Neuro Flashcards
What do the 12 cranial nerves do?
Mediate complex motor and sensory functions
Cranial nerves I and II
Fiber tracks emerging from the brain.
Cranial nerve III-VII
Arise from the diencephalon and brain stem.
Cranial nerve I
Olfactory: sense of smell
Cranial nerve II
Optic: vision
Cranial nerve III
Oculomotor: pupillary constriction, opening of the eye lid and most extra ocular movements.
Cranial nerve IV
Trochlear: downward and internal rotation of the eye
Cranial nerve V: motor
Trigeminal: motor: temporal and masseter muscles. lateral pterygoids (lateral jaw movements
Cranial nerve V: sensory
facial: ophthalmic, maxillary, mandibular
Cranial nerve VI:
abducens: lateral deviation of the eye
Cranial nerve VII: motor
Facial: facial movements and expression, closing the eye, closing the mouth
Cranial nerve VII: sensory
facial: taste for salty, sweet, sour, bitter on anterior 2/3 of tongue and sensation in the ear
Cranial nerve VIII
acoustic: hearing (cochlear) and balance (vestibular)
Cranial nerve IX: motor
glossopharyngeal: pharynx
Cranial nerve IX: sensory
glossopharyngeal: posterior portions of the eardrum and ear canal, pharynx, posterior tongue and taste
Cranial nerve X
vagus: palate, pharynx, larynx
Cranial nerve XI
spinal accessory: sternocleidomastoid and upper portion of trapezius
Cranial nerve XII
hypoglossal: tongue
Common symptoms to assess in health history
headache
dizziness
numbness
weakness
loss of sensation
syncope
seizures
tremors
involuntary movements
appearance
behavior
mood
memory
speech
orientation
How to assess cranial nerve I
close each nostril and have them state what they are smelling
How to assess cranial nerve II
visual acuity (reading)
visual fields (fingers to peripheral)
inspect the optic fungi (arteries/veins 1/3) any vascular narrowing, papillaredema, pallor (optic atrophy), cup enlargement (glaucoma)
How to assess cranial nerves III, IV, VI
- occular movements:
6 cardinal directions - cover/uncover
convergence (look at finger as you bring it close to nose - nystagmus (focus on distant object)
- ptosis: dropping of upper lids
- palpate temporal and masseter muscles: ask them to clinch teeth, move jaw side to side
- pain: sharp vs dull touching points while eyes closed
- light touch with cotton wisp
- corneal reflex: remove contacts, with cotton wisp, lightly touch cornea
6 cardinal directions of gaze
conjugate movements, any diplopia
worse on one side?
convergence
nystagmus
Diplopia
double vision
Nystagmus
involuntary jerking of the eyes: horizontal, vertical, rotary, mixed; direction
What could be a cause for ptosis
palsy of cranial nerve III and myasthenia gravis
What is myastenia gravis?
long-term neuromuscular junction disease that leads to varying degrees of skeletal muscle weakness: most commonly affecting the eyes, face, and swallowing. Can cause double vision, dropping eyelids, trouble talking, trouble walking. Those affected often have a large Thymus.
How to assess cranial nerve VII
- inspect patients face at rest and during conversation
- show teeth
- close eyes very tightly
- wrinkle forehead
- puff out cheeks
- tense neck muscles
not symmetry and any involuntary movements.
How to assess cranial nerve VIII
- whispered voice test
- webber test for
- Renee test
What is the webber test?
screening test for hearing using tuning fork to detect unilateral conductive hearing loss and unilateral sensorineural loss
place tuning fork in middle of forehead, is it the same in both ears
What is the Rinne test?
vibrating tuning fork placed on the mastoid process behind each ear until they no longer can hear it, then place it in front of the ear
A normal or positive result if the patient can still hear the tuning fork when moved in front of the ear.
How to assess cranial nerve IX and X?
- Say “ah” for yawn observe the soft palate in pharynx.
it should rise promptly, symmetrically, and uvula should remain midline - gag reflex
How to assess the cranial nerve XI?
- from behind ask the patient to shrug his shoulders upward against your hands
evaluate strength and contraction of trapezius muscles. - from in front of the patient “turn head to each side against your hand”
observe contraction of opposite sternomastoid muscle.