia

question

opioid peptides/endogenous opiates

answer

endorphins (b-endorphin in brain) in hypothalamus, enkephalins (in globus pallidus, role in pain suppression)

question

nonopioid neuropeptides

answer

substance P (pain transmission) concentrated in substantia nigra, substance P is reduced in pts with Hungtingon's dz; 2. somatostatin--inc in Huntington's dz

question

amino acid transmitters

answer

inhibitory: GABA (purkinje, stellate, basket, golgi cells of cerebellar cortex), glycine; excitatory: Glu (NMDA receptors--longt term potentiation/memory process, kindling and seizure activity, neurotoxic in certain conditions, Glu excitotoxicity), aspartate, nitric oxide

question

parkinson dz

answer

degeneration of DA neurons in pars compacta of substantia nigra; reduction of DA in striatum and substantia nigra

question

hungtinton's dz/chorea

answer

loss of ACh and GABA neurons in striatum/caudatoputamen

question

Alzheimer's dz

answer

Degeneration of cortical neurons and cholinergic neurons in basal nucleus of Meynert; (Brain Areas Affected: medial temporal cortex, hippocampus, n. basalis of Meynert, locus coeruleus, Raphe nuclei, frontal ctx.); loss of choline acetyltransferase//loss of ACh transmitter in cerebral cortex; Some causes: 1. Amyloid precursor transmembrane protein (APP), 2. APOE, 3. Generation of plaques; characterized in the brain by abnormal clumps (amyloid plaques) and tangled bundles of fibers(neurofibrillary tangles) composed of misplaced proteins. Senile Plaques: composed of ß-amyloid deposits, usually contained within the extracellular space. Due to cleavage by ß secretase enzyme. Produces apoptosis. Neurofibrillary tangles: composed mainly of hyperphosphorylated microtubule- associated Tau proteins w/i neurons.

question

Mechanism of Alzheimer's DZ (Misfolded proteinsplaque)

answer

1. Abnormal cleavage by ß-secretase enzyme 2. γ-scretase cleaves Intracellular terminus 3. APOE4 associates with an increase in amyloid plaques and neurofibrillary tangles (NFTs); ApoE gene in Chromosome 19, 34kDa protein/ transports cholesterol in the blood, In brain - ApoE is produced by astrocytes; also in CSF (i) stressors/injurious agentsinc APOE to repair or remodel the damaged neurons.(ii) Neuronal APOE is cleaved by proteolysis to generate C-terminal-truncated fragments; (iii) APOE4 fragments cause cytoskeletal changes, such as Tau phosphorylation and NFT formation. (iv) APOE4 induces mitochondrial dysfunction, whereas changes in the cytoskeleton and mitochondria contribute to neurodegeneration.

question

myasthenia gravis

answer

autoantibodies against ACh receptor on skeletal muscle; block postgang ACh binding site; muscle use cause fatigue

question

lambert-eaton myasthenic syndrome

answer

presynaptic defect of ACh release; weakness of limb muscles but not bulbar muscles; neoplasms, strength improves with use

question

ch 24

answer

apraxia, aphasia, dysprosody

question

apraxia

answer

inability to perform motor fxn in presence of intact motor and sensory systems and normal comprehension

question

ideomotor apraxia/idiokenetic apraxia

answer

loss of ability to perform intransitive or imaginary gestures; can't do complicated motor task/saluting,blowing a kiss; lesion in Wernicke's, Bucco-facial or facial-oral apraxia--idiomotor apraxia, facial apraxia most common apraxia

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ideational apraxia/ideatory apraxia

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inability to show use of real objects (can't do multistep sequence), misuse of obj. due to disturbance of identification/agnosia; lesion in Wernicke's

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construction apraxia

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inability to draw geometric figure, if draws only right half of clock/hemineglect--lesion is located in R inferior parietal lobule

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gait apraxia

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inability to use lower limbs properly; difficulty in lifting feet from floor, a frontal lobe sign seen with normal-pressure hydrocephalus (gait apraxia, dementia, incontinence)

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aphasia

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impaired communication by speech, writing, or signs/loss spoken language; lesions in dominant hemisphere

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types of aphasia

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broca's motor aphasia, Wernicke's sensory phasia, conduction aphasia, transcortical motor aphasia, transcortical mixed aphasia, transcortical sensory aphasia (fluent, repetition, no comprehension), global aphasia, thalamic aphasia (thought disorder--schiz, chronic drug-induced psychosis)--fluent paraphasic speech, comprehension and repetition is ok.

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Broca's aphasia/Types of Language Disorders:

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Disturbance in speech production. Expressive or motor aphasia. Non-fluent, agrammatical.

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Wernicke's aphasia/Types of Language Disorders:

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Disturbance in comprehension. Receptive or sensory aphasia. Fluent but with paraphasias

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Conduction aphasia/Types of Language Disorders:

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Difficulty in translating what is heard into an appropriate response. Disturbances of repetition and spontaneous speech. Produced by damage to arcuate fasciculus, other pathways.

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Transcortical aphasia/Types of Language Disorders:

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sensory or motor; similar to Broca's or Wernicke's but repetition is spared. Produced by watershed infarcts.

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Global Aphasia/Types of Language Disorders:

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major disturbance in all language functions.

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Anomic aphasia/Types of Language Disorders:

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disturbance in the production of single words, especially nouns. Intact comprehension, repetition.

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basal ganglia

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lesions of ANTERIOR basal ganglia--nonfluent aphasia; lesion of POSTERIOR basal ganglia result in fluent aphasia

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watershed infarcts

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infarction of boundary zones of ant, middle, post cerebral arteries; areas vulnerable to hypoperfusion--may separate Broca and Wernicke's speech areas from surrounding cortex; cause motor, mixed and sensory transcortical aphasias

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dysprosody

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nondominant hemi language deficit; affected: emotionality, inflection, melody, emphasis, gesturing

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expressive dysprosody

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lesion to BROCA area but in nondominant hemisphere; can't express emotion or inflection in speech

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receptive dysprosody

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lesions to WERNICKE, in nondominant hemisphere; can't comprehend emotionality or inflection in speech they hear

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