106 Characteristics of Cognitive Impairment in Moyamoya Disease

INTRODUCTION: Cognitive impairment in adult moyamoya disease (MMD) is thought to be the result of ischemic stroke; however, the presence and extent of cognitive decline in asymptomatic patients remain largely unknown. METHODS: After classification using T2-weighted fluid attenuated inversion recovery (FLAIR) magnetic resonance imaging (MRI), a total of 19 MMD patients with a history of cerebral infarction, 21 asymptomatic MMD patients, and 20 healthy controls matched for age, sex, and years of education were prospectively included in this study. A detailed neuropsychological evaluation of two moyamoya subgroups and normal controls was conducted. In addition, participants underwent arterial spin labeling and resting state fMRI sequences. RESULTS: Asymptomatic patients showed varying degrees of decline in intelligence (Raven’s Standard Progressive Matrices, P = 0.001), spatial imagination (mental rotation, P = 0.014), working memory (verbal working memory-backward digit span, P = 0.011), and computational ability (simple subtraction, P = 0.014; complex subtraction, P < 0.001) compared with normal controls. MMD patients with cerebral infarction had more severe impairment in complex arithmetic (P = 0.027) and word short-term memory (P = 0.01) than those without symptoms. The asymptomatic MMD group also showed decreased CBF in the left anterior central and left inferior frontal gyri of the island fap with multiple node abnormalities in the brain network and reduced network connectivity. There was a significant association of these changes with cognitive decline in the MMD group. CONCLUSIONS: In asymptomatic MMD patients, a variety of cognitive impairments precedes the onset of clinical symptoms such as cerebral infarction, which may be a long-term complication of conservative treatment. Besides, disturbance of CBF and impaired brain network connections may be important causes of cognitive decline.