METABOLIC CAUSES OF RECURRENT RHABDOMYOLYSIS

Objectives - The aim of the study was to evaluate the biochemical caus es of recurrent rhabdomyolysis in Finland. Material and methods - We e xamined 22 patients with recurrent rhabdomyolysis, and 26 patients wit h one episode of rhabdomyolysis or other symptoms compatible with meta bolic myopathy. Muscle histopathology and activities of phosphorylase (PHRL) (total and active), phosphofructokinase (PFK), carnitine palmit oyltransferase (CPT) and myoadenylate deaminase (MAD) were studied. Th e limit of enzyme deficiency was defined as enzyme activity less than 5% of the mean of the control subjects. Results - We found 3 patients with muscle PHRL deficiency, 1 patient with PFK deficiency and 1 patie nt with evidence of phosphorylase kinase deficiency. One patient had B acker's muscle dystrophy, 2 patients had unspecified dystrophies, 1 pa tient had Miyoshi myopathy, and 1 patient had a form of mitochondrial encephalomyopathy (MELAS). Conclusion - Enzyme defects were found in 2 3% of the patients with recurrent rhabdomyolysis. Other muscle disease s, muscular dystrophies or myopathies, were detected in 18% of these p atients, emphasizing the value of clinical and histopathological exami nation of patients with previous rhabdomyolysis.