Abstract
Glycogen deposition in vascular smooth muscle has been demonstrated previously in alpha‐glucosidase deficiency but has not been clinically significant. Three sons of healthy, nonconsanguineous parents developed progressive proximal muscular weakness secondary to alpha‐glucosidase deficiency. Each patient developed a fusiform basilar artery aneurysm, which was complicated by fatal rupture in two patients and a cerebellar infarction in the third. Postmortem examination demonstrated severe vacuolation of skeletal muscle, liver, and vascular smooth muscle with accumulation of periodic acid‐Schiff–positive, diastase‐sensitive material. In the surviving brother, similar glycogen deposition was demonstrated in the smooth muscle of the superficial temporal artery. Basilar artery aneurysm formation in this sibship may be a consequence of alpha‐glucosidase deficiency. Copyright © 1987 American Neurological Association