Objectives: Ischemic stroke is a frequent manifestation in patients with adult moyamoya disease (MMD), but the relationship between the lesion pattern and disease severity has rarely been investigated.
Methods: We collected data on a consecutive series of 65 adult MMD patients who visited our hospital between 1999 and 2006. Among them, 32 patients with first-ever ischemic stroke were included. The ischemic lesions were categorized by location and compared as follows: 1) cortical vs subcortical involvement and 2) anterior (fronto-temporal) vs. posterior (parieto-occipital) involvement. The lesions were also compared by disease severity as determined by the extent of intracranial artery involvement (Suzuki's grading method) and by the perfusion status visualized on single photon emission computed tomography (SPECT).
Result: The disease severity was significantly greater in patients with cortical involvement than in those with subcortical involvement (Suzuki's grade, 4.17±0.72 vs. 2.70±0.73, p<0.001). The disease severity was also significantly greater in patients with posterior involvement than in those with anterior involvement (4.50±0.53 vs. 2.83±0.76, p<0.001). In most of the patients (83.3%) the perfusion defect area shown on SPECT was larger than the ischemic lesion area shown on MRI.
Conclusions: We found that patients with advanced stage adult MMD tended to have ischemic lesions involving the cortex and posterior part of the brain and that the stroke mechanism in these patients was largely associated with hemodynamic compromise. Our results suggest that the lesion pattern of ischemic stroke may change along with the extent of arterial involvement.