Background and purpose The pattern of infarctions based on the findings of diffusion-weighted image was assessed, and it was also investigated whether there are any age-specific differences in patients with moyamoya disease (MMD).

Methods The subjects were 66 consecutive patients with MMD who had an acute cerebral infarction. Each ischaemic lesion was categorised into one of seven patterns (gyral, atypical territorial, honeycomb, classic territorial, multiple-dot, borderzone, deep lacunar) based on diffusion-weighted image findings. The patterns were compared between adulthood-onset MMD (A-MMD, ≥20 years old, 34 patients) and childhood/adolescent-onset MMD (C-MMD, <20 years old, 32 patients) according to their ages of infarct presentation.

Results A total of 91 infarct patterns were observed from 66 patients. The gyral, atypical territorial, and honeycomb patterns, which are not usually seen in conventional stroke patients, were common in MMD (68.1%). Among all patterns, a gyral pattern was most common (40/91, 44.0%). Borderzone and deep lacunar patterns were infrequent. Gyral and borderzone patterns were more frequently seen in the C-MMD group, whereas a honeycomb pattern was not seen in young patients. Honeycomb pattern was more common at advanced vascular stages. Infarctions confined to the cortex were more common in the C-MMD group (26/32, 75.0%) than in A-MMD patients (14/34, 41.2%).

Conclusions Moyamoya disease showed various characteristic and age-specific infarct patterns. Different infarct patterns between the A-MMD and C-MMD groups may be associated with age-specific vulnerability of the brain to ischaemia, stage of arteriopathy or changes of abnormal collateral pathways.