Neuropathy and Myopathy

Question 1

Mononeuropathy

Answer 1

A single large, “named” nerve is affected, usually by compression or trauma

Question 2

Polyneuropathy

Answer 2

AKA peripheral neuropathy and is a disorder of multiple large or small nerves

Question 3

What is the most common presentation of polyneuropathy?

Answer 3

Stocking and glove sensory deficits

Question 4

Paresthesia

Answer 4

Spontaneous tingling with a pins and needles sensation

Question 5

Dysesthesia

Answer 5

Unpleasant sensation from a non-noxious stimulus

Question 6

Carpal Tunnel Syndrome

Answer 6

Results from the compression of the median nerve in the wrist

Question 7

What is the most common mononeuropathy?

Answer 7

Carpal Tunnel Syndrome

Question 8

Guillain-Barre Syndrome

Answer 8

Affects people of all ages and occurs most often after an infection - immune system will target myelin and cause an ascending areflexic paralysis

Question 9

What infection is Guillain-Barre Syndrome associated with?

Answer 9

Campylobacter jejuni

Question 10

What is a lab finding with Guillain-Barre Syndrome?

Answer 10

Elevated protein found in the CSF

Question 11

What is one of the most frequent causes of polyneuropathy?

Answer 11

Diabetes mellitus

Question 12

Myopathy

Answer 12

Pathology of the muscle directly which can be seen with proximal weakness or fatigue alongside normal sensation and late loss of reflexes after significant atrophy

Question 13

What are some possible causes of myopathy?

Answer 13

• Viral infection
• Statins
• Cushing’s

Question 14

Polymyositis

Answer 14

Inflammation and weakness of multiple muscles may occur from viral infections or drug reactions

Question 15

What is the most common cause of polymyositis in the US?

Answer 15

An autoimmune cause is most common in the USA:
– proximal weakness developing over weeks to months
– a rash around the eyes or fingers may occur

Question 16

Dermatomyositis

Answer 16

Rash around the knuckles and periorbital areas from polymyositis

Question 17

Muscular dystrophy

Answer 17

Hereditary myopathies of variable progression and severity

Question 18

What is the inheritance of Duchenne’s Muscular Dystrophy?

Answer 18

X-linked

Question 19

What is the mutation of Duchenne’s muscular dystrophy?

Answer 19

Absence of dystrophin, a critical structural protein in muscle and involves respiratory and cardiac muscles as well

Question 20

What are some clinical signs of Duchenne’s muscular dystrophy?

Answer 20

• Calf pseudohypertrophy

- Proximal weakness since childhood

Question 21

What is Gower’s maneuver?

Answer 21

It is seen in Duchenne’s dystrophy where young children push up their trunk to get to a standing position

Question 22

Myotonic Dystrophy Type I

Answer 22

Autosomal dominant. Excessive trinucleotide repeats on Ch19 which produces abnormal protein kinase in muscle fibers.

Question 23

Myotonia

Answer 23

Impaired relaxation of muscles after volitional contraction

Question 24

Motor Neuron Disease

Answer 24

Disorders, occasionally hereditary, where degeneration of upper (UMN) or lower (LMN) motor neurons, or both, occurs with varying severity and rate of progression

Question 25

Spinal Muscular Atrophy

Answer 25

Group of disorders that involve just the anterior horn cells - most are hereditary with LMN signs of weakness, atrophy, areflexia, fasciculations

Question 26

Werdnig-Hoffmann Disease

Answer 26

Infantile onset of anterior horn cell degeneration that is a terminal condition due to
rapid development of diffuse weakness, with no current curative treatment

Question 27

What is the most common motor neuron disease?

Answer 27

Amyotrophic Lateral Sclerosis

Question 28

Amyotrophic Lateral Sclerosis

Answer 28

Progressive degeneration of UMN and LMN

Question 29

What are the symptoms of ALS?

Answer 29

Frequently begins with regional weakness and atrophy of a limb (e.g., shoulder), which spreads and becomes bilateral; or initial weakness of swallowing or speech

Question 30

What mutation is seen in familial ALS?

Answer 30

Defective Copper-Zinc Superoxide Dismutase

Question 31

What is the only drug for ALS (not curative)?

Answer 31

Riluzole (glutamate antagonist) prolongs survival by months (glutamate may “overly excite” motor neurons)