Regional migratory osteoporosis. A denervation disease.

Regional migratory osteoporosis is an uncommon entity charcterized by sudden attacks of migrating lower extremity paraarticular pain, local edema, and muscle atrophy; the disease is verified by radiologic demineralization and bone scan uptake. The etiology and pathogenesis are unknown. We describe a case of regional migratory osteoporosis followed over nine years by serial electromyographic studies documenting denervation patterns coincident in time and location of each acute attack. The substantiation of denervation in regional migratory osteoporosis is of both diagnostic and pathogenetic significance.