Two-Year Clinical, Cerebral Hemodynamic, and Cognitive Outcomes of Adult Patients Undergoing Medication Alone for Symptomatically Ischemic Moyamoya Disease Without Cerebral Misery Perfusion: A Prospective Cohort Study

Medical Management of Adult Moyamoya Disease: A Review and Relevant Cases With Ischemic Events

Moyamoya disease (MMD) is a rare and progressive cerebrovascular disorder characterized by stenosis or occlusion of the internal carotid arteries resulting in the development of fragile collateral vessels at the base of the brain. Surgical revascularization is the primary treatment option for preventing ischemic and hemorrhagic events; however, the role of medical management has become increasingly recognized, particularly in cases involving asymptomatic patients or those at a high risk for surgical complications. In this review, we aimed to investigate the current guidelines and evidence supporting various medical management strategies for MMD, including the importance of controlling risk factors and judicious use of antithrombotic therapy. Given the considerable variability in patient presentation, such as age of onset, symptomatology, and comorbid conditions, it is crucial to adopt tailored therapeutic approaches that address each patient's unique characteristics. The existing literature on medical management is limited. However, individualized strategies may effectively mitigate the risk of ischemic events and improve the overall patient outcomes. Further research is essential to develop comprehensive and standardized treatment protocols for medical management of adult patients with MMD. In addition, ongoing trials and efforts to develop disease-modifying agents are discussed.

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.

RNF213 variant and autophagic impairment: A pivotal link to endothelial dysfunction in moyamoya disease

Moyamoya disease (MMD) is closely associated with the Ring Finger Protein 213 (RNF213), a susceptibility gene for MMD. However, its biological function remains unclear. We aimed to elucidate the role of RNF213 in the damage incurred by human endothelial cells under oxygen-glucose deprivation (OGD). We analyzed autophagy in peripheral blood mononuclear cells (PBMCs) derived from patients carrying either RNF213 wildtype (WT) or variant (p.R4810K). Subsequently, human umbilical vein endothelial cells (HUVECs) were transfected with RNF213 WT (HUVECWT) or p.R4810K (HUVECR4810K) and exposed to OGD for 2 h. Immunoblotting was used to analyze autophagy marker proteins, and endothelial function was analyzed by tube formation assay. Autophagic vesicles were observed using transmission electron microscopy. Post-OGD exposure, we administered rapamycin and cilostazol as potential autophagy inducers. The RNF213 variant group during post-OGD exposure (vs. pre-OGD) showed autophagy inhibition, increased protein expression of SQSTM1/p62 (p < 0.0001) and LC3-II (p = 0.0039), and impaired endothelial function (p = 0.0252). HUVECR4810K during post-OGD exposure (versus pre-OGD) showed a remarkable increase in autophagic vesicles. Administration of rapamycin and cilostazol notably restored the function of HUVECR4810K and autophagy. Our findings support the pivotal role of autophagy impaired by the RNF213 variant in MMD-induced endothelial cell dysfunction.

Impact of Cerebral Revascularization on Pial Collateral Flow in Patients With Unilateral Moyamoya Disease Using Quantitative Magnetic Resonance Angiography

BACKGROUND AND OBJECTIVES

Moyamoya disease (MMD) is a chronic steno-occlusive disease of the intracranial circulation that depends on neoangiogenesis of collateral vessels to maintain cerebral perfusion and is primarily managed with cerebral revascularization surgery. A quantitative assessment of preoperative and postoperative collateral flow using quantitative magnetic resonance angiography with noninvasive optimal vessel analysis (NOVA) was used to illustrate the impact of revascularization on cerebral flow distribution.

METHODS

A retrospective review of patients with unilateral MMD who underwent direct, indirect, or combined direct/indirect cerebral revascularization surgery was conducted between 2011 and 2020. Using NOVA, flow was measured at the anterior cerebral artery (ACA), ACA distal to the anterior communicating artery (A2), middle cerebral artery (MCA), posterior cerebral artery (PCA), and PCA distal to the posterior communicating artery (P2). Pial flow (A2 + P2) and collateral flow (ipsilateral [A2 + P2])-(contralateral [A2 + P2]) were measured and compared before and after revascularization surgery. Total hemispheric flow (MCA + A2 + P2) with the addition of the bypass graft flow postoperatively was likewise measured.

RESULTS

Thirty-four patients with unilateral MMD underwent cerebral revascularization. Median collateral flow significantly decreased from 68 to 39.5 mL/min ( P = .007) after bypass. Hemispheres with maintained measurable bypass signal on postoperative NOVA demonstrated significant reduction in median collateral flow after bypass ( P = .002). Median total hemispheric flow significantly increased from 227 mL/min to 247 mL/min ( P = .007) after bypass. Only one patient suffered an ipsilateral ischemic stroke, and no patients suffered a hemorrhage during follow-up.

CONCLUSION

NOVA measurements demonstrate a reduction in pial collateral flow and an increase in total hemispheric flow after bypass for MMD, likely representing a decrease in leptomeningeal collateral stress on the distal ACA and PCA territories. Further studies with these measures in larger cohorts may elucidate a role for NOVA in predicting the risk of ischemic and hemorrhagic events in MMD.

