P KZN HYPOTHD X MUSCLE X CWH B0034261

 There are 4 subtypes of myopathy associated with hypothyroidism: myasthenic syndrome, atrophic form, Kocher-Debre-Semelaigne syndrome, Hoffman syndrome.

1. Myasthenic syndrome is associated with ptosis and severe weakness beginning in childhood that can progress to loss of mobility in later life.
2. Severe muscle atrophy is seen in the atrophic form of hypothyroid myopathy.
3. Kocher-Debre-Semelaigne syndrome is seen in childhood and is associated with generalized muscular hypertrophy, myxoedema, short stature, and cretinism.
4. Hoffmann syndrome is usually seen in adults and characterized by pseudohypertrophy, painful spasms, proximal muscle weakness, and stiffness. This is generally seen in primary hypothyroidism and very rarely with secondary hypothyroidism. The cause of muscle pseudohypertrophy in Hoffmann’s syndrome is complex and largely unclear. It is postulated to be due to deposition of glycosaminoglycans and increased muscle fiber size. The muscles commonly involved are the tongue, arm and leg muscles. [5]

Rhabdomyolysis is, fortunately, a rare complication of severe and untreated hypothyroid myopathy, but can be life-threatening. Common precipitating factors are vigorous exercise, trauma, electrolyte abnormalities, and alcohol consumption.