neuro exam

Question 1

What is agnosia? Where is the lesion? What are examples? (4 examples)

Answer 1

defect in recognizing a complex sensory stimulus. due to lesions of association cortex.
anosognosia: denial of illness
asomatognosia: denial of half of the body
prosopagnosia: inability to recognize faces
extinction to double simulatious stim

Question 2

What is asomatognosia?

Answer 2

denial of half the body

Question 3

What is prosopagnosia?

Answer 3

inability to recognize faces

Question 4

What is apraxia? Where is the lesion? What are 4 examples?

Answer 4

defect in the performance of a complex motor tastk (“brush your teeth”)
due to lesions of the association cortex
1. ideomotor apraxia: inability to perform motor tasks on command
2. ideational apraxia: inability to plan a series of complex tasks (how would you set the table for dinner)
3. constructional apraxia: inability to copy a figure
4. dressing apraxia: inability to dress oneself

Question 5

What is the difference btw mood and affect?

Answer 5

mood: how the pt feels
affect: how the pt comes across to the examiner

Question 6

What is the significance of raccoon’s eyes or battle sign (hematoma below the ear)

Answer 6

may indicate presence of basilar skill fracture

Question 7

What is the straight leg raising test?

Answer 7

pt lies supine
flex thigh at the hip
look for pain that radiates down the involved leg in a dermatomail pattern. may be any root from L4-S2.

Question 8

What are three signs that indicate meningeal inflammation?

Answer 8

meningismus: pain with neck flexion only
also Brudzinski sign: sponateous flexion of the legs at the hips and knees, following neck flexion
Kernig sign: resistance to knee extension when the hips are flexed

Question 9

How do you check for visual neglect?

Answer 9

pt keeps both eyes open and looks at dr’s nose. dr presents bilateral simulatenous stimuli and the pt is aksed to localize the simuli. neglct often implies parietal lobe lesions

Question 10

What are three terms for abnormal pupils that I might use? (small, big, uneven)

Answer 10

miotic: small pupil
mydriotic: big pupil
anisocoric: uneven pupils

Question 11

Marcus-Gunn pupil. lesion, presentation

Answer 11

CNII lesion

deafferented pupl. constricts to consensual but not direct light. no anisocoria

Question 12

Hutchinson pupil. lesion, presentation

Answer 12

lesion: CNIII

dilated pupl that does not respond to direct or consensual light. anisocria present.

Question 13

Horner’s syndrome. lesion, presentation

Answer 13

sympathetic lesion. see a small pupil with associated ipsilateral ptosis and decreased facial sweating. anisocoria is present

Question 14

Adie’s tonic pupil. lesion, presentation

Answer 14

parasympathetic lesion. anisocoria is present. you see a dilated pupil with an imparied light response and slow constriction to near vision

Question 15

Argyll Robetson pupil lesion, presentation

Answer 15

small irregular pupil that constricts to near vision but not to light. lesion in the pretectum. Sign of neurosyphilis.

Question 16

Describe the vestibulo-ocular reflex.

Answer 16

fixates image on the retina wrt head and neck motion. head motion is angular rotation: stimulates the semicircular canals in the inner ear. convey this to vestibular nuclei in the brain stem via CN VIII. the vestibular nuclei project to CN III, IV, VI vial the MLF

Question 17

What are the important roles of the MLF?

Answer 17

critical for the vestibulo-ocular reflex and visual pursuit. also good for visual saccade and conjugate gaze

Question 18

How does visual saccade occur?

Answer 18

originates in frontal eye fields.
travels in a crossed fashion to the lateral gaze center in the pons (PPRF- paramedian pontine reticular formation), and the to CN III, IV, VI via MLF

Question 19

What motions/muscles are controlled by each cranial nerve (extraocular only)

Answer 19

CN III: most
CN IV: trochlear nerve to superior oblique. makes eye look down and in.
CN VI: abducens. innervates lateral rectus: makes eye look to the side

Question 20

What is the direction of nystagmus?

Answer 20

direction of the fast component

Question 21

What are 5 pathologic causes of nystagmus?

Answer 21

vestibular lesions, cerebellar lesions, brain stem lesions, drugs, congenital problems

Question 22

What are 4 causes of gaze palseis?

Answer 22

extraocular muscle lesions (as with hyperthyroidism)
NMJ issues (mysthenia gravis)
lesions to CN III, IV, V
lesions to the MLF that give internuclear opthalmopelgia. seen with MS in young folks and stokes with older adults

Question 23

What is a gaze preference and a potential cause?

Answer 23

paresis of gaze seen after lesions to frontal eye fields, as in a large stroke

Question 24

What muscles innervate the eyelid? Nerves? How do you distinguish between the two clinically?

Answer 24

levator palpebrae (CN III) and superior tarsal muscle (sympathetics).
If lesion is to the sympathetics, pupil will be small (aka Horner's syndrome); if lesion is to CNIII, pupil will be large.