Postoperative executive function in adult moyamoya disease: a preliminary study of its functional anatomy and behavioral correlates

Abstract

OBJECTIVE Chronic frontal hemodynamic disturbances are associated with executive dysfunction in adult patients with moyamoya disease (MMD). However, the impact of surgical revascularization on executive dysfunction and its underlying mechanism remains unclear. The aim of the present study was to examine the postoperative radiological correlates of cognitive improvement and thereby explore its underlying mechanism. METHODS Fourteen patients who met the inclusion criteria were identified at Huashan Hospital, were operated on, and were successfully followed up for 6 months. Postoperative changes in cortical perfusion and regional amplitude of low-frequency fluctuations (ALFF) were examined by SPECT and resting-state functional MRI, respectively. Executive function was evaluated by 2 tests (Trail Making Test Part B and the summation of executive subtests of Memory and Executive Screening [MES-EX]). Follow-up neuropsychological outcomes were then correlated with radiological changes to identify nodes functioning as leading contributors to postoperative executive outcomes. RESULTS All patients underwent successful unilateral bypass procedures, with some operations performed on the left side and some on the right side. At the 6-month follow-up, the baseline and follow-up test scores for the different sides did not differ significantly. The group with good collaterals (Matsushima Grade A, 9 patients) exhibited significantly increased postoperative perfusion (change in [△] hemodynamics) in bilateral frontal (left, p = 0.009; right, p = 0.003) and left parietal lobe (p = 0.014). The Spearman's correlation test suggested that only the right frontal lobe exhibited significant positive postoperative radiological correlates with cognitive performance (△MES-EX vs △hemodynamics, r = 0.620, p = 0.018; △MES-EX vs △ALFF, r = 0.676, p = 0.008; △hemodynamics vs △ALFF, r = 0.547, p = 0.043). Subsequent regional ALFF analysis revealed that the right dorsolateral prefrontal cortex (DLPFC) was the only node in the responsible hemisphere to exhibit significant postoperative changes. CONCLUSIONS The results not only advance our understanding of pathological interactions of postoperative executive performance in adult MMD, but also indicate that the right DLPFC amplitude might be a quantitative predictor of postoperative executive control improvement.

Cognitive Performance Profile in Pediatric Moyamoya Disease Patients and Its Relationship With Regional Cerebral Blood Perfusion

“…Anatomical location of advanced cognitive function has undergone intensive investigation. Despite a few studies reporting a correlation between hemodynamic compromise in temporal lobe and cognitive impairment (26,30), more researchers found that regions in the frontal lobe are linked to executive function, both from aspects of hemodynamics and metabolism (4,15,31,32). Using multivariate linear regression to adjust for confounders, we found that the average CBF of the left temporal lobe independently associated with processing speed.…”

Mapping altered brain connectivity and its clinical associations in adult moyamoya disease: A resting-state functional MRI study

“…Cognitive dysfunction resulting from MMD has begun to garner the attention of researchers studying the disorder [ 14 , 15 , 18 ]. However, despite the increasing use of rs-fMRI to investigate brain function in other cognitive disorders, few published studies have used rs-fMRI to investigate cognitive dysfunction in MMD, [ 17 , 20 , 23 ]. In this study, we conducted rs-fMRI in a group of patients with MMD who had minimal ischemic lesions and no prior history of revascularization surgery, because such patients require early detection of ischemic brain injury.…”

“…Such research has revealed several patterns of brain function associated with MMD. For example, the averaged square root of power maps of low-frequency BOLD signals was found to identify disease-related changes in patients with MMD and predict postsurgical cognitive improvement [ 17 , 20 ]. Furthermore, attenuated local synchronization of low-frequency BOLD signals has been associated with worse cognitive performance in patients with MMD [ 17 ].…”

“…For example, the averaged square root of power maps of low-frequency BOLD signals was found to identify disease-related changes in patients with MMD and predict postsurgical cognitive improvement [ 17 , 20 ]. Furthermore, attenuated local synchronization of low-frequency BOLD signals has been associated with worse cognitive performance in patients with MMD [ 17 ]. Although conventional rs-fMRI analysis is performed by using the temporal correlations of low-frequency BOLD signals, profiles of this parameter have not been sufficiently reported in patients with MMD.…”

“…However, the extent of alterations in low-frequency BOLD signals associated with vascular lesions and rCBF has not been clearly demonstrated. Furthermore, the clinical significance of such alterations has not been determined in relation to ischemic symptoms or cognitive performance [ 17 , 23 ]. Thus, elucidating pattern of connectivity measured with rs-fMRI is worthwhile because this novel technique offers a potentially feasible method to assess multiple brain systems and could provide additional information beyond cerebral perfusion as part of routine clinical investigations.…”