Lipid storage myopathies with unusual clinical manifestations

We describe the clinical presentation, course and pathologic findings found in three adult patients with lipid storage myopathy. Excessive lipid storage was found in Type 1 fibers of muscle. Clinical improvement on oral levo-carnitine therapy suggests the possibility of carnitine deficiency as the most likely etiology in two of the patients and one had mitochondrial myopathy confirmed on genetic analysis.