Executive function and diffusion in frontal white matter of adults with moyamoya disease

Background: Cognitive impairment is a frequent complication of moyamoya disease (MMD) in adults. Chronic hypoperfusion in frontal lobes can lead to subtle brain injury, resulting in cognitive dysfunctions. Apparent diffusion coefficient (ADC) in normal-appearing white matter on conventional magnetic resonance imaging correlates with cerebral hemodynamics in the frontal lobe. Objective: The purpose of this study was to examine the relationship of ADC with executive function in patients with MMD. Methods: Thirty-one patients (25 women and 6 men; mean age, 32.6 ± 10.4 years) were included in this study. Executive function was evaluated by the Frontal Assessment Battery (FAB) at 21.5 ± 7.5 years after disease onset. ADC was measured in the normal-appearing frontal white matter. Results: ADC was statistically related to the occurrence of executive dysfunction in multivariate analysis (P =.0179). Total FAB score and ADC were negatively correlated (r² =.22; P =.0072; Spearman correlation coefficient, -.41; P =.024). Elevated ADC predicted executive dysfunction (area under the receiver operating characteristic curve,.73; 95% confidence interval,.55-.91; P =.029). Conclusions: The association of ADC with executive function might suggest that ADC is useful in screening for executive dysfunction during follow-up in the outpatient setting.