Disorders

Question 1

Multiple Sclerosis

Answer 1

chronic demyelinating disease of the CNS

sx: paralysis due to sensory and motor axon disruption

Question 2

Guillan-Barre Syndrome

Answer 2

acute demyelinating disease of the PNS

sx: decreases senses and motor coordination

Question 3

Hyperkalemic periodic paralysis

Answer 3

episodes of weakness and low muscle tone due to inability to fire action potentials bc of incr in K+

Question 4

Myotonia

Answer 4

Cl- channel abnormality causing difficulty relaxing muscles

Question 5

Thomsen’s disease and Becker’s disease

Answer 5

channelopathy causing slow relaxation after sudden contraction

Question 6

Myasthenia gravis

Answer 6

autoimmune disease producing Abs against AchR at the NMJ causing muscle weakness
tx: AchE inhibitors

Question 7

Syringomyelia

Answer 7

damage to crossing fibers around the central canal

Question 8

Retinitis Pigmentosa

Answer 8

Rhodopsin mutation causes rod degeneration –> less secretion of proteins req for cones –> cones degeneration –> progressive constriction of visual field

Question 9

Usher’s syndrome

Answer 9

retinitis pigmentosum + hearing loss

Question 10

Achromatopsia

Answer 10

mutated transducin or CNG ion channel –> cones unable to hyperpolarize in response to light
severe photophobia due to rod saturation

Question 11

Primary open angle gluacoma

Answer 11

chronic obstruction of drainage system in eye –> incr IOP due to fluid buildup –> damage option n. –> vision loss

Question 12

Angle Closure Glaucoma

Answer 12

acute narrowing of angle btwn cornea and iris –> block drainage of aq humor –> incr IOP–> vision loss

Question 13

cataracts

Answer 13

opacification of lens with age

Question 14

trigeminal neuralgia (tic douloureux)

Answer 14

recurrent episodes of excruciation pain provoked by certain trigger points in V2/V3 territory

Question 15

Temporomandibular joint disorder

Answer 15

chronic pain of jaw, mastication mm. recurrent HAs, ear pain

Question 16

Cerebral achromatopsia

Answer 16

damage to V4 : sudden impairment in color perception

Question 17

cerebral akinetopsia

Answer 17

bilateral damange to v5/MT : sudden impairmnet in ability to detect motion (“freeze frames”)

Question 18

Marcus Gunn Pupil

Answer 18

afferent/sensory pupillary defect : no resp in either eye in response to pupil light reflex

Question 19

Argyll Robertson Pupil

Answer 19

Accommodation Reflex Rresent but Pupillary Reflex Absent

Question 20

Benign Paroxysmal Positional Vertigo (BPPV)

Answer 20

posterior canal canalithiasis = activated by otoconia (crystal detached from utricle/saccule and collected in the semicircular canals)

diag: nystagmus towards the affected side during dix-hallpike test

Question 21

Superior Canal Dehiscence

Answer 21

loss of bone covering the superior canal causing easy excitation by stimuli and dizziness from sounds

Question 22

Labyrinthitis

Answer 22

loss of vestibular function in all canals due to inflammation in inner ear
sx: unilateral weakness and hearing loss

Question 23

vestibular neuronitis

Answer 23

loss of vestibular function in canals but without hearing loss
sx: nystagmus to unaffected side, motion sensitivity, vertigo

Question 24

meniere’s disease

Answer 24

inner ear fluid imbalance causing episodic vertigo and fluctuating hearing , tinnitus, aural fullness