Diabetic neuropathies: clinical manifestations and current treatment options

Diabetic neuropathies are a heterogeneous group of disorders that include a wide range of abnormalities. They can be focal or diffuse, proximal or distal, affecting both peripheral and autonomic nervous systems, causing morbidity with significant impact on the quality of life of the person with diabetes, and can result in early death. Distal symmetric polyneuropathy, the most common form of diabetic neuropathy, usually involves small and large nerve fibers. Small-nerve-fiber neuropathy often presents with pain but without objective signs or electrophysiologic evidence of nerve damage, and is recognized as a component of the impaired glucose tolerance and metabolic syndromes. The greatest risk resulting from small-fiber neuropathy is foot ulceration and subsequent gangrene and amputation. Large-nerve-fiber neuropathies produce numbness, ataxia and uncoordination, impairing activities of daily living and causing falls and fractures. A careful history and detailed physical examination are essential for the diagnosis. Symptomatic therapy has become available and newer and better treatment modalities, based on etiologic factors, are being explored with potential for significant impact on morbidity and mortality. Preventive strategies and patient education still remain key factors in reducing complication rates and mortality.