Neuro 3

Question 1

What is the water in ear test called and what does it do

Answer 1

Cold caloric testing

Ice water in ear and observe for conjugate eye deviation toward the ear injected (with nystagmus in the opposite direction?)

Question 2

Cranial nerves involved in pupillary reflex

Answer 2

II (afferent) and III (efferent)

Question 3

CN involved in oculocephalic reflex

Answer 3

VIII (afferent); III, IV, VI (efferent)

Question 4

CN involved in caloric reflex

Answer 4

VIII (afferent); III, IV, VI (efferent)

Question 5

CN involved in corneal reflex

Answer 5

V1 (afferent); VII (efferent)

Question 6

CN involved in gag reflex

Answer 6

IX (afferent), X/XI (efferent)

Question 7

CSF findings of bacterial meningitis (cells, protein, glucose, other)

Answer 7

♣ Cells = polymorphs
♣ Protein = high
♣ Glucose = low
♣ Other = culture and gram stain may be positive

Question 8

CSF findings of viral meningitis (cells, protein, glucose, other)

Answer 8

♣ Cells = lymphocytes
♣ Protein = high
♣ Glucose = Normal
♣ Other = Viral PCR may be positive

Question 9

CSF findings of TB meningitis

Answer 9

♣ Cells = lymphocytes
♣ Protein = high
♣ Glucose = very low
♣ Other = positive for acid-fast bacilli

Question 10

CSF findings of Guillain-Barre

Answer 10

♣ Cells = none
♣ Protein = high
♣ Glucose = normal

Question 11

CSF findings of MS

Answer 11

♣ Cells = Few lymphocytes
♣ Protein = slightly high
♣ Glucose = normal
♣ Other = oligoclonal bands usually present

Question 12

CSF findings of Acute disseminated encephalomyelitis

Answer 12

♣ Ells = Lymphocytes or polymorphs
♣ Protein = usually high
♣ Glucose = normal
♣ Other = oligoclonal bands usually absent

Question 13

CSF findings of SAH

Answer 13

♣ Cells = lymphocytes and many RBCs
♣ Protein = may be high
♣ Glucose = normal
♣ Other = Xanthochromia

Question 14

Structural causes of depressed consciousness

Answer 14

Indicated by presence of focal signs

o	Acute ischemic stroke
♣	Brainstem
♣	Unilateral cerebral hemisphere (with edema)
o	Acute intracranial hemorrhage
♣	Intraparenchymal
♣	Subdural
♣	Epidural
o	Brain tumor (with edema or hemorrhage)
♣	Primary 
♣	Metastatic
o	Brain abscess

Question 15

Diffuse cuases of depressed consiousness

Answer 15

Indicated by absence of focal signs

o Metabolic
♣ Electrolyte abnormality
• Hyponatremia, hypernatremia, hypocalcemia, hypercalcemia, hypomagnesemia, hypermagnesemia, hypophosphatemia
♣ Glucose abnormality
o Hypoglycemia, nonketotic hyperosmolar coma, diabeteic ketoacidosis
♣ Hepatic failure, uremia, thyroid dysfnction, adrenal insufficiency
o Toxic
♣ Alcohol, sedatives, narcotics, psychotropic drugs
♣ Other exogenous toxins (CO, heavy metals)
o Infectious
♣ Meningitis
♣ Diffuse encephalitis
o Hypoxic-ischemic
♣ Respiratory failure
♣ Cardiac arrest
o Others
♣ Subarachnoid hemorrhage
♣ Carcinomatous meningitis
♣ Seizures or postictal state

Question 16

What should you always do before LP in a patient with decreased consciousness

Answer 16

CT head - to avoid precipitating brain herniation if a large intracranial mass is present

Question 17

Next step in management of coma patient with focal signs

Answer 17

Urgent head CT imaging - looking for signs of stroke, hemorrhage, or mass lesion

Question 18

Next step in managment of coma patient without focal signs

Answer 18

Extensive workup for metabolic, toxic, or infectious cause

Question 19

Name 3 non-surgical ways to lower ICP

Answer 19

Elevate head
Hyperventilation
Mannitol (osmotic diuretic)

Question 20

What is the difference between Wernicke encephalopathy and Korsakoff syndrome

Answer 20

Wernicke encephalopathy
o Triad: confusion, ophthalmoplegia, ataxia
o Reversible with Thiamine administration

Korsakoff syndrome:
o Confabulation, personality change, memory loss (permanent)

Question 21

Describe vision with defect at optic nerve

Answer 21

Single eye blindness (anopia)

Question 22

Describe vision with defect at optic chiasm

Answer 22

Bitemporal hemianopia (no vision in temporal fields)

Question 23

Describe vision with defect at optic tract

Answer 23

Homonymous hemianopia (loss of vision on either R or L side)

Question 24

Describe vision with defect at temporal optic radiation (Meyer’s loop)

