Ch 27 - Peripheral Nerves

Question 1

Neurofibromatosis type 1 or 2 - chromosome 22q (Merlin’s) loss of tumor suppressor

Answer 1

Type 2

Question 2

Peripheral neuropathy that presents with onion bulls (excessive proliferation of Schwann cells wrapping around an axon leading it to look like layers of an onion)

Answer 2

Chronic inflammatory demyelinating poly(radiculo)neuropathy

Question 3

Group of syndromes characterized by:
Myoclonic epilepsy with ragged red fibers
Leber hereditary optic neuropathy (LHON)

Answer 3

Mitochondrial myopathies

Question 4

Scaling erythematous eruption or dusky red patches over the knuckles, elbows, and knees
What systemic autoimmune disease is this seen in?

Answer 4

Gottron papules

Dermatomyositis

Question 5

Most common muscular dystrophy with early onset

Answer 5

Duchenne muscular dystrophy

Question 6

What is POEMS syndrome, and what neuropathy associated with malignancy is it associated with?

Answer 6

Polyneuropathy, Organomegaly, Endocrinopathy, Monoclonal gammopathy, Skin changes
Monoclonal Gammopathy

Question 7

Most common acquired inflammatory peripheral neuropathy

Answer 7

Chronic inflammatory demyelinating poly(radiculo)neuropathy

Question 8

What rate the X-linked muscular dystrophies?

Answer 8

Duchenne and Becker muscular dystrophy

Question 9

Most common Inflammatory myopathy in children

Answer 9

Dermatomyositis - juvenile type

Question 10

Ion channel myopathy (channelopathy) mutation that is the most common cause of hypokalemia paralysis
Which ion channel is it a mutation of?

Answer 10

CACNA1S mutation

Calcium channel

Question 11

Toxic myopathies are slowly progress muscle weaknesses due to drugs
What is the key class of drug?

Answer 11

Statins, regardless of dose or subtype

Question 12

Virus that causes painful, vascular skin eruption (shingles)in a sensory dermatomal pattern

Answer 12

Varicella Zoster

Question 13

Schwannomas are benign tumors with Schwann cell differentiation that arise directly form peripheral nerves
What protein are they positive for?

Answer 13

S-100 (+)

Question 14

Neurofibromatosis type 1 or 2 - cafe-au-lait spots (macular cutaneous hyperpigmentation)

Answer 14

Type 1

Question 15

Most common inherited peripheral neuropathy (> 50 different mutations)

Answer 15

Charcot-Marie-Tooth (CMT) disease

Question 16

The “bag of worms” appearance describes a ropy thickening of multiple fascicles seen in what tumor?

Answer 16

Plexiform neurofibroma

diffuse neurofibromas has a plaque-like appearance

Question 17

Most common inflammatory myopathy in patients > 65

Answer 17

Inclusion body myositis

Question 18

Which muscular dystrophy has an absence of normal sarcolemmal immunohistochemical staining pattern

Answer 18

Duchenne muscular dystrophy

Question 19

Nuclear free zones between pallisading nuclei

What tumor are these seen in?

Answer 19

Verocay bodies

Schwannoma

Question 20

RYR1 mutation (ryanodine receptor) ion channel myopathy is associated with malignant hyperthermia (hypermetabolic state (tachycardia, tetany, late hyperpyrexia) triggered by anesthetics)
What is the treatment?

Answer 20

Dantrolene

Question 21

Triad of slowly progressive humeroperoneal weakness, cardiomyopathy (conduction defects), and early contracture of Achilles’ tendon, spine, and elbows seen in ______

Answer 21

Emery-Dreifuss muscular dystrophy (EMD)

Question 22

Which muscular dystrophy has reduced immunohistochemical staining

Answer 22

Becker

Question 23

Most common cause of non-traumatic limb amputations in the US

Answer 23

Diabetes mellitus

Question 24

Increased serum CK (in first decade of life, falls as disease progresses and muscle mass is lost) helps in diagnosing what disease?

Answer 24

X-linked muscular dytrophy

Question 25

Most common cause of peripheral neuropathy

Answer 25

Diabetes mellitus

Question 26

Neurofibromatosis type 1 or 2 - bilateral CNVIII schwannomas

Answer 26

Type 2