Decreased frontal white-matter diffusion and improved cognitive flexibility after burr-hole surgery in moyamoya angiopathy

Abstract

Background In Moyamoya Angioplasty (MMA), increased apparent diffusion coefficient (ADC) in frontal white matter (WM) with a normal appearance has been associated with frontal hypoperfusion and executive dysfunction. Multiple burr-hole surgery enables the revascularization of large frontal areas. Goal: To assess the effect of multiple burr-hole surgery on the ADC and cognitive functions in adults with MMA. Methods ADC was measured in 26 brain hemispheres of 14 consecutive adults with MMA (9 women, mean age ± SD: 38.1 ± 10.7 years) prior to and 6 months after burr-hole surgery. ADC was obtained from regions of interest located in frontal and posterior (temporo-occipital) normal-appearing WM. Ten patients had neuropsychological assessment that focused on executive and attentional functions before and after surgery. Results Anterior and posterior ADC values did not differ before surgery (815.8 ± 60.1 vs. 812.1 ± 35.3 mm2/s, p = 0.88). After surgery, frontal ADC was lower than prior to surgery (789.9 ± 64.5 vs. 815.8 ± 60.1 mm2/s; p <0.001) whereas no change occurred in posterior ADC (p = 0.31). Trail-making test part B median z-score increased from − 1.47 to − 0.21 (p = 0.018), suggesting improved cognitive flexibility. Conclusion In adults with MMA, indirect revascularization with burr-hole is followed by a decrease of ADC in normal-appearing frontal WM and may have improved some executive functions in the flexibility process. Change in ADC may reflect the improvement in cerebral perfusion after surgery. The measuring of ADC may be a promising tool in exploring potentially reversible microstructural WM damage related to hypoperfusion and cognitive change in MMA.

Clinical Outcome, Cognition, and Cerebrovascular Reactivity after Surgical Treatment for Moyamoya Vasculopathy: A Dutch Prospective, Single-Center Cohort Study

“…Previous studies reported mortality ranges between 0.86% [22] and 1.86% [23]. Overall adverse postoperative events (mainly ischemic and hemorrhagic stroke) are reported to be between 5-14% [22][23][24] in MMV, consistent with our results. Remarkably, the only randomized controlled surgical trial in MMD comparing STA-MCA bypass surgery to conservative treatment in adults who presented with hemorrhage reported not a single perioperative adverse event after 84 operations [25].…”

“…One Western study showed that-although there was no improvement in CVR-there was some improvement in executive functioning [24]. The difference in CVR change could be explained by the burr-hole technique used, possibly leading to a slower increase in hemodynamic functioning than the combined direct-indirect technique we used.…”

Neuropsychology of Moyamoya Disease

“…Multiple burr-hole surgery enables the revascularization of large frontal areas. In this sense, Calviere et al recently assessed the effect of such surgery on the ADC and cognitive functions in fourteen adults treated with angioplasty before and six months after the intervention [68]. ADC was obtained from regions of interest located in frontal and posterior (temporo-occipital) normal-appearing WM.…”

Long-Term Cognitive Changes after Revascularization Surgery in Adult Patients with Ischemic Moyamoya Disease

“…Revascularization surgery in adult MMD changes cognitive function and prevents further cerebral ischemic events [ 6 , 11 , 12 , 13 , 14 , 15 ]. Most adult MMD patients who undergo revascularization surgery do not show cognitive changes relative to cognitive ability before surgery, although some patients do demonstrate improved or worsened cognitive function postoperatively [ 16 ].…”

“…Most of these studies however repeated neuropsychological evaluation within 1 year after surgery [ 10 , 11 , 13 , 14 , 15 , 16 ]. Only 1 study performed neuropsychological testing >1 year but <2 years postoperatively [ 12 ].…”