RESPECTIVE CONTRIBUTIONS OF MECHANICAL AN D VASCULAR FACTORS TO THE PATHOGENESIS OF NEUROACROPATHY

The purpose of this study was to determine the respective contribution s of microcirculatory dysfunction and mechanical stresses to the patho genesis of neurogenic trophic lesions. All patients with polyneuropath y complicated by cutaneous or osteoarticular trophic lesions (perforat ing forefoot ulcers, neurogenic osteoarthropathy) were eligible for th e study. Patients with vascular, articular or neurological disorders o ther than the polyneuropathy were excluded. Digital photoplethysmograp hy was used to evaluate microcirculatory reactivity. Electronic podome try was performed for static and dynamic foot pressure studies. A tech netium-99m bone scan was done to look for evidence of neurogenic osteo arthropathy. The study included 35 patients (16 with alcohol abuse, 7 with diabetes mellitus, 10 with both disorders, one with Charcot-Marie -Tooth disease, and one with neuropathy of unknown etiology). Cutaneou s or osteoarticular trophic lesions were correlated with the presence of static podoscopic abnormalities (dynamic abnormalities apparently h ad no influence per se). Digital vasoplegia was found in 8 of 35 patie nts (23%) and was closely correlated (p<0.0001) with severity of the o steoarthropathy. These data suggest that mechanical factors play the c entral role in the production of neurogenic trophic lesions and that m icrocirculatory dysfunction may be a marker for severe neurogenic oste oarthropathy rather than a causative factor.