Skin Blood Flow and Current Perception in Pentoxifylline-Treated Diabetic Neuropathy

Abstract

There are several anecdotal reports of improvement in diabetic sensory neu ropathy following a course of pentoxifylline therapy. Pentoxifylline theoretically could improve skin blood flow, thus reducing ischemia at axonal endings. The authors used laser Doppler techniques to measure skin blood flow and mea sured sine wave current perception thresholds (CPTs) in pentoxifylline-treated diabetic patients with sensory neuropathy. Twenty-four patients completed a six-month course of treatment. These patients had a predominantly "stocking" neuropathy; all the major abnormalities on clinical, laser Doppler, and current perception testing were found on the lower extremity. Seventeen of the 24 pa tients reported symptomatic improvement. A careful, graded neurologic exami nation confirmed that improvement, with a decrease in symptom score on the lower extremity (SSDW) from a baseline of 5.0±0.7 to 3.5±0.7 (p < 0.01) and of physical score (PSDW) from baseline 22.0±2.0 to 16.0±1.9 (p < 0.01) after six months. On the lower extremity, there was an increase in laser Doppler measured flow score (FS) both at 35 ° and at 44°C. FSDW (35°) increased from 10±2 to 14±3 at six months (p < 0.05). FSDW (44°) increased from 58±5 to 77 ±7 at six months (p < 0.01). There was an improvement in sine wave current perception measured by current perception threshold score (TS). TSDW dropped from 150±32 to 84±28 at six months (p < 0.03). In patients with dia betic sensory neuropathy, pentoxifylline appears to improve skin blood flow. Current perception thresholds improve in tandem, corroborating improvement in clinical neurologic findings. A double-blind, placebo-controlled study would be appropriate to establish the efficacy of pentoxifylline as therapy of diabetic sensory neuropathy.