3 - Neuro Exam and Testing

Question 1

Cranial nerve I

Answer 1

Olfactory (I)

Sensory: smell

Question 2

Cranial nerve II

Answer 2

Optic (II)

Sensory: visual acuity, visual fields
Parasympathetic: pupillary constriction, lens shape change

Question 3

Cranial nerve III

Answer 3

Oculomotor (III)

Motor: raises eyelids, most oculomotor movements

Question 4

Cranial nerve IV

Answer 4

Trochlear (IV)

Motor: downward, inward movement of the eye

Question 5

Cranial nerve V

Answer 5

Trigeminal (V)

Motor: jaw opening and closing, chewing

Question 6

Cranial nerve VI

Answer 6

Abducens (VI)

Motor: lateral eye movement

Question 7

Cranial nerve VII

Answer 7

Facial (VII)

Motor: movement of facial expression (except jaw), close eyelids, labial speech sounds
Sensory: pharynx, taste anterior 2/3 of tongue
Parasympathetic: secretion of tears and saliva

Question 8

Cranial nerve VIII

Answer 8

Vestibulocochlear (VIII)

Sensory: hearing and equilibrium

Question 9

Cranial nerve IX

Answer 9

Glossopharyngeal (IX)

Motor: Voluntary muscles for swallowing and phonation
Sensory: sensation of nasopharynx, gag reflex, taste posterior 1/3 of tongue
Parasympathetic: secretion of saliva, carotid reflex

Question 10

Cranial nerve X

Answer 10

Vagus (X)

Sensory: behind the ear, part of external ear canal
Parasympathetic: Secretion of digestive enzymes, carotid reflex, involuntary action of the heart, lungs, digestive tract

Question 11

Cranial nerve XI

Answer 11

Spinal Accessory (XI)

Motor: turn head, shrug shoulders, some actions of phonation

Question 12

Cranial nerve XII

Answer 12

Hypoglossal (XII)

Motor: tongue movement for speech and swallowing

Question 13

What is anosmia?

Answer 13

Loss of sense of smell

Test using whatever is on hand (i.e. hand sanitizer)

Document as “CN I is grossly intact, detects hand sanitizer”

Question 14

What is aniscoria?

Answer 14

Pupil asymmetry, present in up to 20% of the population.

If the difference is consistent in varying levels of ambient light, it’s probably normal.

Question 15

What is miosis?

Answer 15

Pupil constriction

Parasympathetic stimulation, light, looking at a near object

Question 16

What is mydriasis?

Answer 16

Pupil dilation

Sympathetic stimulation, decrease in light, looking at a far object

Question 17

What is the direct pupullary reaction to light?

Answer 17

Light shown on the retina (afferent CN II) results in constriction of the ipsilateral pupil (efferent CN III)

Question 18

What is the indirect pupillary reaction to light?

Answer 18

Light shown on the retina (afferent CN II) results in constriction of the contralateral pupil (efferent CN III)

Question 19

What is pupillary reaction to accomodation?

Answer 19

Pupils constrict when focused on a near object

Question 20

What is a Marcus Gunn pupil?

Answer 20

AKA relative afferent pupillary defect

• Due to optic nerve or severe retinal disease
• Direct pupillary response to light is absent, but the indirect response is intact because CN III remains intact
• DDx includes:
  
  • -> Optic neuritis
  • -> Severe glaucoma
  • -> Retinal detachment
  • -> Retinal infection (CMV, herpes)

Question 21

What is an Argyll Roberson pupil?

Answer 21

Intact to accomodation but not to light

• AKA Prostitute’s pupil
• Hallmark of neurosyphilis
• Pupils typically small at baseline, nonresponsive to light but do constrict when looking at a near object

Question 22

What is Horner’s syndrome?

Answer 22

AKA oculosympathetic paresis

• Loss of sympathetic tone…
• Ptosis (droopy eyelid)
• Miosis (pupils constricted)
• Anhydrosis (lack of sweating on that side of the face)

Question 23

What is the DDx for Horner’s syndrome?

Answer 23

• Carotid artery dissection
• Pancoast tumor
• Nasopharyngeal tumor
• Brachial plexus injury
• Cavernous sinus thrombosis
• Fibromuscular dysplasia

Question 24

What is CN IV palsy?

Answer 24

• Inability to bring the eye in and down
• Often leads to vertical diplopia with reading or near vision
• Often develop head tilt AWAY from the affected eye

Question 25

What is saccades?

Answer 25

Normal jumping movements of the eye with voluntary scanning (reading, etc)

Question 26

What is nystagmus?

Answer 26

- Slow drift away from the focus with fast beat correction back to the focus - Named for the fast phase (NOT named for the slow drift!) - 13 subtypes described in DeGowin! Let’s just talk about 2

Question 27

What are the two types of nystagmus we will focus on?

