Temporal Vascular Changes in Leg with Ulcer Due to Autonomic Neuropathy.

Vascular dysfunction dominates the clinical picture of peripheral autonomic neuropathy in lower extremity.  We have studied functional changes of leg vasculature in 30 patients with chronic ulceration due to peripheral autonomic neuropathy between clinical stages 1 and 3. They suffered from lower extremity wounds. After sympathetic skin response test, pedal arterial blood flow analysis including peak systolic velocity (PSV) and pulsatility index (PI) was made by duplex ultrasonography (DUS) in involved legs. Vascular anatomy of leg was also examined by magnetic resonance angiography.  The mean PSV value was found 58.32 cm/s in stage 1, 35.31 cm/s in stage 2, and 15.71 cm/s in stage 3. The mean PI value was observed 1.17 in stage 1, 1.43 in stage 2, and 1.87 in stage 3. In chronic stage 3, three patients had inadequate arterial blood supply and recurrent ulcer.  We suggest that reduced sympathetic activity due to small fiber neuropathy causes temporal variations in leg blood flow. There was a nonlinear relationship between vascular functional changes and stages of disease with increased, intermediate, and decreased blood flow, respectively. DUS assessment of pedal arteries contributed to differentiation of clinical stages and permitted vascular evaluation in the course of peripheral autonomic neuropathy.