Oxygen extraction fraction (OEF) values and applications in neurological diseases

One of the goals of this systematic review is to provide a meta-analysis-derived mean OEF of healthy volunteers. Another aim of this study is to indicate the OEF ranges of various neurological pathologies. Potential clinical applications of OEF metrics are presented. Peer-reviewed studies reporting OEF metrics derived from computed tomography (CT)/positron emission tomography (PET) and/or magnetic resonance imaging (MRI) were considered. Databases utilized included MEDLINE, PubMed, EMBASE, Web of Science, and Google Scholar. The Newcastle-Ottawa scoring system was used for evaluating studies. R Studio was utilized for the meta-analysis calculations when appropriate. The GRADE framework was utilized to assess additional findings. Of 2267 potential studies, 165 met the inclusion criteria. The healthy volunteer meta-analysis included 339 subjects and found a mean OEF value of 38.87 (37.38, 40.36), with a prediction interval of 32.40-45.34. There were no statistical differences in OEF values derived from PET versus MRI. We provided a GRADE A certainty rating for the use of OEF metrics to predict stroke occurrence in patients with symptomatic carotid or cerebral vessel disease. We provided a GRADE B certainty rating for monitoring treatment response in Moyamoya disease. Use of OEF metrics in diagnosing and/or monitoring other conditions had a GRADE C certainty rating or less. OEF might have a role in diagnosing and monitoring patients with symptomatic carotid or cerebral vessel disease and Moyamoya disease. While we found insufficient evidence to support measuring OEF metrics in other patient populations, in many cases, further studies are warranted.

Long-Term Resveratrol Intake for Cognitive and Cerebral Blood Flow Impairment in Carotid Artery Stenosis/Occlusion

BACKGROUND AND PURPOSE

Carotid artery stenosis or occlusion (CASO) is a causative disease of vascular cognitive impairment (VCI) attributed to cerebral hypoperfusion, even without the development of symptomatic ischemic stroke. Preclinically, resveratrol has been demonstrated to play an important role in improving cognitive function in rodent CASO models. This study investigated the association between long-term resveratrol intake and improvements in cognitive and cerebral hemodynamic impairments in patients with CASO.

METHODS

A retrospective cohort study was conducted on patients with asymptomatic carotid artery stenosis of ≥50% or occlusion who underwent 15O-gas positron emission tomography (15O-gas PET) and neuropsychological tests such as Montreal Cognitive Assessment (MoCA) and Alzheimer's Disease Assessment Scale-Cognitive Subscale 13 (ADAS-Cog) twice between July 2020 and March 2022 allowing >125-day interval. Patients were administered 30 mg/day resveratrol after the first 15O-gas PET and neuropsychological tests were compared with those who were not.

RESULTS

A total of 79 patients were enrolled in this study; 36 received resveratrol and 43 did not. Over a mean follow-up of 221.2 and 244.8 days, long-term resveratrol treatment significantly improved visuospatial/executive function (P=0.020) in MoCA, and memory domain (P=0.007) and total score (P=0.019) in ADAS-Cog. Cerebral blood flow demonstrated improvement in the right frontal lobe (P=0.027), left lenticular nucleus (P=0.009), right thalamus (P=0.035), and left thalamus (P=0.010) on 15O-gas PET. No adverse events were reported.

CONCLUSION

Long-term daily intake of oral resveratrol may prevent or treat VCI by improving the cerebral blood flow in asymptomatic patients with CASO.

Influence of atherosclerotic burden on adult patients with ischemic moyamoya disease: combined analysis of two prospective cohorts

OBJECTIVE

This study aimed to determine the influence of atherosclerotic risk factors on initial and further cerebrovascular events in adult patients with moyamoya disease (MMD) by combined analysis of two prospective cohorts in which patients received pharmacotherapy alone and were prospectively followed-up for 5 years.

METHODS

In 71 patients, smoking status, home blood pressure, hemoglobin (Hb)A1c and low-density lipoprotein cholesterol (LDL-chol) were checked at inclusion and at further cerebrovascular event or at the end of 5-year follow-up. When a patient had daily smoking, increased HbA1c, increased LDL-chol, increased systolic blood pressure, or increased diastolic blood pressure, the patient was categorized as showing atherosclerotic burden. Angiographic disease progression was determined using changes on magnetic resonance angiography.

RESULTS

Eleven patients showed angiographic disease progression and seven of these 11 patients experienced further cerebrovascular events during the follow-up period. The remaining 60 patients did not exhibit either condition. At inclusion, the incidence of atherosclerotic burden was significantly greater in patients without angiographic disease progression (80%) than in those with such progression (45%; p = 0.0249). For patients without angiographic disease progression, values or incidence of almost all variables showed significant interval decreases at the end of 5-year follow-up (p < 0.05).

CONCLUSIONS

Adult patients with ischemic MMD who do not exhibit angiographic disease progression appear more strongly affected by atherosclerotic burden at the initial onset of cerebrovascular events than those exhibiting angiographic disease progression. A reduction in atherosclerotic burden by medical treatments for the former patients prevents further cerebrovascular events.

Long-term study of the cognitive profile of Moyamoya Disease in adults

Moyamoya Disease (MMD) is a rare cerebrovascular disorder which can have significant cognitive consequences. The aim of the current study was to describe comprehensively the domain-specific cognitive profile of adult patients with MMD and to assess whether this changes in the absence of recurrent stroke over long-term follow-up. Comprehensive neuropsychological assessment covering seven cognitive domains was conducted on 61 adult patients with MMD at baseline and then at up to 3 further time points during follow up (median=2.31, 4.87 and 7.12 years). Although 27 patients had had prior surgical revasculariation, none had surgery between neuropsychological assessments. Cognitive impairment was common. At baseline, impairment in executive functions was most frequent (57%), followed by performance IQ (36%), speed of information processing (31%) and visual memory (30%). We found that the neuropsychological profile remains broadly stable over long-term follow-up with no clear indication of improvement or significant decline. The pattern of impairment also did not differ depending on age of onset or whether there was a history of either prior stroke at presentation or revascularisation surgery at presentation.

Risk Factors for Ischemic Stroke After Revascularization Surgery in Patients with Moyamoya Disease: An Age-Stratified Comparative Meta-Analysis

BACKGROUND

Patients who undergo revascularization surgery for moyamoya disease may develop postoperative ischemic stroke (pIS). Several studies have sought to identify risk factors; however, the findings remain highly inconsistent.

