Videos 2

Question 1

Case: 47 y/o man with R cerebellar hemispherectomy secondary to large cerebellar stroke

Decreased coordination and fine-controlled movement as evidenced by FNF; movements choppy and slow, rapid alternating movements decreased in speed, difficulty with coordination of LE by heel knee shin, difficulty standing (unsteady) and walking (rigid uncoordinated steps)

Few months later - sleep slow and slurred, arm coordination improving, shaky in hand at times, R>L, unable to walk unassisted, can stand and walk with a walker, arm strength intact bilaterally

Answer 1

Ataxia due to bilateral PICA infarctions

Question 2

What are the cardinal features of cerebellar dysfunction?

Answer 2

Disturbances in motor control, muscle tone regulation, coordination of skilled movements

May find ataxia, dysmetria, dysdiadochokinesia, impaired checking response, scanning/slurred speech, wide-based stance and gait

Question 3

Arterial supply of the cerebellum?

Answer 3

PICA (from vertebral)

AICA, SCA (from basilar)

Question 4

What does PICA supply?

Answer 4

Lateral medulla
Vermis, adjacent cerebellar hemisphere
Cortical surface of tonsil and cerebellar hemisphere

Question 5

What does AICA supply?

Answer 5

Lateral tegmentum of the lower 2/3 of the pons
Ventrolateral cerebellum
Facial and auditory nerves

Question 6

What does SCA supply?

Answer 6

Superolateral cerebellar hemisphere
Superior cerebellar peduncle
Dentate nucleus
Part of the middle cerebellar peduncle

Question 7

Features of cerebellar infarction?

Answer 7

Severe vertigo, N/V, ataxia

Loss of balance, difficulty maintaing posture, standing, walking

Question 8

Case - 31 y/o female, progressive history of gait and limb incoordination and head tremors

Bobbing, shaky head, trouble walking and speaking, difficulty getting words out, no difficulties swallowing, numbness/tingling in feet and mouth, family history of similar problems in mother and sister

Eyes remain stationary despite shaking head (intact VOR), difficulty writing due to shakiness, difficulty with fine motor movements, decreased coordination by FNF due to shaking, unsteady walk

Diplopia, abnormal EOM (esotropia), head and hand tremor, hypoactive reflexes, wide-based ataxic gait

Answer 8

Hereditary spinocerebellar ataxia

Question 9

Features of spinocerebellar ataxia type 1?

Answer 9

Begins with gait ataxia
Develop dysarthria and dysphagia over time
Associated symptoms include ophthalmoparesis, spasticity, and choreoathetosis

Question 10

Presentation: 44 y/o female, long history of neuro symptoms beginning in high school (1970s) - paraesthesias, dizziness, tiredness

1980 - acute onset vertigo, lower extremity weakness, fatigue

1996 - insidious onset of progressive difficulties with urinary incontinence, weakness, and poor balance

Currently - slight nystagmus looking laterally right; when looking left, L eye moves laterally but R eye remains central with slight nystagmus

Unsteady narrow gait, unable to turn sharply

Answer 10

Bilateral internuclea ophthalmoplegia 2/2 MS

Question 11

Most common symptoms at the onset of MS?

Answer 11

Visual or oculomotor weakness or sensory disturbances and incoordination

Question 12

What causes an INO?

Answer 12

Horizontal disconjugation gaze palsy

Paramedian pontine reticular formation (PPRF)
Abducens nucleus interneurons

To look left, the L lateral rectus (CN 6) and R medial rectus (CN 3) activate synchronously

Axons of CN 6 interneurons cross to contralateral side in lower pons and ascend to the MLF to the contralateral oculomotor nucleus

R INO = disrupted R MLF, poor adduction in R eye

Question 13

Presentation of INO?

Answer 13

Adduction weakness of one eye and mononculear nystagmus of the abducting eye

Weakness results from disrupted signals carried by the MLF destined for CN III

Question 14

Presentation: 27 y/o AA woman with several episodes of neuro deficits

First episode - marked fatigue, decreased vision, unsteadiness

Second episode - decreased vision in both eyes

Third episode - decreased vision, disequilibrium

Fourth episode - decreased vision, gait unsteadiness

Loss of balance for 2 weeks, blurred visino, eyes not focusing, R eye would move faster than L, right leg had abnormal temperature sensation, fatigue, nystagmus when looking R, superior, and inferior

Slow, unsteady, widened gait

Difficulty walking heel-to-toe

MRI: T2 signal in pons, mostly on the left, and bilateral subcortical white matter

Answer 14

Nystagmus and ataxia 2/2 relapsing-remitting MS

Question 15

What is relapsing-remitting MS?

Answer 15

Most common form

Dysfunction occurs and may increase over days or week, plateaus, resolves over days or weeks

Question 16

Presentation: following surgery of an intracranial mass lesion, 60 y/o F developed a droopy left eyelid and diplopia

L eyelid closed, L pupil unreactive to direct light, R pupil reactive to light directly, consensual constriction of R pupil when light shined in L eye, lateral L gaze intact, R eye moves lateral, L eye remains central look to the R; inferior and upserior -> R eye moves, L eye central/fixed

L eye ptosis, L eye extropia and hypotropia (down and out), anisocoria, no direct or consenusal L eye constrction

Answer 16

Post-operative acute L CN III palsy

Question 17

Features of CN III palsy?

Answer 17

Eyelid ptosis
Pupillary dilation
Impaired pupillary reaction to light
Limitation of adduction, supraduction, infraduction

Question 18

What does CN III innervate?

