The Clinical Neurological Exam

Question 1

what are upper motor neurons?

Answer 1

• descending axons from cortex to brainstem to SC

- brain, SC

Question 2

what are lower motor neurons?

Answer 2

• axons exiting the CNS and innervating peripheral targets

- motor divisions of cranial nerves

Question 3

signs of UMN lesions

Answer 3

• weakness
• increased reflexes
• increased tone

Question 4

signs of LMN lesions

Answer 4

• weakness
• atrophy
• fasciculations
• decreased reflexes
• decreased tone

Question 5

tests for olfactory nerve (CN I)

Answer 5

• tests for discrimination (contrast odorants)

- tests for arousal (noxious stimulant)

Question 6

if CN I is impaired, this is called…

Answer 6

anosmia (loss of smell)

Question 7

tests for optic nerve (CN II)

Answer 7

• visual acuity
• visual field cuts
• pupillary response to light accommodation (II, III)
• accommodation (II, III)
• color discrimination

Question 8

what CNs are tested by the big H test?

Answer 8

oculomotor (III), trochlear (IV), abducens (VI)

Question 9

if your pt has a dysconjugate gaze in both eyes in the same direction, is this an UMN or LMN lesion?

Answer 9

UMN

Question 10

if your pt has a dysconjugate gaze in one eye in a specific direction, is this an UMN or LMN lesion?

Answer 10

LMN

Question 11

tests for trigeminal nerve (CN V)

Answer 11

• light touch and sharp/dull to face (V1, V2, V3)

- bite strength

Question 12

tests for motor division of facial nerve (CN VII)

Answer 12

smile, raise your eyebrows, puff out cheeks, purse your lips, close your eyes tightly

Question 13

tests for sensory division of facial nerve (CN VII)

Answer 13

• taste (don’t typically test this)

- secretomotor function

Question 14

corneal reflex test includes what 2 CNs?

Answer 14

V and VII

Question 15

how to differentiate UMN and LMN facial weakness

Answer 15

• UMN: forehead is not affected

- LMN: forehead is affected

Question 16

tests for vestibulocochlear nerve (CN VIII)

Answer 16

• Weber and Rinne tests

- these tests identify auditory loss and differentiate b/w conductive and sensorineural hearing loss

Question 17

tests for glossopharyngeal nerve (CN IX)

Answer 17

• palatal activation
• look for symmetry
• involved side will fail to rise

Question 18

how to differentiate UMN and LMN lesion when testing CN IX

Answer 18

• UMN: uvula will deviate towards involved side

- LMN: uvula will deviate away from involved side

Question 19

gag reflex test includes what 2 CNs?

Answer 19

• sensory (afferent) limb: CN IX

- motor (efferent) limb: CN X

Question 20

voice hoarseness could indicate problems with what CNs?

Answer 20

IX and X

Question 21

tests for spinal accessory nerve (CN XI)

Answer 21

• shoulder shrug (upper trap)

- side bend and rotate (SCM)

Question 22

how to differentiate UMN and LMN lesion when testing CN XI

Answer 22

• UMN: contralateral trap weakness, can see sparing of SCM

- LMN: ipsilateral, impacts both

Question 23

tests for hypoglossal nerve (CN XII)

Answer 23

stick out tongue

Question 24

how to differentiate UMN and LMN lesion when testing CN XII

Answer 24

• UMN: tongue will deviate away from involved side

- LMN: tongue will deviate towards involved side, will also see atrophy and fasciculations