Primary Muscle Disorders

Question 1

Differential diagnosis with polyneuropathies

Answer 1

Tendon reflexes are present
No sensory signs
No spincterian problems
No autonomic signs

Question 2

Etiologies of primary muscle disorders

Answer 2

Inflammatory myopathies:
Hereditary myopathies
Myotonic dystrophy 
Proximal myotonic myopathy 
Distal myopathy
Metabolic and toxic myopathies

Question 3

Neuromuscular junction disorders

Answer 3

Myasthenia gravis
Myasthenic - myopathic syndrome
Congenital myasthenic syndrome
Myasthenic weakness due to AB

Question 4

What is myasthenia gravis?

Answer 4

Autoimmune attack against acetylcholine receptors on postsynaptic membrane of NMJs

Primary site of AB production is the thymic gland

Question 5

What are the symptoms of myasthenia gravis?

Answer 5

Fluctuating weakness of muscles, recovered when resting

Insidious onset

Craniofacial nerves are to 50% included: dropped eyelid, intermittent Diplopia

Weakness in trunk and limbs

Respiratory muscle involvement

No muscle atrophy

Question 6

Treatment for myasthenia gravis

Answer 6

ACh esterase drugs: neostigmine, pyridostigmine

Thymectomy

Corticosteroids

Immunosuppressants

IV immunoglobulin

Question 7

Clinical picture of PMD

Answer 7

Proximal muscle involvement
Decreased muscle Tonus
Muscle atrophy
Loss of bulk

Pain, spasm, cramps, muscular hypertrophy, fatigue, stiffness