METHODS

PubMed, Scopus, and Web of Science were used to extract references. The first phase of screening required the studies to be in English, involve patients surgically treated for moyamoya disease, and report pIS. The second phase required the studies to provide ≥10 patients and include a control group.

RESULTS

All 22 studies were rated as high quality. Univariate analysis identified pediatrics <3 years of age as a risk factor for pIS (odds ratio [OR], 7.60; P < 0.0001). Among adult patients only, diabetes (OR, 2.10; P = 0.005), a Suzuki grade greater than 3 (OR, 1.74; P = 0.005), mean intraoperative systolic blood pressure (OR, 1.04; P < 0.0001), mean intraoperative diastolic blood pressure (OR, 1.04; P = 0.002), and revascularization in the left hemisphere (OR, 2.09; P = 0.001) were risk factors. Among both age groups, preoperative ischemic stroke (OR, 2.59; P < 0.00001) was a risk factor for pIS. Additionally, perioperative antiplatelet drug administration was a protective factor for specifically acute postoperative white thrombus among adult patients (OR, 0.35; P = 0.002).

CONCLUSIONS

In addition to the methods discussed that can mitigate the risk of pIS, the risk factors identified in our analysis may be of great value among surgeons for identifying high-risk patients in order to apply prophylactic measures, as well as scheduling longer and more frequent follow-up visits.

Effect of the addition of 123I-iomazenil single-photon emission computed tomography to brain perfusion single-photon emission computed tomography on the detection accuracy of misery perfusion in adult patients with ischemic moyamoya disease

OBJECTIVE

The present prospective study aimed to determine whether the addition of ¹²³I-iomazenil (IMZ) single-photon emission computed tomography (SPECT) to brain perfusion SPECT could improve the detection accuracy of misery perfusion on positron emission tomography (PET) in adult patients with ischemic moyamoya disease (MMD).

METHODS

Oxygen extraction fraction (OEF) and brain perfusion were assessed using ¹⁵O gas PET and N-isopropyl-p-[¹²³I]-iodoamphetamine (IMP) SPECT, respectively, in 137 patients. IMZ SPECT was also performed. Regions of interest (ROIs) were automatically placed in the five middle cerebral artery (MCA) territories ipsilateral to the symptomatic cerebral hemisphere and in the contralateral posterior cerebral artery territory using a three-dimensional stereotaxic ROI template. The radioactive count of the MCA ROI to the contralateral posterior cerebral artery ROI was calculated on IMP SPECT (relative SPECT-IMP uptake) and IMZ SPECT (relative SPECT-IMZ uptake). The relative SPECT-IMZ uptake to the relative SPECT-IMP uptake was also calculated (relative SPECT-IMZ/IMP uptake). Of the five MCA ROIs in the symptomatic cerebral hemisphere in each patient, the ROI with the highest PET-OEF value (one ROI per patient) was selected for analysis.

RESULTS

Significant correlations were observed between the PET-OEF and relative SPECT-IMP uptake (correlation coefficient, - 0.683) and relative SPECT-IMZ/IMP uptake (correlation coefficient, 0.875). The area under the receiver operating characteristic curve for detecting misery perfusion (PET-OEF > 51.3%) was significantly greater for the relative SPECT-IMZ/IMP uptake than for the relative SPECT-IMP uptake (difference between areas, 0.080; p = 0.0004). The sensitivity, specificity, and positive- and negative-predictive values for the relative SPECT-IMZ/IMP uptake for detecting misery perfusion were 100%, 92%, 81%, and 100%, respectively. The specificity and positive-predictive value were significantly greater for the relative SPECT-IMZ/IMP uptake than for the relative SPECT-IMP uptake.

CONCLUSIONS

The addition of IMZ SPECT to brain perfusion SPECT improves the detection accuracy of misery perfusion on PET in adult patients with ischemic MMD.

European Stroke Organisation (ESO) Guidelines on Moyamoya angiopathy: Endorsed by Vascular European Reference Network (VASCERN)

The European Stroke Organisation (ESO) guidelines on Moyamoya Angiopathy (MMA), developed according to ESO standard operating procedure and Grading of Recommendations, Assessment, Development and Evaluation (GRADE) methodology, were compiled to assist clinicians in managing patients with MMA in their decision making. A working group involving neurologists, neurosurgeons, a geneticist and methodologists identified nine relevant clinical questions, performed systematic literature reviews and, whenever possible, meta-analyses. Quality assessment of the available evidence was made with specific recommendations. In the absence of sufficient evidence to provide recommendations, Expert Consensus Statements were formulated. Based on low quality evidence from one RCT, we recommend direct bypass surgery in adult patients with haemorrhagic presentation. For ischaemic adult patients and children, we suggest revascularization surgery using direct or combined technique rather than indirect, in the presence of haemodynamic impairment and with an interval of 6–12 weeks between the last cerebrovascular event and surgery. In the absence of robust trial, an Expert Consensus was reached recommending long-term antiplatelet therapy in non-haemorrhagic MMA, as it may reduce risk of embolic stroke. We also agreed on the utility of performing pre- and post- operative haemodynamic and posterior cerebral artery assessment. There were insufficient data to recommend systematic variant screening of RNF213 p.R4810K. Additionally, we suggest that long-term MMA neuroimaging follow up may guide therapeutic decision making by assessing the disease progression. We believe that this guideline, which is the first comprehensive European guideline on MMA management using GRADE methods will assist clinicians to choose the most effective management strategy for MMA.

Preoperative Brain Functional Connectivity Improve Predictive Accuracy of Outcomes After Revascularization in Moyamoya Disease

BACKGROUND

In patients with moyamoya disease (MMD), focal impairments in cerebral hemodynamics are often inconsistent with patients' clinical prognoses. Evaluation of entire brain functional networks may enable predicting MMD outcomes after revascularization.