Answer 24

Homonymous superior quadrantanopia (Pie in the sky)

Question 25

Describe vision with defect at parietal optic radiation

Answer 25

Homonymous inferior quadrantanopia (pie on the floor)

Question 26

Describe vision with defect at occipital cortex

Answer 26

Homonymous hemianopia with macular sparing

Question 27

Describe sympathetic pathway to the pupil

Answer 27

o 1st order neuron: starts in ipsilateral hypothalamus and projects down the brainstem to the intermediolateral cell column at C8-T1 spinal level
o 2nd order neuron: travels from spinal cord via anterior horn / ventral root to the superior cervical ganglion
o 3rd order neuron: passes frpm superior cervical ganglion via carotid artery surface, through the cavernous sinus. In the cavernous sinus the fibers briefly join CN VI and then enter the orbit through the superior orbital fissure along with the ophthalmic branch (V1) of trigeminal nerve CN V via the long ciliary nerves. The long ciliary nerves then innervate the iris dilator and the Muller muscle, along with the blood vessels of the eye

Question 28

Describe parasympathetic pathway to the pupil

Answer 28

o Initial pupillary reaction: retina -> optic nerve -> chiasm -> optic track, which then synapses with the pretectal midbrain nucleus
o Interneurons send signal from pretectal nucleus to bilateral Edinger-Westphal nucleus, situated in the rostral aspect of the third nerve nucleus
o Efferent parasympathetic fibers from the EWN travel with CN III. In the cavernous sinus they run with CN III and ultimately synapse in the ciliary ganglion located in the posterior orbit
o Parasympathetic fibers then innervate the pupilloconstrictor msucle

Question 29

Effects of cocaine eye drops in Horner’s

Answer 29

Cocaine eye drops fail to dilate the abnormal pupil

Question 30

Causes of 1st order neuron Horners

Answer 30

♣ Hypothalamic infarcts, tumor
♣ Mesencephalic stroke
♣ Brainstem: ischemia, tuor, hemorrhage
♣ Spinal cord: syringomyelia, trauma

Question 31

Causes of 2nd order neuron Horner’s

Answer 31

♣ Cervicothoracic cord/spinal root trauma
♣ Cervical spondylosis
♣ Pulmonary apical tumor: Pancoast tumor

Question 32

Causes of 3rd order neuron Horners

Answer 32

♣ Superior cervical ganglion (tumor, iatrogenic)
♣ Internal carotid arter: dissection, trauma, thrombosis, tumor
♣ Base of skull: tumor, trauma
Cavernous sinus: tumor, inflammation, aneurysm, thrombosis, fistula

Question 33

Describe progression of sx in CN III palsy due to compression

Answer 33

Because parasympathetic fibers run in outer part of nerve and motor fibers are more internal, compressino of the nerve initially produces a dilated pupil (mydriasis) without compromising eye movements

Question 34

Describe progression of sx in CN III palsy due to vascular problems

Answer 34

Will produce pupil-sparing IIIrd nerve lesion in which pupil is normal but there is palsy of the ocular muscles

Question 35

What direction will eye point with dysfunction of CN III

Answer 35

down and out

Question 36

What is the function of MLF

Answer 36

Connects the contralateral abducens nucleus and paramedian pontine reticular formation (PPRF) with ipsilateral IIIrd nerve nucleus

Question 37

Describe one and a half syndrome

Answer 37

♣ Lesion affects ipsilateral PPRF or CN VI and ipsilateral MLF
♣ Ipsilateral conjugate horizontal gaze palsy (“one”) + ipsilateral INO (“half”)
♣ Only remaiing horizontal movement is contralateral abduction (cannot look ipsilaterally on either eye)
♣ Failure of medial recturs to move synchronously with contralateral lateral rectus
♣ Abducting eye will then have nystagmus back to midline

Question 38

Describe sx of INO

Answer 38

♣ Failure of medial rectus to move synchronously with contralateral lateral rectus
♣ Abducting eye will then have nystagmus back to midline
Adduction during conversion is spared

Question 39

Describe pathway of voluntary eye movement

Answer 39

o Frontal eye fields (R) located around lateral part of precentral sulcus
o Descends ipsilaterally until crossing midline late in pons to project to contralateral (L) paramedian pontine reticular formation (PPRF)
o The contralateral (L) PPRF sends projections to:
♣ Contralateral (L) abducens nucleus (CN VI)
♣ Crossing back to R early in pons and up R medial longitudinal fasciculus to R oculomotor nucleus (CN III)

Question 40

How do you diagnose Parkinsons

Answer 40

Clinical diagnosis based on physical exam (resting tremor, rigidity, bradykinesia, postural instability)

Question 41

What is one of the earliest and most unique sx of Parkinsons

Answer 41

Loss of smell

Question 42

Draw out brachial plexus

Answer 42

DO IT!