Answer 27

- Cerebellar = lateral, fast phase towards the side of the lesion - Vertical = typically indicates a lesion in the midbrain

Question 28

What suggests an upper motor neuron lesion in the face?

Answer 28

- The forehead has bilateral UMN involvement but unilateral LMN involvement - This means that an UMN lesion (eg stroke) will cause facial drooping but spare the forehead

Question 29

What suggests a lower motor neuron lesion (i.e. Bells Palsy) will cause facial drooping involving the forehead?

Answer 29

A patient with an LMN lesion (eg Bells Palsy) will cause facial drooping involving the forehead

Question 30

What is conductive hearing loss?

Answer 30

- Hearing loss is due to inefficient conduction from the outer ear to the ear drum to the ossicles - Ex: fluid in the middle ear, perforated ear drum, impacted cerumen, foreign body

Question 31

What is a sensorineural hearing loss?

Answer 31

- Damage to the inner ear apparatus or CN VIII | - Ex: med toxicity, genetic hearing loss, aging, trauma, infection, exposure to loud noises

Question 32

What do you use to perform a Weber and a Rinne test?

Answer 32

Both performed with 512 hz tuning fork

Question 33

What is a Rinne test?

Answer 33

- Vibrating handle of the tuning fork against the mastoid process until the sound fades, then move the tines to just outside the auditory meatus - The sound should be LOUDER on air conduction than bone conduction - A normal Rinne test is POSITIVE - An abnormal Rinne test is NEGATIVE

Question 34

What is a Weber test?

Answer 34

- Vibrating handle of the tuning fork against midline of the skull - The sound should be equal in both ears - Louder in one ear is considered Lateralising to that side

Question 35

What are the frequently tested dermatomes?

Answer 35

- C2: back of the head - C4: nipple line - T1: anterior axilla - C6: thumb - C7: index and middle finger - C8: ring and little fingers - T10: umbilicus - L3: medial knee - L4: medial malleolus - L5 : Dorsum 3rd MTP Joint - S1:Lateral Heel - S2: Popliteal Fossa - S3: Ischial Tuberosity - S5: Perianal Area These should be pretty close, but not always exact

Question 36

What is stereognosis?

Answer 36

- Identification of objects (e.g. key, clothespin, spoon) by touch - Inability to identify objects by touch is Tactile agnosia - Parietal lobe function

Question 37

What is graphesthesia?

Answer 37

- Write a letter/number on patients palm

Question 38

What is tactile agnosia again?

Answer 38

Inability to identify objects by touch is Tactile agnosia

Question 39

What is a two-point discrimination?

Answer 39

The patient's ability to distinguish two points being touched rather than 1

Question 40

What is the progression of most sensitive to least sensitive areas for two-point discrimination?

Answer 40

- Tongue - Lips - Fingertips - Dorsum of fingers - Palm - Back of hand - Dorsum of foot

Question 41

What does a lack of two point discrimination ability indicate?

Answer 41

Loss of TPD with maintenance of other sensory function may indicate parietal lobe injury!

Question 42

What are the "main points" of sensory testing (what he actually does)?

Answer 42

No stars, but said "I should probably have stars up there" - Light touch (+/- pin prick): shoulders, inner/outer arm and forearm; 1st, 3rd, 5th fingers; knee cap; inner/outer lower leg; monofilament of feet - “sensation grossly intact” (I will detail this further if patient has abnormal findings or a neuro complaint) - Further evaluation is based on initial findings. - I do temperature/vibration/proprioception only rarely. - Confession: I have never performed stereognosis or graphesthesia except out of academic interest in known stroke patients. - I have a low threshold to check for saddle anesthesia, urinary retention, and rectal tone.

Question 43

What deep tendon reflexes do we test?

Answer 43

- Biceps - Brachioradial - Triceps - Patellar - Achilles

Question 44

What spinal levels are we testing with each of the tendon reflexes?

Answer 44

- Biceps (C5 and C6) - Brachioradial (C5 and C6) - Triceps (C6, C7***, C8) - Patellar (L2, L3, L4) - Achilles (S1*** and S2) *** were bold

Question 45

How do we score deep tendon reflex?

Answer 45

``` 0 - No response 1+ - Sluggish/diminished 2+ - Active or expected 3+ - Brisker than expected 4+ - Brisk/hyperactive, transient clonus ```

Question 46

How do we score muscle strength testing? ***

Answer 46

``` 0 - No evidence of movement 1 - Trace movement 2 - Full ROM without gravity 3 - Full ROM against gravity 4 - Full ROM against gravity with some resistance 5 - “Normal” ```

Question 47

What do you need to remember for motor function testing?

Answer 47

- For my lecture purposes, I don’t need you to memorize all of the muscle innervations. - Know that upper extremity weakness is due to damage in the C-Spine or higher. - Know that Lower extremity weakness is due to damage in the L-spine/Sacrum or higher. - If the patient is having changes in bowel or bladder function or weakness to the point they can no longer ambulate, they need urgent evaluation by somebody else!