The Clinical Neurological Exam Flashcards
what are upper motor neurons?
- descending axons from cortex to brainstem to SC
- brain, SC
what are lower motor neurons?
- axons exiting the CNS and innervating peripheral targets
- motor divisions of cranial nerves
signs of UMN lesions
- weakness
- increased reflexes
- increased tone
signs of LMN lesions
- weakness
- atrophy
- fasciculations
- decreased reflexes
- decreased tone
tests for olfactory nerve (CN I)
- tests for discrimination (contrast odorants)
- tests for arousal (noxious stimulant)
if CN I is impaired, this is called…
anosmia (loss of smell)
tests for optic nerve (CN II)
- visual acuity
- visual field cuts
- pupillary response to light accommodation (II, III)
- accommodation (II, III)
- color discrimination
what CNs are tested by the big H test?
oculomotor (III), trochlear (IV), abducens (VI)
if your pt has a dysconjugate gaze in both eyes in the same direction, is this an UMN or LMN lesion?
UMN
if your pt has a dysconjugate gaze in one eye in a specific direction, is this an UMN or LMN lesion?
LMN
tests for trigeminal nerve (CN V)
- light touch and sharp/dull to face (V1, V2, V3)
- bite strength
tests for motor division of facial nerve (CN VII)
smile, raise your eyebrows, puff out cheeks, purse your lips, close your eyes tightly
tests for sensory division of facial nerve (CN VII)
- taste (don’t typically test this)
- secretomotor function
corneal reflex test includes what 2 CNs?
V and VII
how to differentiate UMN and LMN facial weakness
- UMN: forehead is not affected
- LMN: forehead is affected
tests for vestibulocochlear nerve (CN VIII)
- Weber and Rinne tests
- these tests identify auditory loss and differentiate b/w conductive and sensorineural hearing loss
tests for glossopharyngeal nerve (CN IX)
- palatal activation
- look for symmetry
- involved side will fail to rise
how to differentiate UMN and LMN lesion when testing CN IX
- UMN: uvula will deviate towards involved side
- LMN: uvula will deviate away from involved side
gag reflex test includes what 2 CNs?
- sensory (afferent) limb: CN IX
- motor (efferent) limb: CN X
voice hoarseness could indicate problems with what CNs?
IX and X
tests for spinal accessory nerve (CN XI)
- shoulder shrug (upper trap)
- side bend and rotate (SCM)
how to differentiate UMN and LMN lesion when testing CN XI
- UMN: contralateral trap weakness, can see sparing of SCM
- LMN: ipsilateral, impacts both
tests for hypoglossal nerve (CN XII)
stick out tongue
how to differentiate UMN and LMN lesion when testing CN XII
- UMN: tongue will deviate away from involved side
- LMN: tongue will deviate towards involved side, will also see atrophy and fasciculations