OBJECTIVE

To investigate whether preoperative brain functional connectivity could predict outcomes after revascularization in MMD.

METHODS

We included 34 patients with MMD who underwent preoperative MRI scanning and combined revascularization surgery. We used region of interest analyses to explore the differences in functional connectivity for 90 paired brain regions between patients who had favorable outcomes 1 year after surgery (no recurrent stroke, with improved preoperative symptoms, or modified Rankin Scale [mRS]) and those who had unimproved outcomes (recurrent stroke, persistent symptoms, or declined mRS). Variables, including age, body mass index, mRS at admission, Suzuki stage, posterior cerebral artery involvement, and functional connectivity with significant differences between the groups, were included in the discriminant function analysis to predict patient outcomes.

RESULTS

Functional connectivity between posterior cingulate cortex and paracentral lobule within the right hemisphere, and interhemispheric connection between superior parietal gyrus and middle frontal gyrus, precuneus and middle cingulate cortex, cuneus and precuneus, differed significantly between the groups (P < .001, false discovery rate corrected) and had the greatest discriminant function in the prediction model. Although clinical characteristics of patients with MMD showed great accuracy in predicting outcomes (64.7%), adding information on functional connections improved accuracy to 91.2%.

CONCLUSION

Preoperative functional connectivity derived from rs-fMRI may be an early hallmark for predicting patients' prognosis after revascularization surgery for MMD.

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.

Development of cerebral microbleeds and its impact on cognitive function in adult patients receiving medical management alone for ischemic moyamoya disease: supplementary analysis of a 5-year prospective cohort

OBJECTIVE

De novo cerebral microbleeds (CMBs) on T2*-weighted magnetic resonance imaging (MRI) develop over time in adult moyamoya disease (MMD) and are generally associated with a decline in global cognitive function. The present supplementary analysis of a 5-year prospective cohort aimed to elucidate the incidence of an interval increase in CMBs in adult patients receiving medical management alone for ischemic MMD and its impact on cognitive function.

METHODS

Sixty-four patients without misery perfusion in the symptomatic cerebral hemispheres at inclusion who did not experience any further ischemic symptoms or new hemorrhagic events during a 5-year follow-up period underwent T2*-weighted MRI and five kinds of neuropsychologic tests at inclusion and the end of the 5-year follow-up.

RESULTS

When T2*-weighted MRI was compared between inclusion and the end of the 5-year follow-up, 10 patients (15%) had an interval increase in CMBs in the symptomatic cerebral hemisphere at inclusion. The scores from two kinds of neuropsychologic tests significantly deteriorated at the end of the 5-year follow-up compared with those at inclusion in patients with an interval increase in CMBs, whereas the scores of four kinds of neuropsychologic tests significantly improved at the end of the 5-year follow-up compared with those at inclusion in patients without interval increases in CMBs, asymptomatic ischemic lesions, or angiographic disease progression.

CONCLUSIONS

The incidence of an interval increase in CMBs was 15% per 5 years in adult patients receiving medical management alone for ischemic MMD, and this increase was associated with a decline in cognitive decline.

Does Advanced Imaging Aid in the Preoperative Evaluation of Patients With Moyamoya Disease?

Background Moyamoya disease is characterized by progressive nonatherosclerotic stenosis and eventual occlusion of the supraclinoid cerebral arteries with the associated development of abnormal collateral vessels. Treatment of moyamoya disease revolves around restoring cerebral blood flow (CBF) distal to the steno-occlusive disease. Numerous modalities can be used to assess hemodynamic parameters. We sought to determine the impact of preoperative imaging on surgical decision-making. Methods A retrospective review was performed of all patients seen with the diagnosis of moyamoya. Patients were grouped on presentation based on CT/MRI findings of infarction, hemorrhage, or normal. Patients who did not have all of the preoperative tests were excluded. Preoperative radiological results were dichotomized as either normal or abnormal. Results During a five-year period, 34 patients with moyamoya met the inclusion criteria. All patients had an abnormal magnetic resonance angiography (MRA) Non-invasive Optimal Vessel Analysis (NOVA; VasSol, Inc, River Forest, IL). Three patients had normal initial MRI. All symptomatic patients had abnormal preoperative workup and underwent revascularization, as all were found to have abnormal single photon emission computed tomography (SPECT). The only occasion where the decision for surgery or type of surgery was influenced by imaging findings was in patients with nonclassical or minimal symptoms. Conclusion Although hemodynamic imaging studies can aid in establishing a preoperative baseline of CBF and cerebral vascular reserve (CVR) for follow-up studies, the true implication of these tests in the preoperative evaluation of clearly symptomatic moyamoya patients is debatable. In asymptomatic/mildly symptomatic patients, hemodynamic studies are necessary to determine the need for treatment. For symptomatic patients, surgery can be performed without an exhaustive and costly preoperative hemodynamic evaluation.

Outcomes of medical management alone for adult patients with cerebral misery perfusion due to ischemic moyamoya disease

OBJECTIVES

Although revascularization surgery is recommended for adult patients with moyamoya disease (MMD) who present with ischemic symptoms due to hemodynamic compromise, the clinical course of such patients who are treated with medical management alone remains unclear. Here, we report outcomes of adult patients with cerebral misery perfusion due to ischemic MMD who received medical management alone.

MATERIALS AND METHODS

We prospectively followed up patients who showed misery perfusion in the symptomatic cerebral hemisphere on ¹⁵O gas positron emission tomography (PET) and received strict medical management alone after refusing revascularization surgery.

RESULTS

Of 57 patients who showed symptomatic misery perfusion on ¹⁵O gas PET, three (5%) were included into the present study. Two of these patients suffered further ischemic events at 7 and 8 months after inclusion, after which, their modified Rankin disability scale scores deteriorated. In the remaining patient, fatal intracerebral hemorrhage developed at 10 months after inclusion.

