To explore whether moyamoya vessels based on digital subtraction angiography (DSA) could be used to predict cognitive dysfunction for adults with moyamoya disease (MMD).

From December 2018 to June 2019, 43 adult cases of MMD were admitted to the Beijing Tiantan Hospital, Capital Medical University (MMD group); and 22 patients undergoing physical examination who matched the gender, age and education level were included as a healthy control group. Both groups were required to take cognitive assessment, including Webster's adult intelligence scale (WAIS) test, prospective memory (PM) test, repeatable battery neuropsychological status (RBANS), Stroop test, Wisconsin card sorting test (WCST), and trail making test A (TMT-A). The participant was diagnosed with cognitive dysfunction when three or more cognition tests were abnormal. Moreover, MMD patients were examined by DSA and evaluated by an experienced neurosurgeon. According to the density of smoke vessels in the left cerebral hemisphere, patients with MMD were divided into "none" (11 cases), "sparse" (20 cases), and "dense" (12 cases) subgroups whose cognitive function were compared.

Fourteen of the 43 adult MMD patients (32.6%) had cognitive dysfunction. When comparing MMD patients with and without cognitive dysfunction, significant difference in smoke vessels arising from left hemisphere could be found (P=0.007). Correlation analysis (excluding patients with "none" smoke vessel subgroup) had shown that there was a moderate correlation between cognitive dysfunction and smoke vessels (r=-0.522, P=0.002). Quantitative analysis of cognitive function based on the density of smoke vessels in left cerebral hemisphere showed that there were significant differences in the event based prospective memory (EBPM), PM, word interference of Stroop test, categories completed of WCST and TMT-A (P＜0.05). Based on the comparison of cognitive function among three subgroups, significant differences were present in EBPM, PM, WCST-CC, and TMT-A between "none" and "sparse" subgroups. However, significant difference could only be found in time based prospective memory, word interference and TMT-A between "sparse" and "dense" subgroup.

Smoke vessels arising from the left hemisphere could predict the cognitive dysfunction for adult MMD patients without surgery. The more moyamoya vessels, the less cognitive dysfunction. Cognitive dysfunction in "sparse" subgroup was the most serious, especially in PM and executive function. Therefore, "potential of moyamoya vascularization" might be an important sign of cognitive function in adults with MMD.