Diabetic Somatic Neuropathies

Boulton AJM, Malik RA, Arezzo JC, Sosenko JM. Diabetes Care. 2004;27:1458-1486.

Diabetic peripheral neuropathy may affect the somatic or autonomic portions of the peripheral nervous system. This article reviews the classification, pathogenesis, assessment, and management of diabetic peripheral neuropathies affecting the somatic nervous system. Diabetic peripheral neuropathies affecting the autonomic nervous system are reviewed elsewhere.[1] Somatic neuropathies in patients with diabetes may be acute or chronic, distal or proximal, symmetric or asymmetric, monofocal or polyfocal. Hyperglycemia is an important risk factor for the development of diabetic neuropathies, but a great deal of evidence implicates additional pathogenetic mechanisms. The natural history, clinical presentation, assessment, and treatment of chronic distal symmetrical polyneuropathy (DPN), the most common type of diabetic neuropathy, is described at length. Recommended screening devices for DPN include the 5.07 (10 g) Semmes-Weinstein monofilament, Rydel-Seiffer tuning fork, tactile circumferential discrimination, and the Neuropen. Recommended quantitative sensory testing (QST) devices include vibration detection (with a bioesthesiometer) and thermal thresholds. Electrophysiological test batteries (eg, multiple tests) are preferable to measurements of maximal nerve conduction velocity (NCV) in a single test; nevertheless, NCV interpretation is described in depth. Near normoglycemia is currently the only widely available pathogenetic treatment for DPN, but future therapies may use antioxidants and PKC β inhibitors. These agents, currently in clinical trials, have shown promising early results. Painful symptoms of DPN can be managed with tricyclic antidepressants, selective serotonin reuptake inhibitors, anticonvulsants, antiarrhythmics, or opioids, but treatment benefits may be limited by side effects. Topical and physical pain treatments may also be considered. All patients with diabetes should have a careful clinical examination of the lower extremities and feet at least once a year. The modified neuropathy disability score (NDS), utilizing vibration perception (with a 128 Hz tuning fork), temperature perception, pinprick, and Achilles reflex, can predict foot ulceration.

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