Moyamoya disease in patients of Finno-Ugric origin.

The terms moyamoya disease, moyamoya syndrome and moyamoya phenomenon can be found dispersed throughout the literature. The diagnostic criteria for moyamoya disease are: (1) stenosis or occlusion of the anterior cerebral, middle cerebral and internal carotid arteries, (2) an abnormal vascular network near these arteries and (3) bilateral findings. When only the two first conditions are present, the term moyamoya syndrome is used. The incidence of moyamoya disease is high in the Mongol race, although the moyamoya syndrome is more frequently reported among Caucasians. In the last two decades 41 cases of moyamoya were diagnosed in two Hungarian and two Scandinavian hospitals, respectively. Thirty-one patients were operated on 12 unilaterally and 19 bilaterally--either with extracranial/intracranial bypass (29 cases) or with encephalomyosynangiosis (2 cases). After a mean follow-up of seven years, 67.7% of the operated cases were symptom-free or neurologically improved. The majority of the patients had moyamoya disease and turned out to be of Finno-Ugric or Lapplandish ancestry. These people originally migrated from the East and belong to the Ural-Altaic family. Our findings suggest that while the moyamoya syndrome is found in different races, the moyamoya disease may be limited to people of Eastern (Mongol) origin. Revascularization surgery may be of benefit to patients with moyamoya.