3 - Neuro Exam and Testing Flashcards
Cranial nerve I
Olfactory (I)
Sensory: smell
Cranial nerve II
Optic (II)
Sensory: visual acuity, visual fields
Parasympathetic: pupillary constriction, lens shape change
Cranial nerve III
Oculomotor (III)
Motor: raises eyelids, most oculomotor movements
Cranial nerve IV
Trochlear (IV)
Motor: downward, inward movement of the eye
Cranial nerve V
Trigeminal (V)
Motor: jaw opening and closing, chewing
Cranial nerve VI
Abducens (VI)
Motor: lateral eye movement
Cranial nerve VII
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
Cranial nerve VIII
Vestibulocochlear (VIII)
Sensory: hearing and equilibrium
Cranial nerve IX
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
Cranial nerve X
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
Cranial nerve XI
Spinal Accessory (XI)
Motor: turn head, shrug shoulders, some actions of phonation
Cranial nerve XII
Hypoglossal (XII)
Motor: tongue movement for speech and swallowing
What is anosmia?
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”
What is aniscoria?
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.
What is miosis?
Pupil constriction
Parasympathetic stimulation, light, looking at a near object
What is mydriasis?
Pupil dilation
Sympathetic stimulation, decrease in light, looking at a far object
What is the direct pupullary reaction to light?
Light shown on the retina (afferent CN II) results in constriction of the ipsilateral pupil (efferent CN III)
What is the indirect pupillary reaction to light?
Light shown on the retina (afferent CN II) results in constriction of the contralateral pupil (efferent CN III)
What is pupillary reaction to accomodation?
Pupils constrict when focused on a near object
What is a Marcus Gunn pupil?
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)
What is an Argyll Roberson pupil?
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
What is Horner’s syndrome?
AKA oculosympathetic paresis
- Loss of sympathetic tone…
- Ptosis (droopy eyelid)
- Miosis (pupils constricted)
- Anhydrosis (lack of sweating on that side of the face)
What is the DDx for Horner’s syndrome?
- Carotid artery dissection
- Pancoast tumor
- Nasopharyngeal tumor
- Brachial plexus injury
- Cavernous sinus thrombosis
- Fibromuscular dysplasia
What is CN IV palsy?
- 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
What is saccades?
Normal jumping movements of the eye with voluntary scanning (reading, etc)
What is nystagmus?
- 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
What are the two types of nystagmus we will focus on?
- Cerebellar = lateral, fast phase towards the side of the lesion
- Vertical = typically indicates a lesion in the midbrain
What suggests an upper motor neuron lesion in the face?
- 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
What suggests a lower motor neuron lesion (i.e. Bells Palsy) will cause facial drooping involving the forehead?
A patient with an LMN lesion (eg Bells Palsy) will cause facial drooping involving the forehead
What is conductive hearing loss?
- 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
What is a sensorineural hearing loss?
- Damage to the inner ear apparatus or CN VIII
- Ex: med toxicity, genetic hearing loss, aging, trauma, infection, exposure to loud noises
What do you use to perform a Weber and a Rinne test?
Both performed with 512 hz tuning fork
What is a Rinne test?
- 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
What is a Weber test?
- 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
What are the frequently tested dermatomes?
- 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
What is stereognosis?
- Identification of objects (e.g. key, clothespin, spoon) by touch
- Inability to identify objects by touch is Tactile agnosia
- Parietal lobe function
What is graphesthesia?
- Write a letter/number on patients palm
What is tactile agnosia again?
Inability to identify objects by touch is Tactile agnosia
What is a two-point discrimination?
The patient’s ability to distinguish two points being touched rather than 1
What is the progression of most sensitive to least sensitive areas for two-point discrimination?
- Tongue
- Lips
- Fingertips
- Dorsum of fingers
- Palm
- Back of hand
- Dorsum of foot
What does a lack of two point discrimination ability indicate?
Loss of TPD with maintenance of other sensory function may indicate parietal lobe injury!
What are the “main points” of sensory testing (what he actually does)?
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.
What deep tendon reflexes do we test?
- Biceps
- Brachioradial
- Triceps
- Patellar
- Achilles
What spinal levels are we testing with each of the tendon reflexes?
- Biceps (C5 and C6)
- Brachioradial (C5 and C6)
- Triceps (C6, C7***, C8)
- Patellar (L2, L3, L4)
- Achilles (S1*** and S2)
*** were bold
How do we score deep tendon reflex?
0 - No response 1+ - Sluggish/diminished 2+ - Active or expected 3+ - Brisker than expected 4+ - Brisk/hyperactive, transient clonus
How do we score muscle strength testing?
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”
What do you need to remember for motor function testing?
- 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!
