The distribution patterns of cerebral infarction and the features of collateral circulation in adult patients with ischemic moyamoya disease

Objective: To investigate the distribution patterns of cerebral infarction and the features of collateral circulation in adult patients with ischemic moyamoya disease. Methods: During the period from Jan. 2009 to Dec. 2012, a total of 34 patients with acute cerebral infarction due to moyamoya disease were admitted to authors' hospital. MRI and cerebral DSA were performed in all patients. Diffusion-weighted imaging (DWI) findings confirmed the diagnosis of acute cerebral infarction. The distribution patterns of cerebral infarction and the features of collateral circulation were analyzed. The relationship between the collateral circulation and the vascular grades was statistically analyzed. Results: DWI showed that 42 cerebral hemispheres were involved in 34 patients with acute cerebral infarction. The infarction patterns included cortical infarction (71.4%), watershed infarction (71.4%) and perforating artery infarction (23.8%). According to Mugikura 4-stage classification (I-IV stage), on DSA stage I was seen in 9 cerebral hemispheres (21.43%), stage II in 17 cerebral hemispheres (40.47%), stage III in 8 cerebral hemispheres (19.05%) and stage IV in 8 cerebral hemispheres (19.05%). According to the related literature, the collateral circulations were divided into 3 grades. Grade I collateral circulation seen in stage I to V groups was 8 (34.7%), 11 (47.8%), 3 (13.1%) and 1 (4.4%), respectively. The difference between each other among the four groups was statistically significant (Z = -2.763, P = 0.006). Grade I collateral circulation seen in stage I to V groups was 4 (13.3%), 12 (41.4%), 7 (24.1%) and 6 (20.7%), respectively. No significant difference existed between each other among the four groups (Z = -1.684, P = 0.092). Grade III collateral circulation seen in stage I to IV groups was 0 (0%), 0 (0%), 1 (33.3%) and 2 (66.7%), respectively. The difference between each other among the four groups was statistically significant (Z = -2.299, P = 0.021). Conclusion: The main distribution patterns of cerebral infarction in patients with ischemic moyamoya disease are cortical infarction and watershed infarction, indicating that artery-to-artery embolism and hypoperfusion/impaired emboli clearance may act together in the development of the disease. The pattern of collateral circulation varies with the development of moyamoya disease. Grade I and II collateral circulations are commonly seen in the middle stage of the disease, while Grade III collateral circulations are usually seen in the advanced stage. (authors)