Proximal Myopathy

Question 1

What is it?

Answer 1

Muscle disease unrelated to any disorder of innervation or neuromuscular junction

Question 2

What are the main causes? (6)

Answer 2

1. Congenital Muscular Dystrophies e.g Duchennes
2. Idiopathic Myopathies with immune-mediated phenomena e.g Sarcoidosis, Dermatomyositis
3. Acute Alcoholic Myopathy
4. Infection e.g Influenza
5. Endocrine e.g Cushing’s
   6, Drug induced e.g steroids

Question 3

Are they common?

Answer 3

No they’re all relatively uncommon, duchenne is the most common 1 in 3000

Question 4

Symptoms (7)

Answer 4

Muscle weakness, impaired muscle function, muscle pain, malaise, fatigue, dark urine (suggests myoglobinuria), no sensory symptoms

Question 5

Signs(4)

Answer 5

Symmetrical proximal muscle atrophy, hyporeflexia, normal conscious level, Gottron Papules (dermatomyositis)

Question 6

Differentials (4)

Answer 6

Guillain Barre, Charcot Marie tooth, Myaesthenia Gravis, Cerebral Palsy

Question 7

What bloods would you do? (8)

Answer 7

FBC, ESR, CRP, TFT, Antinuclear Antibodies, U&E, Creatinine, Serum Myoglobin

Question 8

Other investigations (7)

Answer 8

Urinalysis, Urine Microscopy, ECG, Electromyography, MRI, Muscle biopsy, Genetic testing

Question 9

Treatment (10)

Answer 9

*it depends on the individual cause, management of the airway and breathing, physiotherapy, may require tracheotomy and permanent ventilation, tendon release surgery, walking aids, splints, wheelchairs, family support, dietary advice

Question 10

Complications (7)

Answer 10

Respiratory failure, Aspiration Pneumonia, Joint contractures, Chest deformities, Spinal Deformities, Scolosis, Malignant Hyperthermia

Question 11

Is there a good prognosis?

Answer 11

Depends on the specific diagnosis but the primary disorders are generally incurable, can treat secondary by treating the underlying cause