CONCLUSIONS

These findings suggest that receiving medical management alone is associated with considerably poor outcomes for adult patients with cerebral misery perfusion due to ischemic MMD.

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.

Delayed development of cerebral atrophy after cerebral hyperperfusion following arterial bypass for adult patients with ischemic moyamoya disease: supplementary analysis of a 5-year prospective cohort

BACKGROUND

Adult patients with moyamoya disease (MMD) occasionally exhibit cerebral hyperperfusion after arterial bypass surgery, leading to persistent cognitive decline. The present supplementary analysis of a prospective 5-year cohort study aimed to determine whether cerebral hyperperfusion after arterial bypass surgery for adult patients with misery perfusion due to ischemic MMD causes cerebral atrophy, and whether the development of cerebral atrophy is related to persistent cognitive decline.

METHODS

In total, 31 patients who underwent arterial bypass surgery also underwent fluid-attenuated inversion recovery (FLAIR) magnetic resonance imaging (MRI) and neuropsychological testing before surgery and at the end of a 5-year follow-up. The development of cerebral hyperperfusion and hyperperfusion syndrome after surgery was defined based on brain perfusion single-photon emission computed tomography (SPECT) findings and clinical symptoms. Univariate and multivariate logistic regression analyses of factors related to the development of cerebral atrophy on FLAIR MRI or cognitive decline on neuropsychological testing at the end of the 5-year follow-up were performed.

RESULTS

Eleven patients (35%) developed cerebral atrophy in the frontal lobe where the superficial temporal artery was anastomosed. Cerebral hyperperfusion on brain perfusion SPECT (odds ratio [OR], 50.6; p = 0.0008) or cerebral hyperperfusion syndrome (OR, 41.8; p = 0.0026) was independently associated with the development of cerebral atrophy, and cerebral atrophy development was significantly associated with cognitive decline (OR, 47.7; p = 0.0010).

CONCLUSIONS

Cerebral hyperperfusion after arterial bypass surgery for adult patients with misery perfusion due to ischemic MMD can cause cerebral atrophy related to persistent cognitive decline.

Daily Remote Ischemic Conditioning Can Improve Cerebral Perfusion and Slow Arterial Progression of Adult Moyamoya Disease—A Randomized Controlled Study

Background and Purpose

Moyamoya disease (MMD) is a complicated cerebrovascular disease with recurrent ischemic or hemorrhagic events. This study aimed to prove the safety and efficacy of remote ischemic conditioning (RIC) on MMD.

Methods

In total, 34 patients with MMD participated in this pilot, prospective randomized controlled study for 1 year. 18 patients were allocated into the RIC group, and 16 patients accepted routine medical treatment only. RIC-related adverse events were recorded. The primary outcome was the improvement ratio of mean cerebral blood flow (mCBF) in middle cerebral artery territory measured by multidelay pseudocontinuous arterial spin labeling, and the secondary outcomes were the cumulative incidence of major adverse cerebrovascular events (MACEs), the prevalence of stenotic-occlusive progression, and periventricular anastomosis at 1-year follow-up.

Results

In total, 30 of the 34 patients with MMD completed the final follow-up (17 in the RIC group and 13 in the control group). No adverse events of RIC were observed. The mCBF improvement ratio of the RIC group was distinctively higher compared with the control group (mCBF−whole-brain: 0.16 ± 0.15 vs. −0.03 ± 0.13, p = 0.001). Stenotic-occlusive progression occurred in 11.8% hemispheres in the RIC group and 38.5% in the control group (p = 0.021). The incidence of MACE was 5.9% in the RIC group and 30.8% in the control group (hazard ratio with RIC, 0.174; 95% CI, 0.019–1.557; p = 0.118). No statistical difference was documented in the periventricular anastomosis between the two groups after treatment.

Conclusions

Remote ischemic conditioning has the potential to be a safe and effective adjunctive therapy for patients with MMD largely due to improving cerebral blood flow and slowing the arterial progression of the stenotic-occlusive lesions. These findings warrant future studies in larger trials.

Macrohistory of Moyamoya Disease Analyzed Using Artificial Intelligence

INTRODUCTION

Moyamoya disease is characterized by progressive stenotic changes in the terminal segment of the internal carotid artery and the development of abnormal vascular networks called moyamoya vessels. The objective of this review was to provide a holistic view of the epidemiology, etiology, clinical findings, treatment, and pathogenesis of moyamoya disease. A literature search was performed in PubMed using the term "moyamoya disease," for articles published until 2021.

RESULTS

Artificial intelligence (AI) clustering was used to classify the articles into 5 clusters: (1) pathophysiology (23.5%); (2) clinical background (37.3%); (3) imaging (13.2%); (4) treatment (17.3%); and (5) genetics (8.7%). Many articles in the "clinical background" cluster were published from the 1970s. However, in the "treatment" and "genetics" clusters, the articles were published from the 2010s through 2021. In 2011, it was confirmed that a gene called Ringin protein 213 (RNF213) is a susceptibility gene for moyamoya disease. Since then, tremendous progress in genomic, transcriptomic, and epigenetic profiling (e.g., methylation profiling) has resulted in new concepts for classifying moyamoya disease. Our literature survey revealed that the pathogenesis involves aberrations of multiple signaling pathways through genetic mutations and altered gene expression.

CONCLUSION

We analyzed the content vectors in abstracts using AI, and reviewed the pathophysiology, clinical background, radiological features, treatments, and genetic peculiarity of moyamoya disease.

