{"id":224,"date":"2014-10-12T15:25:30","date_gmt":"2014-10-12T15:25:30","guid":{"rendered":"https:\/\/docneuro.jz7sunfr-liquidwebsites.com\/mcardle-disease\/"},"modified":"2020-01-26T11:30:43","modified_gmt":"2020-01-26T17:30:43","slug":"mcardle-disease","status":"publish","type":"post","link":"https:\/\/docneuro.com\/mcardle-disease\/","title":{"rendered":"McArdle Disease"},"content":{"rendered":"

McArdle disease is a glycogen storage disease in which the enzyme muscle myophosphorylase is deficient. It is commonly known as glycogen storage disease V. The disorder is characterized by exercise-induced muscle pain, myoglobinuria and elevated serum CK sometimes to the degree of clinical rhabdomyolysis with renal dysfunction. Patients have a “second-wind” phenomenon once non-glycogen dependent energy stores can be engaged. This typically happens about 10 minutes after starting aerobic exercise.<\/p>\n

There is usually no family history since the disorder is autosomal recessive. The disorder is rare, with estimates of prevalence ranging between 1:100,000 and 1:200,000.<\/p>\n

Differential diagnosis for McArdle Disease<\/h2>\n

The differential includes other glycogen storage diseases, a variety of somatic genetic myopathies, idiopathic disorders (like toe-walking), mitochondrial myopathy<\/a> disorders, and other causes of myoglobinuria or rhabdomyolysis. Disorders like CPT deficiency<\/a> have some similarities, although triggers and pathology differ. The decision to assess different causes depends on the presenting symptoms, age of onset, and severity.<\/p>\n

Pathological findings in Glycogen Storage Disease V<\/h2>\n

Classic pathological findings on muscle biopsy are shown in the images below, and include:<\/p>\n