Answer 18

Levator palpebrae superioris, superior, inferior, and medial recti, inferior obliques, pupillary constrictors

Question 19

Where can CN III lesions occur?

Answer 19

Midbrain (nucleus or fasciculus)
Subarachnoid space
Cavernous sinus
Superior orbital fissure
Orbit

Question 20

Pathway of CN III?

Answer 20

Midbrain (rostral to CN IV nucleus) nucleus -> fascicular portion travels ventrally traversing the red nucleus, exits anteriorly medial to the cerebral peduncles

In the subarachnoid space, nerve passes between posterior cerebral and superior cerebellar arteries

Enters lateral wall of cavernous sinus

At superior orbital fissure, divides into superior division (levator palpebrae and superior rectus) and inferior division (medial and inferior recti, inferior oblique, pre-synaptic parasympathetic outflow)

Question 21

Pupilloconstrictor is innervated by ___ system; dilator is innervated by ___ system.

Answer 21

Parasympathetic; sympathetic

Question 22

What nerves are in the cavernous sinus?

Answer 22

III, IV, VI, V1, sympathetic and parasymapthetic connections

Question 23

Blood supply to cavernous cranial nerves?

Answer 23

Arises from inferolateral trunk of the ICA and sometimes the accessory meningeal artery

Question 24

CN III palsy associated with a small pupil?

Answer 24

Horner’s syndrome

Question 25

What are signs of aberrant CN III regeneration?

Answer 25

Retraction and elevation of the lid on downward gaze

Elevation of the involved lid on attempted adduction

Retraction of the globe on attempted vertical eye movements

Adduction of the involved eye on attempted elevation or depression

Lack of pupillary reactivity to light, but adequate response when the medial rectus muscle, inferior rectus muscle, or elevators of the eye are activated

Delayed onset abduction defect

Question 26

Case: 82 y/o male, history HTN, HLD, referred for evaluation of non-positional headaches and sudden onset binocular diplopia with horizontal separation of the images that were worse in the distance; no associated scalp or occipital tenderness, eyelid ptosis, history of thyroid disease, no diurnal variation of diplopia, no fatigability, no hx DM, sore shoulders or hips, jaw claudication

Exam: impaired abduction (LR) of R eye and nasal deviation (esotropia) of R eye in center gaze

Side-by-side double vision, worse when looking right and straight ahead, separation of images worse when looking right and far vs. right and near, some nausea and lightheadedness

R eye remains more central and fixed while L eye is turned slightly inward, decreased lateral movement of R eye (more central) compared to normal L eye when looking right. Left lateral, superior, and inferior gaze intact for both eyes

MRI: changes compatible with small vessel ischemic disease; no brainstem acute changes on DWI

MRA - minimal tortuosity of vertebrobasilar system

Answer 26

CN VI palsy

Question 27

Pathway of abducens nerve?

Answer 27

Nucleus located in dorsal lower pons, exits brainstem ventrally at the level of the horizontal sulcus between the pons and medulla, courses anterolaterally passing over the petrous apex to enter the lateral wall of the cavernous sinu

Enters the orbit through the superior orbital fissure with CN III and IV

Question 28

Most common cause of CN VI palsy in older adults?

Answer 28

Microvascular occlusion of the nerve; most recover over a period of 3-6 months

Question 29

Case: 57 y/o male evaluated because of a 3-4 month history of progressive unilateral sensorineural hearing loss and subjective nonpulsatile tinnitus of the R ear

MRI: internal auditory canals demonstrating a small enhancing mass

Answer 29

Small R vestibular schwannoma

Question 30

If bilateral vestibular schwannomas, suspect what condition?

Answer 30

NF2

Question 31

Cause of autonomic signs in cluster headache?

Answer 31

Sympathetic paresis and parasympathetic overactivity

Question 32

Rx cluster headaches?

Answer 32

High-flow concentrated oxygen (acute)

Verapamil (#1), ergotamine, lithium carbonate, methysergide, prednisone, depakote, topiramate (prophylactic)

Question 33

Presentation: 31 y/o obese normotensive female with long-standing headaches, visual scotomata, bilateral papilledema, enlarged blind spots on visual field testing

Remainder of exam was unremarkable

Neuroimaging - normal brain MRI and MRV (excludes mass, cerebral venous thrombosis)

LP elevated opening pressure, normal CSF

Answer 33

Pseudotumor cerebri

Question 34

Diagnostic criteria for pseudotumor cerebri?

Answer 34

1. Signs and symptoms of increased ICP (headaches, transient visual obscurations, and horizontal diplopia due to unilateral or bilateral CN VI palsy)
2. Normal neuroimaging (MRI and MRV preferably)
3. Increased opening CSF pressure (>250) with normal composition

Question 35

Rx papilledema?

Answer 35

Weight loss if overweight

Diuretics like acetazolamide or furosemide

Question 36

Most common seizure type in adults? Most common site of epileptogenic focus?

Answer 36

Complex partial seizure

Temporal lobe (medial temporal lobe)

Question 37

What aspects of a seizure may indicate a contralateral epileptogenic region?

Answer 37

Forced and sustained head deviation and dystonic posturing of the upper extremity

Question 38

What aspects of a seizure may indicate an ipsilateral focus?

Answer 38

Unilateral upper extremity automatisms

Question 39

What indicates a dominant-hemisphere seizure?

Answer 39

Post-ictal dysphagia