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

OBJECTIVES

Adult patients with moyamoya disease (MMD) occasionally develop cognitive decline due to cerebral hyperperfusion following direct revascularization surgery. However, how the hyperperfusion phenomenon contributes to declines in cognitive function remains unclear. The present supplementary analysis of a prospective study aimed to determine whether cerebral hyperperfusion following direct revascularization surgery for adult MMD with ischemic presentation and misery perfusion leads to development of de novo cerebral microbleeds (CMBs) and whether postoperative cognitive decline is related to these CMBs.

MATERIALS AND METHODS

In total, 32 patients who underwent direct revascularization surgery also underwent T2*-weighted magnetic resonance imaging (T2*WI) and neuropsychological testing before and 2 months after surgery. Development of cerebral hyperperfusion and hyperperfusion syndrome following surgery was defined based on brain perfusion single-photon emission computed tomography (SPECT) findings and clinical symptoms.

RESULTS

Cerebral hyperperfusion on brain perfusion SPECT (95% confidence interval [CI], 1.1-10.8; p = 0.0175) or cerebral hyperperfusion syndrome (95%CI, 1.3-15.3; p = 0.0029) was significantly associated with postoperatively increased CMBs on T2*WI. Postoperatively increased CMBs were significantly associated with postoperative cognitive decline (95%CI, 1.8-20.4, p = 0.0041). For patients with cerebral hyperperfusion on brain perfusion SPECT, the incidence of postoperative cognitive decline was significantly greater in patients with than in those without postoperatively increased CMBs (p = 0.0294).

CONCLUSIONS

Cerebral hyperperfusion following direct revascularization surgery for adult MMD with ischemic presentation and misery perfusion contributes to the development of de novo CMBs and postoperative cognitive decline is related to these CMBs.

Angiographic disease progression in medically treated adult patients with ischemic moyamoya disease without cerebral misery perfusion: supplementary analysis of a 5-year prospective cohort

Angiographic disease progression reportedly develops in adult moyamoya disease (MMD). However, more than half of patients analyzed underwent revascularization surgery. The present supplementary analysis of a 5-year prospective cohort with follow-up using magnetic resonance angiography (MRA) and cerebral blood flow (CBF) measurements was to elucidate the incidence and clinical features of angiographic disease progression in adult patients receiving medical management alone for ischemic MMD. Sixty-eight patients without misery perfusion in the symptomatic cerebral hemispheres underwent MRA and CBF measurement using brain perfusion single-photon emission computed tomography at inclusion and at the end of the 5-year follow-up. When neurological symptoms recurred or newly developed during the 5-year follow-up period, additional MRA and CBF measurements were also performed at that time. All four patients with further ischemic events during the 5-year follow-up period exhibited angiographic disease progression on MRA at such events. Of the remaining 64 patients without further events during the 5-year follow-up period, four exhibited angiographic disease progression on MRA at the end of the 5-year follow-up. CBF was significantly lower at the time of further ischemic events or at the end of the 5-year follow-up than at inclusion in eight patients with angiographic disease progression (p = 0.0117). The incidence of angiographic disease progression was 12% for 5 years in medically treated adult patients with ischemic MMD without cerebral misery perfusion. Patients with further ischemic events always exhibited angiographic disease progression. Cerebral perfusion was reduced in patients with angiographic disease progression even when further ischemic events did not occur.

Clinical Management of Moyamoya Patients

Moyamoya angiopathy (MMA) is a peculiar cerebrovascular condition characterized by progressive steno-occlusion of the terminal part of the internal carotid arteries (ICAs) and their proximal branches, associated with the development of a network of fragile collateral vessels at the base of the brain. The diagnosis is essentially made by radiological angiographic techniques. MMA is often idiopathic (moyamoya disease-MMD); conversely, it can be associated with acquired or hereditary conditions (moyamoya Syndrome-MMS); however, the pathophysiology underlying either MMD or MMS has not been fully elucidated to date, and this poor knowledge reflects uncertainties and heterogeneity in patient management. MMD and MMS also have similar clinical expressions, including, above all, ischemic and hemorrhagic strokes, then headaches, seizures, cognitive impairment, and movement disorders. The available treatment strategies are currently shared between idiopathic MMD and MMS, including pharmacological and surgical stroke prevention treatments and symptomatic drugs. No pharmacological treatment able to reverse the progressive disappearance of the ICAs has been found to date in both idiopathic and syndromic cases. Antithrombotic agents are usually prescribed in ischemic MMA, although the coexisting hemorrhagic risk should be considered. Surgical revascularization techniques, which are currently the best available treatment in symptomatic MMA, are associated with good long-term outcomes and reduced ischemic and hemorrhagic risks. Given the lack of dedicated randomized clinical trials, current treatment is mainly based on observational studies and physicians’ and surgeons’ expertise.

RNF213 and GUCY1A3 in Moyamoya Disease: Key Regulators of Metabolism, Inflammation, and Vascular Stability

Moyamoya disease is an idiopathic chronically progressive cerebrovascular disease, which causes both ischemic and hemorrhagic stroke. Genetic studies identified RNF213/Mysterin and GUCY1A3 as disease-causing genes. They were also known to be associated with non-moyamoya intracranial large artery disease, coronary artery disease and pulmonary artery hypertension. This review focused on these two molecules and their strong linker, calcineurin/NFAT signaling and caveolin to understand the pathophysiology of moyamoya disease and related vascular diseases. They are important regulators of lipid metabolism especially lipotoxicity, NF-κB mediated inflammation, and nitric oxide-mediated vascular protection. Although intimal thickening with fibrosis and damaged vascular smooth muscle cells are the distinguishing features of moyamoya disease, origin of the fibrous tissue and the mechanism of smooth muscle cell damages remains not fully elucidated. Endothelial cells and smooth muscle cells have long been a focus of interest, but other vascular components such as immune cells and extracellular matrix also need to be investigated in future studies. Molecular research on moyamoya disease would give us a clue to understand the mechanism preserving vascular stability.

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.

