[Metabolic neuropathies. I. Diabetic neuropathies].

This is a review article on diabetic neuropathy. The different patterns of diabetic neuropathies, including focal and multifocal, distal symmetrical and autonomic neuropathy are exposed. Length dependent degeneration of fibers is suggested by the pattern of sensory loss and by morphological findings. The various hypotheses on the mechanisms of the neuropathy, including the possible role played by ischemia and by the accumulation of sorbitol in Schwann's cells, are reviewed. The therapeutic implications of the clinical, pathological and biochemical abnormalities are discussed.