USMLE and Neuroanatomy 3/16/14

Question 1

What are characteristics of normal aging?

Answer 1

Occasional forgetfulness, difficulty word finding, difficulty falling asleep, low energy

Question 2

Type of aphasia: word-finding difficulty

Answer 2

Expressive / non-fluent aphasia

Question 3

In age-related expressive/non-fluent aphasia, what is the etiology?

Answer 3

Impairment of dominant frontal lobe function, age-related

Question 4

Diagnosis of dementia requires:

Answer 4

impairment in daily functioning

Question 5

Anterior circulation of the brain includes what vessels?

Answer 5

ICA and its branches (ACA, MCA)

Question 6

Posterior circulation of the brain includes what vessels?

Answer 6

Paired vertebral arteries —> basilar artery —> paired PCAs

Question 7

ACA stroke: characteristic features

Answer 7

Contralateral motor/sensory deficits leg>arm, urinary incontinence, gait apraxia, primitive reflexes, abulia, paratonic rigidity

Question 8

Pronator Drift

Answer 8

sensitive test for UMN disease that pt may not otherwise notice; weakness in supination results in dominant pronation (pt with eyes closed)

Question 9

Wernicke’s Encephalopathy: diagnostic triad

Answer 9

encephalopathy, oculomotor dysfunction, gait ataxia

Question 10

Subarachnoid hemorrhage: clinical features

Answer 10

Worst headache of life; due to ruptured berry aneurysm; meningeal irritation (neck stiffness), uncommon focal deficits

Question 11

Subarachnoid hemorrhage: complications

Answer 11

Rebleed (first 24h), vasospasm (after 3d), increased ICP; seizures; hyponatremia (from SIADH)

Question 12

Subarachnoid hemorrhage: diagnosis

Answer 12

Noncontrast CT; LP; xanthochromia in CSF (usually 6h after onset), CTA-A to identify source

Question 13

Subarachnoid hemorrhage: treatment

Answer 13

Coiling and/or stenting; nimodipine & hyperdynamic tx to reduce vasospasm

Question 14

Myasthenia Crisis: definition

Answer 14

Life-threatening condition characterized by weakness of respiratory and pharyngeal muscles

Question 15

Myasthenia Crisis: treatment

Answer 15

Endotracheal intubation, w/d of AChEis for a few days; treat concomitant infection; monitor PFTs

Question 16

Treatment of acute exacerbations of MS

Answer 16

Corticosteroids (IV)

Question 17

GBM: CT/MRI characteristic findings

Answer 17

butterfly appearance w/central necrosis

Question 18

High-grade astrocytoma: CT/MRI characteristic findings

Answer 18

Heterogenous, serpiginous contrast enhancement

Question 19

GBS: predisposing conditions

Answer 19

campylobacter infection, vaccination

Question 20

Craniopharyngioma

Answer 20

benign tumors arising from Rathke’s pouch; bimodal age distribution (kids and 55-65yo); cysts filled w/oily material; located above sella turcica

Question 21

Craniopharyngioma: clinical feature

Answer 21

bitemporal hemianopia (compression of optic chiasm)

Question 22

Cauda Equina Syndrome: features

Answer 22

bilateral severe radicular pain; saddle anesthesia; asymmetric motor weakness; hyporeflexia/areflexia; late-onset bowel & bladder dysfunction

Question 23

Conus Medullaris Syndrome: features

Answer 23

sudden onset severe back pain; perianal hypo/anesthesia; symmetric motor weakness; early-onset bowel and bladder dysfunction

Question 24

CES v. CMS: LMN or UMN signs?

Answer 24

CES: LMN
CMS: UMN + LMN

Question 25

Conus Medullaris nerve roots

Answer 25

S1-S5

Question 26

Treatment for CES?

Answer 26

Emergent MRI, neurosurgical intervention, IV glucocorticoids

Question 27

Cavernous Sinus: contents

Answer 27

ICA, CN III, IV, V, VI

Question 28

Cavernous Sinus Thrombosis: pathophys

Answer 28

facial/ophthalmic venous system is valveless

Question 29

Cavernous Sinus Thrombosis: clinical features

Answer 29

headahce, binocular palsies, periorbital edema, hypoesthesia/hyperesthesia

Question 30

Cavernous Sinus Thrombosis: treatment

Answer 30

antibiotics, prevent herniation

Question 31

Cavernous Sinus Thrombosis: red flags

Answer 31

headache, bilateral periorbital edema, CN III, IV, V, VI deficits

Question 32

CNs that exit in the midbrain:

Answer 32

III, IV

Question 33

CNs that exit in the pons:

Answer 33

V, VI, VII, VIII

Question 34

CNs that exit in the medulla:

Answer 34

IX, X, XII

Question 35

CNs that exit medially:

Answer 35

MOTOR- III, IV, VI, XII

Question 36

CNs that exit laterally:

Answer 36

MIXED- V, VII, IX, X

Question 37

Most cranial nerves exit ventrally or dorsally?

Answer 37

Ventral/ventralateral

Question 38

Which CN exits dorsally?

Answer 38

IV, just posterior or below the inferior colliculi

Question 39

Superior Cerebellar Peduncle

Answer 39

Efferent route from cerebellum; projections from deep cerebellar nuclei —> red nucleus and thalamus (VL)

Question 40

Middle Cerebellar Peduncle

Answer 40

Largest CP, contains fibers from contralateral pontine nuclei —> mossy fibers in cerebellar cortex

Question 41

Inferior Cerebellar Peduncle

Answer 41

Input route to cerebellum, contains: - Crossed olivocerebellar fibers - Uncrossed posterior spinocerebellar and cuneocerebellar fibers, vestibulocerebellar fibers, and other cerebellar afferents

Question 42

Spinocerebellar tract

Answer 42

Clarke’s Nucleus (T1-L2) —> info about biomechanics state of muscle spindles and GTOs in Lower Extremity

Question 43

Cuneocerebellar tract

Answer 43

External cuneate nucleus (medulla) —> info about biomechanics state of muscle spindles and GTOs in upper extremity

Question 44

Corticospinal tract

Answer 44

precentral gyrus (motor cortex) —> post limb of internal capsule —> cross in pyramidal decussation (medulla) —> lateral corticospinal tract —> synapse in anterior horn of spinal cord

Question 45

Anterolateral (Spinothalamic) System

Answer 45

Pain, temp, crude touch; afferents cross 1-2 levels ABOVE their dorsal roots

Question 46

Anterolateral (Spinothalamic) System: path

Answer 46

Dorsal root ganglion —> cross 1-2 spinal levels above —> anterolateral pathway —> synapse in thalamus (VPL nucleus) —> primary somatosensory cortex

Question 47

Dorsolateral / Medial Lemniscus System

Answer 47

vibration, proprioception, light touch

Question 48

Dorsolateral / Medial Lemniscus System: path

Answer 48

Dorsal root ganglion —> dorsal columns —> gracilis/cuneate nucleus in medulla —> sensory decussation —> medial lemniscus —> synapse in thalamus (VPL) —> primary somatosensory cortex