Arrest of neuropathy and myopathy in abetalipoproteinemia with high-dose vitamin E therapy.

A 16-year-old girl, one of dizygotic twins, presented in 1976 complaining of a 1-year history of a lack of coordination and an inability to run. The results of biochemical tests confirmed the diagnosis of classic abetalipoproteinemia. In addition to the recognized neurologic features of this disorder, she had a reduced evoked motor unit potential and markedly elevated serum levels of muscle enzymes, which suggested myositis. The serum vitamin E level was markedly decreased. Oral therapy with vitamin E, 800 mg daily, was begun, and in 1981 the dosage was increased to 3200 mg daily. Over the 7 years of follow-up she improved clinically, there was an increase in the evoked motor unit potential, the serum levels of some of the muscle enzymes decreased to normal, and the serum and tissue vitamin E levels increased significantly. It was concluded that treatment with high doses of vitamin E was responsible for the arrest of the usually progressive neuropathy and myopathy.