Neuropathy, Myopathy, & Motor Neuron Dz

Question 1

single major named nerve has deficits due to trauma/compression

Answer 1

mononeuropathy

Question 2

localization of mononeuropathy via

Answer 2

EMG

Question 3

disorder of multiple nerves, sxs often symmetrical, sensation affected early, dec reflexes early on

Answer 3

polyneuropathy or peripheral neuropathy

Question 4

why are distal regions affected first for peripheral neuropathy

Answer 4

longest nerves affected first b/c metabolic maintenance and axoplasmic flow are more susceptible to neurotoxic factors

Question 5

spontaneous tingling

“pins and needles”

Answer 5

paresthesia

Question 6

unpleasant sensation from non-noxious stimuli

Answer 6

dysesthesia

Question 7

sxs of polyneuropathy or peripheral neuropathy

Answer 7

sxs often symmetrical, sensation affected early, dec reflexes early on, weakness/sensation affected distally first

Question 8

2 pathological processes in neuropathy

Answer 8

demyelination

axonal degeneration

Question 9

mononeuropathy from focal compression due to

Answer 9

demyelination
ex: carpal tunnel
(axonal degen is secondary process)

Question 10

2 ex of demyelination

Answer 10

guillan barre (polyneuropathy)
carpal tunnel (mononeuropathy)

Question 11

mechanism of axonal loss

Answer 11

Wallerian degen - axons and myelin degenerate distal to where nerve was injured

Question 12

support scaffolding that guides regrowing of axons

Answer 12

perineurium

Question 13

lack of perineurium leads to

Answer 13

resprouting axons piling up in a bulbous neuroma (often painful)

Question 14

primary pathology for polyneuropathies due to toximetabolic cause

Answer 14

axonal degen (demyelination is secondary process)

Question 15

nerve at wrist, elbow, and fibular head

Answer 15

wrist - median n
elbow - ulnar n
fibular head - common peroneal n

Question 16

tests electrical activity and function of nerves and muscles

Answer 16

EMG

Question 17

if EMG suggests chronic polyneuropathy due to inflamm, immune, or vasculitis - confirm dx via

Answer 17

sural (sensory n) biopsy

Question 18

biopsy of sural nerve results in

Answer 18

permanent numbness along lateral foot

Question 19

treatable causes of polyneuropathy - screen for

Answer 19

DM
liver/kidney probs
Vit B12 deficiency
hypothyroidism
anemia/leukemia (CBC)

Question 20

MOA of topical capsaicin

Answer 20

substance P depleter

Question 21

oral meds for neuropathic pain

Answer 21

anticonvulsants (gabapentin, pregabalin, carbamazepine) or antidepressants (amitriptyline or duloxetine)

Question 22

immune system targets peripheral nerve myelin and gives ascending, areflexic paralysis

Answer 22

guillan barre (after viral illness, surgery, or trauma)

Question 23

guillan barre weakness plateaus when

Answer 23

after 3-4 wks

Question 24

guillan barre EMG

Answer 24

shows asymmetrical demyelination in proximal and distal segments of diff nerves

Question 25

guillan barre CSF

Answer 25

may have elevated protein, few wbcs (if any), no signs of infection

Question 26

faster recovery for guillan barre if you administer

Answer 26

plasmapheresis (removes circulating ab) or IVIG (gives ab that counteract the autoimmune process)

Question 27

myopathy sxs

Answer 27

proximal weakness, nl sensation, late loss of reflexes (after atrophy)

Question 28

rapid weakness from viral induced breakdown of musc fibers seen with

Answer 28

influenza

Question 29

meds that can give weakness

Answer 29

statins | corticosteroids

Question 30

endocrine dz that can give myopathy

Answer 30

cushing's | hypothyroid

Question 31

dx of myopathy

Answer 31

measure creatine kinase (CK) EMG muscle biopsy

Question 32

inflammation of multiple muscles, typically autoimmune in US

Answer 32

polymyositis

Question 33

myositis w/ periorbital and knuckle rash

Answer 33

dermatomyositis

Question 34

muscle biopsy of myositis

Answer 34

inflamm cell infiltrates admist necrotic and regenerating musc fibers

Question 35

hereditary myopathies of variable progression/severity

Answer 35

musc dystrophies

Question 36

death for duchenne's caused by

Answer 36

weak respiratory musc or cardiomyopathy

Question 37

excessive trinuc repeats on chromosome 19 giving abnl protein kinase

Answer 37

myotonic dystrophy type 1, autosomal dominant

Question 38

sxs of myotonic dystrophy

Answer 38

weakness of distal limbs, neck, and face, weak jaw closure (often hangs open)

Question 39

impaired relaxation of muscle after volitional contraction

Answer 39

myotonia

Question 40

exam step to elicit myotonia

Answer 40

percussion of thenar musc w/ reflex hammer

Question 41

other sxs of myotonic dystrophy not neuro related

Answer 41

cataracts, frontal baldness, infertility, cardiac arrhythmias

Question 42

tracts for UMN

Answer 42

CST - anterior horn cells | corticobulbar tract - CN (LMNs)

Question 43

dz that only involves anterior horn cells, often hereditary

Answer 43

SMA

Question 44

SMA sxs

Answer 44

LMN signs - weakness, atrophy, fasciculations, hyporeflexia

Question 45

infantile onset SMA

Answer 45

Werdnig Hoffman

Question 46

slowly progressive atrophy of one limb or restricted segments of limbs, normal lifespan

Answer 46

benign focal amyotrophy

Question 47

familial degen of CST in lateral columns of spinal cord not due to structural/metabolic issues

Answer 47

primary lateral sclerosis (weakness + UMN signs)

Question 48

dz where only corticobulbar tract is involved

Answer 48

psuedobulbar palsy (facial weakness, dysphagia, hoarseness, impaired chewing, dysarthria) w/ inc jaw jerk

Question 49

cause of pseudobulbar palsy

Answer 49

MS lesions, trauma, tumors, b/l mutl cerebral infarcts

Question 50

focal weakness/atrophy in limb ("drop") that spreads and becomes b/l, male 40-70 y/o

Answer 50

ALS

Question 51

ALS that starts w/ dysarthria, hoarseness, or impaired swallowing

Answer 51

bulbar ALS

Question 52

sxs of ALS

Answer 52

widespread fasciculations, spasticity, hyper-reflexia, atrophy, weakness

Question 53

spared w/ ALS

Answer 53

extraocular musc | bladder/bowel fxn

Question 54

familial ALS cause

Answer 54

defective superoxide dismutase...free radicals destroy motor neurons

Question 55

tx for ALS

Answer 55

no cure, riluzole helps

Question 56

riluzole MOA

Answer 56

opposes excitotoxic effect of glutamate at NMDA receptors