De Novo Cerebral Microbleeds and Cognitive Decline in Cerebral Hyperperfusion After Direct Revascularization for Adult Moyamoya Disease

Cognitive dysfunction in Moyamoya disease: latest developments and future directions

Cognitive dysfunction is common in Moyamoya disease (MMD). However, current knowledge of cognitive impairment in MMD is inadequate. In this review, we explored the characteristics of altered cognitive function associated with MMD and offered recommendations aimed at guiding potential research endeavors into the cognitive dysfunction in MMD. Cognitive functions, including executive function, intelligence, memory and so on, show characteristic declines in MMD. The effects of cerebral revascularization surgery on cognitive impairment are controversial. Currently, there is still a lack of relevant research on cognitive impairment. Research on the pathogenesis and etiology associated with Moyamoya disease as well as long-term cohort studies, are important future directions.

The Recipient Vessel Hemodynamic Features Affect the Occurrence of Cerebral Edema in Moyamoya Disease After Surgical Revascularization: A Single-Center Retrospective Study

Objective

In moyamoya disease (MMD) with direct or combined revascularization, the initially hemodynamic recipient features are likely one of the main causes of acute hemodynamic disruption. Previous studies have explored the relationship between recipient diameter or flow velocity and postoperative complications, but there are still no optimal selection criteria with multiple potential recipient vessels. Cerebral edema is one of the most common radiological manifestations in the acute postoperative period. This study assessed the hemodynamic characteristics of cortex vessels related to postoperative cerebral edema.

Methods

All patients who had undergone direct or combined revascularization with preoperative digital subtraction angiography (DSA) between 2019 and 2021 were eligible for inclusion in this study. The application of DSA was performed and regular radiological examinations were employed after surgery. DSA was analyzed with the hemodynamic features within chosen recipient vessels. Cerebral edema was identified as a low-density image on CT or high signaling in the MRI T2 phase. The recipient hemodynamic characteristics and demographic presentation, as well as clinical data, were retrospectively analyzed in this study.

Results

A total of 103 patients underwent direct or combined revascularization with preoperative DSA. The mean age of this enrolled cohort was 44.31 ± 10.386 years, in which bilaterally involved MMD accounted for the main part. The preliminary correlation analysis found preoperative disease period (p = 0.078), recipients observed in angiography (p = 0.002), and surgery on the left (p = 0.097) may be associated with cerebral edema. The following regression analysis confirmed low occurrence of cerebral edema was accompanied by recipients observed in angiography (p = 0.003). After subdividing by flow direction and hemodynamic sources, the incidence rate of anterograde direction, anterior sources, and posterior sources were significantly lower than undetected recipients.

Conclusions

Cerebral edema is a common radiological manifestation in MMDs after surgery. In this study, the observation in angiography reliably identifies a variety of physiological or pathological recipient detection, flow direction, and hemodynamic sources in patients with MMD after revascularization, which indicates the selection strategy of potential recipients and highlights the importance of recipient observability in DSA. Meanwhile, vascular conditions determined by recipient hemodynamics meditate the occurrence of postoperative cerebral edema.

Angiographic, Cerebral Hemodynamic, and Cognitive Outcomes of Indirect Revascularization Surgery Alone for Adult Patients With Misery Perfusion due to Ischemic Moyamoya Disease

BACKGROUND

Revascularization surgery for adult patients with ischemic moyamoya disease (MMD) may improve both cognitive function and cerebral perfusion.

OBJECTIVE

To determine angiographic, cerebral hemodynamic, and cognitive outcomes of indirect revascularization surgery alone for adult patients with misery perfusion due to ischemic MMD (IDR group) and to test the superiority of indirect revascularization surgery for cognitive improvement by conducting comparisons with historical control patients who had undergone direct revascularization surgery (DR group) through prospective cohort study with historical controls.

METHODS

Twenty adult patients with cerebral misery perfusion underwent encephalo-duro-myo-arterio-pericranial-synangiosis alone. Cerebral angiography through arterial catheterization, brain perfusion single-photon emission computed tomography, and neuropsychological testing were performed preoperatively and at 6 months postoperatively.

RESULTS

In 17 patients of the IDR group, collateral flows that were newly formed after surgery on angiograms fed more than one-third of the middle cerebral artery (MCA) cortical territory. In the IDR group, perfusion in the MCA territory was significantly increased after surgery (P < .0001), and the difference in MCA perfusion between before and after surgery was significantly greater (P = .0493) compared with the DR group. Improved cognition was significantly more frequent in the IDR group (65%) than in the DR group (31%, P = .0233).

CONCLUSION

Indirect revascularization surgery alone forms sufficient collateral circulation, improves cerebral hemodynamics, and recovers cognitive function in adult patients with misery perfusion due to ischemic MMD. The latter 2 beneficial effects may be higher when compared with patients undergoing direct revascularization surgery.