Diagnostic Accuracy of Screening Arterial Spin-Labeling MRI Using Hadamard Encoding for the Detection of Reduced CBF in Adult Patients with Ischemic Moyamoya Disease

BACKGROUND AND PURPOSE

Adult patients with ischemic Moyamoya disease are advised to undergo selective revascularization surgery based on cerebral hemodynamics. The purpose of this study was to determine the diagnostic accuracy of arterial spin-labeling MR imaging using Hadamard-encoded multiple postlabeling delays for the detection of reduced CBF in such patients.

MATERIALS AND METHODS

Thirty-seven patients underwent brain perfusion SPECT and pseudocontinuous arterial spin-labeling MR imaging using standard postlabeling delay (1525 ms) and Hadamard-encoded multiple postlabeling delays. For Hadamard-encoded multiple postlabeling delays, based on data obtained from the 7 sub-boluses with combinations of different labeling durations and postlabeling delays, CBF corrected by the arterial transit time was calculated on a voxel-by-voxel basis. Using a 3D stereotaxic template, we automatically placed ROIs in the ipsilateral cerebellar hemisphere and 5 MCA territories in the symptomatic cerebral hemisphere; then, the ratio of the MCA to cerebellar ROI was calculated.

RESULTS

The area under the receiver operating characteristic curve for detecting reduced SPECT-CBF ratios (<0.686) was significantly greater for the Hadamard-encoded multiple postlabeling delays-CBF ratios (0.885) than for the standard postlabeling delay-CBF ratios (0.786) (P = .001). The sensitivity and negative predictive value for the Hadamard-encoded multiple postlabeling delays-CBF ratios were 100% (95% confidence interval, 100%-100%) and significantly higher than the sensitivity (95% CI, 44%-80%) and negative predictive value (95% CI, 88%-97%) for the standard postlabeling delay-CBF ratio, respectively.

CONCLUSIONS

ASL MR imaging using Hadamard-encoded multiple postlabeling delays may be applicable as a screening tool because it can detect reduced CBF on brain perfusion SPECT with 100% sensitivity and a 100% negative predictive value in adult patients with ischemic Moyamoya disease.

Effects of aspirin and heparin treatment on perioperative outcomes in patients with Moyamoya disease

BACKGROUND

When superficial temporal artery-middle cerebral artery bypass is combined with indirect methods (e.g., revascularization surgery) to treat Moyamoya disease (MMD), antiplatelet treatment can impact bypass patency, infarction, or hemorrhage complications. Recently, heparin has been proposed as an anticoagulant treatment against white thrombus at the anastomosis site. The study aims to evaluate the effect of aspirin on the perioperative outcomes and investigate the results of heparin treatment for white thrombus.

METHODS

This retrospective study included 74 procedures of combined revascularization surgery for MMD patients who either received or did not receive aspirin. Perioperative outcomes were compared between the two groups. In addition, the effects of heparin treatment for white thrombus were evaluated.

RESULTS

The rate of white thrombus at the anastomosis site was significantly higher in the non-aspirin medication group (univariate: p = 0.032, multivariate: p = 0.044) and, accordingly, initial bypass patency was lower in the non-aspirin medication group (p = 0.049). Of the 17 patients with white thrombus development, five received heparin injections, and all white thrombi disappeared; however, there was one case of epidural hematoma and another of subdural hematoma. The risk of hemorrhagic complications was significantly higher in the surgical procedures that received heparin injections (p = 0.021).

CONCLUSIONS

In MMD patients who received combined revascularization surgery, aspirin medication lowered the occurrence of white thrombus. Heparin injections help to treat white thrombus but can enhance the risk of hemorrhagic complications.

Efficacy and Safety of Antiplatelet Agents for Adult Patients With Ischemic Moyamoya Disease

Background: The use of antiplatelet agents in ischemic moyamoya disease (MMD) is controversial. This study aimed to investigate the effectiveness and safety of antiplatelet therapy compared with conservative treatment and surgical revascularization in ischemic MMD patients. Methods: Ischemic MMD patients were retrospectively enrolled from eight clinical sites from January 2013 to December 2018. Follow-up was performed through clinical visits and/or telephone interviews from first discharge to December 2019. The primary outcome was the episodes of further ischemic attacks, and the secondary outcome was the individual functional status. Risk factors for future stroke were identified by the LASSO-Cox regression model. Propensity score matching was applied to assemble a cohort of patients with similar baseline characteristics using the TriMatch package. Results: Among 217 eligible patients, 159 patients were included in the analyses after a 1:1:1 propensity score matching. At a mean follow-up of 33 months, 12 patients (7.5%) developed further incident cerebral ischemic events (surgical:antiplatelet:conservative = 1:3:8; p = 0.030), 26 patients (16.4%) developed a poor functional status (surgical:antiplatelet:conservative = 7:12:7; p = 0.317), and 3 patients (1.8%) died of cerebral hemorrhage (surgical:antiplatelet:conservative = 1:2:0; p = 0.361). The survival curve showed that the risk of further cerebral ischemic attacks was lowest with surgical revascularization, while antiplatelet therapy was statistically significant for preventing recurrent risks compared with conservative treatment (χ² = 8.987; p = 0.011). No significant difference was found in the functional status and bleeding events. The LASSO-Cox regression model revealed that a family history of MMD (HR = 6.93; 95% CI: 1.28-37.52; p = 0.025), a past history of stroke or transient ischemic attack (HR = 4.35; 95% CI: 1.09-17.33; p = 0.037), and treatment (HR = 0.05; 95% CI: 0.01-0.32; p = 0.001) were significantly related to the risk of recurrent strokes. Conclusions: Antiplatelet agents were effective and safe in preventing further cerebral ischemic attacks in adult patients with ischemic MMD. They may be a replacement therapy for patients with surgical contraindications and for patients prior to revascularization.

