Neuro Chapter 15

Front 1

normal pupillary light reflex

Back 1

elicited by shining light into one eye causing its pupil to constrict (direct response) and that of the other eye (consensual response).
Involves retinal ganglion cells projecting to pretectal area (rostral to superior colliculus), which then projects bilaterally to Edinger-Westphal nucleus of CN III.

Front 2

left optic nerve lesion

Back 2

both pupils constrict when light is shined in right eye, but neither constricts when light shined in left eye

Front 3

right cranial nerve III lesion

Back 3

left pupil constricts when light shined in either eye, right pupil fails to constrict when light shined in either eye

Front 4

relative afferent pupillary defect

Back 4

both pupils initially constrict, after moving flashlight from normal to affected eye, pupillary dilation occurs due to reduced afferent input resulting from optic nerve lesion

Front 5

near reflex

Back 5

occurs when viewing a nearby object; pupillary constriction, lens accomodation (thickens), and convergence of the eyes (adduction)

Front 6

dissociation of light and near reflexes

Back 6

Pupillary constriction occurs with the near reflex, but the light reflex is absent due to selective disruption of pupillary light reflex pathway at superior colliculus or pretectal area.
Due to neurosyphilis (Argyll Robertson pupil), Parinaud's syndrome (pineal tumor compressing the dorsal midbrain, also impairing upward gaze)

Front 7

Horner's syndrome

Back 7

from a lesion of the cervical sympathetic nerves (pupillodilators), a three neuron circuit.
Signs = miosis (constricted pupil), anhidrosis (absence of sweating ipsilateral face), mild ptosis (paralysis of superior tarsal muscle, typically partial or mild).

Front 8

nystagmus

Back 8

repetitive, oscillatory, jerky eye movements due to imbalance of vestibular or brain stem control of eye movement.
Horizontal nystagmus from a vestibular lesion consists of a slow component toward the side of the lesion, and a fast component in the other direction.

Front 9

monocular diplopia

Back 9

seeing double with one eye closed; caused by ocular disorder (dislocated lens or detached retina) or psychiatric disorder, NOT neurological disease

Front 10

binocular diplopia

Back 10

seeing double with both eyes open, seeing normally with either eye closed.
Caused by lesions of the brain stem (CN III,IV,or VI, cerebellum or extraocular muscles)

Front 11

internuclear ophthalmoplegia (medial longitudinal fasciculus, MLF syndrome)

Back 11

inability of adducting eye to pass the midline on the side of the lesion, nystagmus of abducting eye, intact convergence.
Typical of MS in younger patients, ischemic infarction in older patients.

Front 12

trigeminal, upper motor neuron lesion

Back 12

bilateral weakness of muscles of mastication, with a hyperactive jaw jerk

Front 13

trigeminal, lower motor neuron lesion

Back 13

jaw deviates to one side of the lesion where the masseter muscle is atrophic

Front 14

superior orbital fissure syndrome and lesion of the cavernous venous sinus

Back 14

sensory loss in ophthalmic division of CN V, plus paresis of CN III,IV,and VI

Front 15

trigeminal neuralgia

Back 15

episodic, lightninglike jabs of pain, usually in maxillary or mandibular branches of CN V due to tortuous blood vessels or MS lesions.
Treated with carbamazepine.

Front 16

facial, upper motor neuron lesion

Back 16

lesion involving the motor cortex and its corticobulbar tract controlling CN VII, which causes only paralyis of lower 2/3 of the contralateral face, forehead moves normally

Front 17

facial, lower motor neuron lesion

Back 17

nuclear and peripheral (infranuclear) lesions of CN VII cause paralysis of entire ipsilateral half of the face

Front 18

facial, lower motor neuron lesion near the stylomastoid foramen

Back 18

paralysis of all ipsilateral facial muscles

Front 19

facial, lower motor neuron lesion in the facial canal of the temporal (petrous) bone

Back 19

ipsilateral facial muscle paralysis, loss of taste over anterior two thirds of tongue if chorda tympani branch affected, hyperacusis if branch to stapedius is affected

Front 20

facial, lower motor neuron lesion in cerebellopontine angle of posterior fossa

Back 20

often caused by acoustic neuroma (tumor of CN VIII), paralysis of ipsilateral facial muscles, loss of taste, deafness and tinnitus

Front 21

facial, lower motor neuron lesion of pontine

Back 21

paralysis of ipsilateral facial muscles, ipsilateral weakness of lateral gaze from involvement of PPRF and adjacent CN VI

Front 22

Bell's palsy

Back 22

sudden, non-traumatic onset of isolated peripheral CN VII palsy. Due to inflammation of facial nerve w/in petrous bone from possible viral infection. Tx w/corticosteroid.

Front 23

lesions to glossopharyngeal and vagus nerves

Back 23

clinically difficult to test seperately, impaired speech and swallowing. ipsilateral drooping of palatal arch, uvula points to normal side. gag reflex decreased, hoarseness.

Front 24

spinal accessory nerve lesion

Back 24

causes weakness of ipsilateral sternocleidomastoid and trapezius muscles

Front 25

hypoglossal nerve lesion

Back 25

UMN-few pts w/protruded tongue deviating away from the involved cerebral hemisphere
LMN-weakness in ipsilateral tongue, deviation to side of lesion, atrophy, fasciculations, and fibrillations ipsilaterally

Front 26

crossed brain stem disorders

Back 26

corticospinal decussates in lower medulla;lesion of brain stem may cause ipsilateral cranial nerve deficit and a contralateral limb weakness of UMN type
spinothalamic decussates in spinal cord; lesion in medulla can cause pain and temp deficit of contralateral body, with pain and temp deficit of ipsilateral face

Front 27

medial midbrain syndrome (Weber syndrome)

Back 27

caused by occlusion of a branch of the posterior cerebral artery, ipsilateral CN III lesion and contralateral hemiplegia (cerebral peduncle involved)

Front 28

lateral medullary syndrome (Wallenberg syndrome)

Back 28

caused by occlusion of the vertebral or posterior inferior cerebellar artery (PICA).