• We describe a 6-year-old boy who presented with progressive muscle weakness. Additional investigations revealed the existence of a myopathy and a pure motor neuropathy. Biochemical studies in muscle tissue showed a defect of NADH dehydrogenase (complex I). The patient dramatically improved on treatment with riboflavin and l-carnitine. Seven months after the start of the treatment, complex I activity was determined again and appeared to be normalized. Normalization of the enzymatic defect at this level has not been reported before. We provide a survey of nine patients with pure myopathy, associated with complex I deficiency and onset of symptoms in childhood.
Bernsen PLJA, Gabreëls FJM, Ruitenbeek W, Sengers RCA, Stadhouders AM, Renier WO. Successful Treatment of Pure Myopathy, Associated With Complex I Deficiency, With Riboflavin and Carnitine. Arch Neurol. 1991;48(3):334–338. doi:10.1001/archneur.1991.00530150106028