PAINFUL LUMBOSACRAL PLEXOPATHY WITH ELEVATED ERYTHROCYTE SEDIMENTATION-RATE - A TREATABLE INFLAMMATORY SYNDROME

Patients (6) had a syndrome of painful lumbosacral plexopathy with elevated erythrocyte sedimentation rate. Sural nerve biopsy in each case showed axonal degeneration and epineurial arterioles surrounded by mononuclear inflammatory cells. Differential fascicular involvement suggested an ischemic cause in 3 nerves, but no patient had a necrotizing vasculitis. None of the 6 patients had vasculitis or cancer. Of the 6 patients 3 were diabetic and were initially thought to have diabetic plexopathy, but deterioration continued despite control of the diabetes. These 6 patients appeared to have an ischemic neuropathy with an immunological basis. Five were treated with immunosuppressant drugs, and in 4 the plexopathy improved or was arrested. The pathogenesis is unclear, but postmortem findings in 1 case suggest that the syndrome does not stem from an underlying vasculitis.