Effect of early nerve release on the progression of neuropathy in diabetic rats.

Diabetic neuropathy renders the peripheral nerves to be more susceptible to compression at potential entrapment sites. We evaluated the effects of "prophylactic" decompression procedures on the progression of diabetic neuropathy in an experimental model. Thirty diabetic Zucker rats were studied. Group I, II, and III rats were followed up for 12 weeks and IV, V, and VI rats for 24 weeks. Group III and VI rats served as short- and long-term controls without any surgical intervention. Group I and IV rats had tarsal tunnel release (TTR); group II and V rats had TTR and peroneal nerve release (PNR) procedures on their left legs. Nerve function was assessed by pinprick, toe spread tests, sciatic function index (SFI), somatosensory evoked potential (SSEP) analysis, and gastrocnemius muscle wet weight measurements.SFI analysis revealed a statistically significant difference between the combined TTR-PNR and nonoperative control groups at both short- and long-term follow-up (P </= 0.01). SSEP result analysis of operated left and nonoperated right sides revealed a statistically significant difference in P1 latency values at both short- and long-term follow-up (P < 0.05). We confirmed beneficial effects of decompression procedures at early onset of diabetes before the metabolic nerve injury advanced into an axonal loss.