Update on diabetic neuropathy

This review will focus on recent advances in the field of diabetic neuropathy, with an emphasis on distal symmetric sensory and sensorimotor polyneuropathy. Some new information in the areas of diabetic amyotrophy and diabetic autonomic neuropathy will also be reviewed.

The pathogenesis of diabetic neuropathy is multifactorial. There is increasing evidence to link abnormalities in the polyol pathway to the pathogenesis of diabetic neuropathy. In addition, there appear to be abnormalities of nerve regeneration and of sodium and calcium channels. Aldose reductase inhibitors have shown promise in animal models for reversing neuropathy if started early and used for a sufficient time, but those used to date in human trials are probably not of sufficient potency. Neurotrophic factors and vascular endothelial growth factor both also show promise. Specific recommendations and pathways for diabetic foot care have been devised. Lamotrigine and bupropion represent new treatments for neuropathic pain. The role of impaired glucose tolerance is being explored as it relates to polyneuropathy.

An increasing understanding of the pathogenetic mechanisms holds out promise for the effective treatment of diabetic neuropathy. The early detection of abnormal glucose metabolism is particularly important, as treatments will probably be most effective if administered early in the course of the neuropathy, when abnormalities of peripheral nerves are more likely to be reversible.