Tubular aggregates in a case of osteomalacic myopathy due to anticonvulsant drugs.

We describe a case of severe osteomalacia and secondary myopathy due to anticonvulsant drugs--barbiturates and phenytoin. The clinical course of the patient, a 29-year-old epileptic woman subject to anorexia, demonstrates the importance of alimentary intake in the pathogenesis of the disease. Muscle biopsy performed before and after treatment showed the efficacy of therapy with 25-hydroxy cholecalciferol. However, in both biopsies tubular aggregates were found: this unusual ultrastructural finding probably indicates the direct action of the anticonvulsant drugs on the sarcoplasmic reticulum membranes. This is the second case of osteomalacic myopathy due to anticonvulsants confirmed by histologic and ultrastructural examinations; it is also the first report of tubular aggregates in this muscular disease.