Biochemical studies of patients with Cuban epidemic neuropathy

In 1992-1994, a disorder known as the epidemic neuropathy afflicted more th an 50,000 Cubans. Three different forms of the illness were identified: epi demic optic neuropathy, peripheral neuropathy and mixed optic and periphera l neuropathy. The causes are still unknown. Skeletal muscle biopsy samples were analyzed by standard histological techniques and by biochemical assays . Elevated activities of citrate synthase, a non-respiratory-chain mitochon drial matrix enzyme, suggested possible mitochondrial proliferation in 7 of the 8 patients. Nicotinamide adenine dinucleotide phosphate (NADP) levels were higher in the patients than in the controls (p = 0.04). Levels of nico tinamide adenine dinucleotide (NAD) and the reduced compounds NADH and NADP H were comparable in patients and controls. Elevations of succinate dehydro genase and citrate synthase activities and high NADP(+) levels suggest that alterations of mitochondrial functions may be associated with this disorde r. Copyright (C) 2001 S. Karger AG, Basel.