Neuromuscular Disease

Question 1

ALS

Answer 1

Progressive upper and lower neuron disease
5% genetic, the rest sporadic
Clinical fx: limb weakness, cramps, Fasiculations, spasticity, hyperreflexia
Bulbar: dysarthria, dysphagia
Respiratory weakness
Associated with frontotemporal dementia

Question 2

Spinobulbar muscle atrophy

Answer 2

Kennedy disease
X linked androgen receptor mutation
Lower motor neuron degeneration
Androgen insensitivity

Question 3

Myasthenia gravis

Answer 3

Antibodies to post synaptic membrane Ach receptor

Presents with fatiguable weakness, extra ocular weakness, bulbar symptoms, proximal limb weakness

Question 4

Lambert Eaton Myasthenic Disease

Answer 4

Antibodies to Presynaptic membrane calcium channels
Clinical: proximal weakness with upward spread, decreased reflexes with facilitation, autonomic dysfunction

be sure to screen for malignancy

Question 5

Botulism

Answer 5

Neurotoxin from clostridium botulinum

Inhibits Presynaptic Ach release
Clinical: descending fatiguable weakness, fixed dilated pupils, ptosis

Question 6

Dermatomyositis

Answer 6

Antibodies to muscle (jo-1, SRP)
Proximal bilateral muscle weakness
Heliotrope rash, gottrons Papules, erythematous rash

Question 7

Inclusion body myosotis

Answer 7

Proximal quad weakness and distal finger flexing weak
Bulbar weakness
Older men

Question 8

Myotonic dystrophy

Answer 8

AD DMPK mutation
Myotonia p- cannot relax muscles
Associated with specific phenotype that includes frontal balding, narrow face, endocrine dysfunction

Question 9

Duchenne muscular dystrophy

Answer 9

X linked mutation in dystrophin, frame shift causing non functional protein
Young onset, progressive proximal muscle weakness (gowers sign)
Toe walking, calf pseuohypertrophy, scoliosis, cardiomyopathy