Volume 58 No 3  Cover Story

Multiple cranial burr hole surgery is one of the indirect bypass surgeries used in moyamoya disease, but the exact mechanism is still uncertain. In this animal study, authors elucidated that bone marrow-derived stem cells (BMSCs) exist at the cortical incision site below a burr hole in ischemic rat brain, and angiogenesis and neurogenesis increased at the same area. This findings suggest that increased angiogenesis and neurogenesis by calvarial BMSCs may play some important role in the burr hole surgery for moyamoya disease.