Uncommon early-onset neuropathy in diabetic patients

An acute neuropathy rarely occurs early in the course of diabetes mellitus. Five cases are described of adult patients who developed a peripheral neuropathy at the time or shortly after the onset or discovery of diabetes mellitus. Patient 1, an 80-year-old woman who developed a subacute tetraparesis with proximal and distal muscle weakness with normal cranial nerves, proved to have insulin-requiring diabetes mellitus. In the other patients, all men aged 23-34 years, symptomatic neuropathy occurred simultaneously (patient 2) or 1-6 months after the onset of insulin-dependent diabetes mellitus (IDDM) (patients 3-5). Patients 2 and 3 developed a symptomatic multifocal neuropathy; patients 4 and 5, a painful distal symmetrical sensory polyneuropathy (DSSP) shortly after beginning treatment with insulin. Nerve biopsy showed active axonal lesions in patients 2 and 5 and mixed axonal and demyelinating lesions in the others, with severe axon loss in patients 4 and 5. Vasculitic lesions were found in patient 2, who improved without additional treatment. Neurological examination remained unchanged after 2 years in patients 3-5. Although a coincidence cannot be excluded for patients 1-3, whose neuropathy was not of the pattern commonly found in diabetes, it is suggested that acute disequilibrium in the diabetic status may facilitate the occurrence of a variety of neuropathies. Alternatively, the autoimmune process which led to IDDM may also trigger an autoimmune neuropathy with vasculitis (patient 2) or demyelinative nerve lesions. Only the distal symmetrical sensory polyneuropathy with severe axonal lesions observed in patients 4 and 5 seems directly related to diabetes mellitus. In spite of their occurrence shortly after beginning insulin therapy, the role of treatment with insulin in the onset is uncertain.