Myopathies

Myopathies

Objectives
To recognize existence of muscle diseases

To differentiate them from other disorders.

To know about various causes of myopathy.

To know of basic investigations of myopathy.

CLINCIAL PICTURE
Proximal, large muscles.
Steadily progressive , s.t. episodic
Symmetric
Preserved tone and tendon reflexes
No sensory\autonomic abnormality
Cardiac failure
Cardiac conduction abnormalities
Respiratory problems (sleep apnea)


Differential Diagnosis
Lower motor neuron disorders
Neuropathy (reflexes, distal, Sensory, autonomic)
Neuromuscular (bizarre, asymmetric, variable)
Anterior horn cell (reflexes)

Outline of investigations

Creatinine phosphokinase (CK)
EMG-NCS
Muscke Biopsy (histo-biochemistry)
ECG
CXR
Underlying cause:
Genetic\metabolic screen and counseling
Inflammatory/Endocrine/Electrolytes etc..

Causes

Hereditary
Dystrophies
Congenital
Inherited metabolic
Channelopathies

Duchenne Muscular dystrophy

Muscular Dystrophies

Fascio-Scapulo-Humoral Dystrophy

Periodic Paralysis:

Hypokalemic :
Na, Ca channel
After heavy carbohydrate meals, salt
Treament:
Low sugar\salt diet, rich K diet
Acetazolamide

Hyperkalemic :

Na channel
After K rich meals
Treatment: low K diet

Acquired causes: