A 61-year-old woman had proximal muscle weakness since 38 years of age. Eventually, her distal muscles became affected and she showed widespread muscle wasting, absent tendon reflexes, and electromyographic findings of a neuropathy. On biopsy, there was a lipid storage myopathy, lipid-containing vacuoles in leukocytes, and vacuoles in Schwann cells. The muscle carnitine level was abnormally low, but the serum carnitine level was normal. The findings are consistent with a generalized disorder of carnitine metabolism that may involve carnitine transport across cell membranes.
Markesbery WR, McQuillen MP, Procopis PG, Harrison AR, Engel AG. Muscle Carnitine Deficiency: Association With Lipid Myopathy, Vacuolar Neuropathy, and Vacuolated Leukocytes. Arch Neurol. 1974;31(5):320–324. doi:10.1001/archneur.1974.00490410068007
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