Postoperative change of neuropsychological function after indirect revascularization in childhood moyamoya disease: a correlation with cerebral perfusion study

Functional and Neuropsychological Outcome After Surgical Treatment of Moyamoya Disease

BACKGROUND

Moyamoya disease (MMD) is a rare cerebrovascular disease characterized by progressive stenosis of the supraclinoid internal carotid artery. As a result of chronically decreased brain perfusion, eloquent areas of the brain become hypoperfused, leading to cognitive changes in patients. Repeated infarcts and bleeds produce clinically apparent neurologic deficits.

OBJECTIVES

1) To study the functional and neuropsychological outcome in MMD after revascularization surgery. 2) To find postrevascularization correlation between functional and neuropsychological improvement and radiologic improvement.

METHODS

A single-center prospective and analytic study was carried out including 21 patients with MMD during the study period from March 2021 to December 2022. Patients were evaluated and compared before and after revascularization for functional, neuropsychological, and radiologic status.

RESULTS

Postoperative functional outcome in terms of modified Rankin Scale score showed improvement in 33.33% of cases (P = 0.0769). An overall improving trend was observed in different neuropsychological domains in both adult and pediatric age groups. However, the trend of neuropsychological improvement was better in adults compared with pediatric patients. Radiologic outcome in the form of the Angiographic Outcome Score (AOS) significantly improved after revascularization (P = 0.0001). There was a trend toward improvement in magnetic resonance imaging (MRI) perfusion in the middle cerebral artery and anterior cerebral artery territories, 4.7% (P = 0.075) and 9.33% (P = 0.058) respectively, compared with preoperative MRI perfusion.

CONCLUSIONS

After revascularization, significant improvement occurred in functional and neuropsychological status. This result was also shown radiologically as evidenced by improvement in MRI perfusion and cerebral angiography.

Neuropsychiatric Symptoms of Moyamoya Disease: Considerations for the Clinician

Neurocognitive impairment in moyamoya disease is common, under recognized, and potentially devastating. The purpose of this paper is to provide an updated overview on this topic for the practicing clinician. We searched PubMed for keywords including cognitive impairment, neurocognitive dysfunction, and neuropsychological recovery in moyamoya disease. We summarized the literature to provide a concise review of the treatment and management of neuropsychiatric symptoms associated with moyamoya disease. Neuropsychiatric sequelae have conventionally been attributed to chronic cerebral hypoperfusion and/or stroke. Cognitive dysfunction in adults with moyamoya disease is most commonly in the form of impaired executive function, whereas intelligence is the predominant impairment in children with moyamoya disease. Pharmacotherapy for treatment of the neuropsychiatric symptoms associated with moyamoya disease is appropriate and can improve quality of life; however, careful consideration is needed to avoid adverse cerebrovascular events. It remains unclear as to whether surgical revascularization improves or stabilizes cognitive performance and outcomes. Additional prospective studies are warranted to better understand the long-term impact of revascularization on cognitive functioning in moyamoya disease.

Transcranial Doppler in Childhood Moyamoya: An Underutilized Tool?

BACKGROUND

Children with moyamoya are at high risk for incident and recurrent stroke. Transcranial Doppler (TCD) ultrasound is an attractive option to screen high-risk populations for moyamoya and to provide stroke risk stratification information due to its safety and cost-effectiveness. We used TCD to evaluate cerebral blood flow velocities in children with presurgical moyamoya and to determine if velocities differ between children with stable and unstable disease.

METHODS

Fourteen participants aged ≤21 years with a radiographic diagnosis of moyamoya or moyamoya-like arteriopathy underwent a research TCD at a median age of 7.2 years. TCDs were performed outside of the setting of acute stroke and before surgical revascularization. Arteriopathy was classified as unstable if the participant had a stroke or transient ischemic attack within three months preceding the TCD.

RESULTS

Middle cerebral artery and internal carotid artery (ICA) blood flow velocities were elevated. The median M1 velocity was 138 cm/s (interquartile range [IQR] 106 to 168). Individual M1 flow velocities were a median of 5.0 S.D.s above age-based normative values. The median distal ICA velocity was 146 cm/s (IQR 124 to 163). Individual ICA flow velocities were a median of 5.9 S.D.s above normative values. Participants with unstable arteriopathy had higher M1 velocities compared with those with stable arteriopathy (170 vs 119 cm/s, P = 0.0003). We did not identify velocity differences based on comorbid conditions or age.

CONCLUSIONS

These preliminary data suggest that TCD is a promising tool for screening for cerebral arteriopathies in high-risk pediatric populations and assessment for unstable disease.

Post-Surgical Cognitive Outcomes of Moyamoya Disease: A Systematic Review

BACKGROUND

Moyamoya disease (MMD) is an occlusive arteriopathy leading to stroke. Progressive if left untreated, revascularization surgery has become the mainstay of treatment. Although clinical and radiographic outcomes of MMD after intervention are well-characterized, cognitive outcomes in pediatric patients remain unclear. We aimed to examine postoperative cognitive outcomes in children with MMD, examine factors associated with cognitive changes after intervention, and define the effect of revascularization surgery on cognitive outcomes.

