Neuromuscular

Question 1

Diagnostic Criteria of Progressive Muscular Atrophy

Answer 1

clinical diagnosis requiring LMN dysfunction in 2+ myotomes

Question 2

How is Progressive Muscular Atrophy clinically differentiated from ALS?

Answer 2

lack of UMN signs, such as hyperreflexia and spasticity

Question 3

diagnosis indicating isolated progressive LMN dysfunction

Answer 3

Progressive Muscular Atrophy (PMA)

Question 4

diagnosis indicating isolated progressive UMN dysfunction

Answer 4

Primary Lateral Sclerosis (PLS)

Question 5

diagnosis indicating progressive UMN and LMN dysfunction

Answer 5

Amyotrophic Lateral Sclerosis (ALS)

Question 6

What is the most common cause of death in ALS?

Answer 6

respiratory failure

Question 7

Are there sensory changes in Primary Lateral Sclerosis?

Answer 7

No. This disease has only motor manifestations.

Question 8

Neuromuscular disorder characterized by fluctuating, fatiguable skeletal muscle weakness

Answer 8

Myasthenia Gravis

Question 9

What is the pattern of weakness in a patient with MG?

Answer 9

Proximal limb muscles are preferentially involved. Bulbar and ocular muscles may also be involved.

Question 10

What characteristically causes worsening of weakness in MG patients?

Answer 10

physiologic or psychological stress

Question 11

What is the pattern of inheritance of Spinobulbar Muscular Atrophy?

Answer 11

X-linked

Question 12

X-linked motor neuron disease caused by a CAG trinucleotide repeat in the androgen receptor gene

Answer 12

Spinobulbar Muscular Atrophy

Question 13

What is Inclusion Body Myositis?

Answer 13

An inflammatory myopathy primarily affecting older adults characterized by progressive asymmetric weakness and atrophy involving both proximal and distal limb muscles

Question 13

What are the clinical characteristics of Spinobulbar Muscular Atrophy?

Answer 13

• LMN dysfunction
• bulbar muscle weakness
• gynecomastia
• erectile dysfunction
• infertility

Question 14

What are the histopathologic characteristics of Inclusion Body Myositis?

Answer 14

Mononuclear cell infiltrates in non-necrotic fibers, sarcoplasmic rimmed vacuoles, myofiber degeneration/regeneration/necrosis, and variability of fiber size.
Congo Red staining may identify amyloid deposits in vacuolated fibers.

Question 15

How high is the serum Cr in Inclusion Body Myositis?

Answer 15

Mildly elevated, <10x the upper limit of normal

Question 16

How might Inclusion Body Myositis appear on electron microscopy?

Answer 16

Inclusions consisting of 15-18 nm tubulofilaments in the sarcoplasm and myonuclei or amyloid deposits

Question 17

What are the histopathologic characteristics of Dermatomyositis?

Answer 17

perivascular and perimysial inflammation grouped in an area of the fascicle, with perifascicular necrosis

Question 18

What peripheral nerve is affected in Pronator Teres Syndrome?

Answer 18

median nerve

Question 19

Sensory loss over the lateral aspect of the palm due to repetitive supination/pronation of the forearm

Answer 19

Pronator Teres Syndrome

Question 20

Radiculopathy at which nerve root would cause weakness in elbow extension and wrist flexion?

Answer 20

C7

Question 21

Radiculopathy at which nerve root would cause weakness in thumb extension and ulnar deviation of the wrist?

Answer 21

C8

Question 22

What are the clinical characteristics of radial neuropathy at the spiral groove?

Answer 22

Weakness of the brachioradialis, wrist extension, and finger extension; sensory loss over the dorsum of the hand. The triceps is spared.

Question 23

What proportion of patients with MG are seropositive for ACh-R Antibodies?

Answer 23

80-90%

Question 24

Muscular dystrophy due to a mutation in collagen type VI

Answer 24

Ullrich's congenital muscular dystrophy

Question 25

What are the clinical characteristics of Ullrich's congenital muscular dystrophy?

Answer 25

neonatal weakness, distal hypermobility, multiple contractures, protrusion of the calcanei

Question 26

Duchenne muscular dystrophy inheritance pattern

Answer 26

X-linked recessive

Question 27

What genetic mutation causes Duchenne muscular dystrophy?

Answer 27

frameshift mutation at the Xp21 locus resulting in an absence of dystrophin

Question 28

What is dystrophin?

Answer 28

a rod-shaped protein that anchors the contractile proteins to the outside of the muscle cell

Question 29

How is Duchenne muscular dystrophy ultimately diagnosed?

Answer 29

via genetic testing or muscle biopsy

Question 30

What are the histopathologic characteristics of Duchenne muscular dystrophy?

Answer 30

muscle necrosis, phagocytosis, fiber size variation, fibrosis, basophilia, hyaline fibers and absence of dystrophin staining

Question 31

Describe the Gower's maneuver seen in Duchenne muscular dystrophy.

Answer 31

Patient has difficulty rising from the floor and uses their hands to push against their knees to assist in this motion

Question 32

Myokymia

Answer 32

Involuntary spontaneous quivering of a few muscle fibers or bundles within a muscle insufficient to move a joint often associated with denervation

Question 33

What are the first-line oral medications for neuropathic pain?

Answer 33

gabapentin, pregabalin, duloxetine

Question 34

What is the starting dose of gabapentin when used for neuropathic pain?

Answer 34

300 mg TID (start once daily, add a dose every few days until TID)

Question 35

What is the starting dose of pregabalin when used for neuropathic pain?

Answer 35

50 or 75 mg BID (start once daily for a week, then increase to BID)

Question 36

What is the starting dose of duloxetine when used for neuropathic pain?

Answer 36

60 mg daily (start 30 mg for a week, then increase to 60 mg)