METHODS

A systematic review was conducted following PRISMA guidelines searching PubMed, Embase, and Scopus databases. Articles met inclusion criteria if they studied pediatric patients undergoing revascularization surgery for MMD and examined cognitive outcomes either qualitatively or quantitatively. All data extracted from included articles was examined descriptively.

RESULTS

Of 1091 resultant articles, 12 articles containing 446 patients were included. Surgery was associated with maintained or improved full scale intellectual quotient (IQ), performance IQ, perceptual IQ, memory quotient and verbal memory. However, 70% of patients had impaired cognitive function, with associated poor school performance. Improvements in cognition were associated with increased cerebral blood flow, particularly to the middle cerebral artery, due to the development of collaterals. Female sex, shorter duration from symptom onset to surgery, and surgery after age 7 were predictive of cognitive improvement. Completed ischemic stroke prior to surgery was associated with poorer cognitive outcomes.

CONCLUSIONS

Although children with MMD have improved cognitive outcomes following revascularization overall, a distinct subset experience cognitive impairment. Consideration of patient-specific and treatment-related factors is important to enable proper risk stratification and inform management approaches.

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

Background: It remains unclear whether revascularization of moyamoya vasculopathy (MMV) has a positive effect on cognitive function. In this prospective, single-center study, we investigated the effect of revascularization on cognitive function in patients with MMV. We report clinical and radiological outcome parameters and the associations between clinical determinants and change in neurocognitive functioning. Methods: We consecutively included all MMV patients at a Dutch tertiary referral hospital who underwent pre- and postoperative standardized neuropsychological evaluation, [15O]H2O-PET (including cerebrovascular reactivity (CVR)), MRI, cerebral angiography, and completed standardized questionnaires on clinical outcome and quality of life (QOL). To explore the association between patient characteristics, imaging findings, and change in the z-scores of the cognitive domains, we used multivariable linear- and Bayesian regression analysis. Results: We included 40 patients of whom 35 (27 females, 21 children) were treated surgically. One patient died after surgery, and two withdrew from the study. TIA- and headache frequency and modified Rankin scale (mRS) improved (resp. p = 0.001, 0.019, 0.039). Eleven patients (seven children) developed a new infarct during follow-up (31%), five of which were symptomatic. CVR-scores improved significantly (p < 0.0005). The language domain improved (p = 0.029); other domains remained stable. In adults, there was an improvement in QOL. We could not find an association between change in imaging and cognitive scores. Conclusion: In this cohort of Western MMV patients, TIA frequency, headache, CVR, and mRS improved significantly after revascularization. The language domain significantly improved, while others remained stable. We could not find an association between changes in CVR and cognitive scores.

Progression in Moyamoya Disease: Clinical Feature, Neuroimaging Evaluation and Treatment

Moyamoya disease (MMD) is a chronic cerebrovascular disease characterized by progressive stenosis of the arteries of the circle of Willis, with the formation of collateral vascular network at the base of the brain. Its clinical manifestations are complicated. Numerous studies have attempted to clarify the clinical features of MMD, including its epidemiology, genetic characteristics, and pathophysiology. With the development of neuroimaging techniques, various neuroimaging modalities with different advantages have deepened the understanding of MMD in terms of structural, functional, spatial, and temporal dimensions. At present, the main treatment for MMD focuses on neurological protection, cerebral blood flow reconstruction, and neurological rehabilitation, such as pharmacological treatment, surgical revascularization, and cognitive rehabilitation. In this review, we discuss recent progress in understanding the clinical features, in the neuroimaging evaluation and treatment of MMD.

Ischemic sequelae and other vascular diseases

Although pediatric stroke is associated with higher survival rates compared with adult stroke, a substantial body of evidence indicates significant neuropsychologic morbidity in pediatric stroke survivors. Neuroplasticity does not guarantee good outcome in children. The general trends observed in the literature are reviewed as is the profile observed in common causes of pediatric stroke: congenital heart disease, moyamoya disease, and sickle cell disease. The neuropsychologic profile of pediatric stroke patients is heterogeneous due to the multiplicity of associated causes. Stroke in early infancy and large strokes are associated with cognitive impairment while more limited disorders, such as phasic deficit, are observed in childhood stroke. Executive dysfunction is common in pediatric stroke, but social interaction skills are usually preserved. Congenital heart disease and sickle cell disease are associated with global neuropsychologic dysfunction while cognition is usually preserved in moyamoya. Executive dysregulation is instead more frequently reported in this population. Further study of maladaptive processes after pediatric stroke will allow identification of predictors of functional and neuropsychologic outcomes and permit personalization of care.