Basal and Acetazolamide Brain Perfusion SPECT in Internal Carotid Artery Stenosis

Internal carotid artery (ICA) stenosis including Moyamoya disease needs revascularization when hemodynamic insufficiency is validated. Vascular reserve impairment was the key to find the indication for endarterectomy/bypass surgery in the atherosclerotic ICA stenosis and to determine the indication, treatment effect, and prognosis in Moyamoya diseases. Vascular reserve was quantitatively assessed by 1-day split-dose I-123 IMP basal/acetazolamide SPECT in Japan or by Tc-99m HMPAO SPECT in other countries using qualitative or semi-quantitative method. We summarized the development of 1-day basal/ acetazolamide brain perfusion SPECT for ICA stenosis, both quantitative and qualitative methods, and their methodological issues regarding (1) acquisition protocol; (2) qualitative assessment, either visual or deep learning-based; (3) clinical use for atherosclerotic ICA steno-occlusive diseases and mostly Moyamoya diseases; and (4) their impact on the choice of treatment options. Trials to use CT perfusion or perfusion MRI using contrast materials or arterial spin labeling were briefly discussed in their endeavor to use basal studies alone to replace acetazolamide-challenge SPECT. Theoretical and practical issues imply that basal perfusion evaluation, no matter how much sophisticated, will not disclose vascular reserve. Acetazolamide rarely causes serious adverse reactions but included fatality, and now, we need to monitor patients closely in acetazolamide-challenge studies.

Predictors of clinical or cerebral lesion progression in adult moyamoya angiopathy

OBJECTIVE

To identify independent predictors of clinical or cerebral lesion progression in a large sample of adult patients with moyamoya angiopathy (MMA) prior to decisions regarding revascularization surgery.

METHODS

Ninety participants (median age, 37.5 years) were assessed at baseline and followed for a median time of 42.8 months. Incident ischemic and hemorrhagic strokes, death, as well as any incident ischemic and hemorrhagic lesions on MRI were recorded. Multiple demographic, clinical, and cerebral imaging measures at baseline were considered as potential predictors of clinical or cerebral tissue change at follow-up. Data were analyzed based on the Andersen-Gill counting process model, followed by internal validation of the prediction model.

RESULTS

Among multiple potential predictive measures considered in the analysis, Asian origin, a history of TIAs, and a reduction in hemodynamic reserve, as detected by imaging, were found to be significantly associated with an increased risk of combined clinical and imaging events. While the model estimated the risk of clinical or cerebral lesion progression to be approximately 0.5% per year when none of these factors was present, this risk exceeded 20% per year when all factors were present.

CONCLUSION

A simple combination of demographic, clinical, and cerebral perfusion imaging measures may aid in predicting the risk of incident stroke and cerebral lesion progression in adult patients with MMA. These results may help to improve therapeutic decisions and aid in the design of future trials in adults with this rare condition.

Brain Structure, Connectivity, and Cognitive Changes Following Revascularization Surgery in Adult Moyamoya Disease

BACKGROUND

The effect of the combined direct/indirect revascularization surgery in Moyamoya disease has not been evaluated sufficiently with regard to cognitive function, brain microstructure, and connectivity.

OBJECTIVE

To investigate structural and functional changes following revascularization surgery in patients with moyamoya disease (MMD) through a combined analysis of brain morphology, microstructure, connectivity, and neurobehavioral data.

METHODS

Neurobehavioral and neuroimaging examinations were performed in 25 adults with MMD prior to and >12 mo after revascularization surgery. Cognitive function was investigated using the Wechsler Adult Intelligence Scale-III, Trail-Making Test, Wisconsin Card Sorting Test, Continuous Performance Test, Stroop test, and Wechsler Memory Scale. We assessed white matter integrity using diffusion tensor imaging, brain morphometry using magnetization-prepared rapid gradient-echo sequences, and brain connectivity using resting-state functional magnetic resonance imaging (MRI).

RESULTS

Cognitive examinations revealed significant changes in the full-scale intelligence quotient (IQ), performance IQ (PIQ), perceptual organization (PO), processing speed, and Stroop test scores after surgery (P < .05). Enlargement of the lateral ventricle, volume reductions in the corpus callosum and subcortical nuclei, and cortical thinning in the prefrontal cortex were also observed (P < .05). Fractional anisotropy in the white matter tracts, including the superior longitudinal fasciculus, increased 2 to 4 yr after surgery, relative to that observed in the presurgical state (P < .05). Resting-state brain connectivity was increased predominantly in the fronto-cerebellar circuit and was positively correlated with improvements in PIQ and PO (P < .05).

CONCLUSION

Revascularization surgery may improve processing speed and attention in adult patients with MMD. Further, multimodal MRI may be useful for detecting subtle postsurgical brain structural changes, reorganization of white matter tracts, and brain connectivity alterations.

Comparison of Effects between Clopidogrel and Cilostazol on Cerebral Perfusion in Nonsurgical Adult Patients with Symptomatically Ischemic Moyamoya Disease: Subanalysis of a Prospective Cohort

BACKGROUND AND PURPOSE

Adult patients with symptomatically ischemic moyamoya disease (MMD) initially undergo medical treatment alone including antiplatelet drugs when symptomatic cerebral hemispheres do not exhibit hemodynamic compromise. The purpose of the present study subanalyzing the same patient cohort used in a previous study was to determine which antiplatelet drug, clopidogrel or cilostazol, provides better improvement of cerebral perfusion in such patients.

METHODS

All patients without cerebral misery perfusion on ¹⁵O gas positron emission tomography (PET) did not undergo revascularization surgery and were treated with medication alone, including antiplatelet therapy. Patients ≥50years and <50years initially received clopidogrel and cilostazol, respectively. When a patient suffered side effects of an antiplatelet drug, they were switched to the other antiplatelet drug. Cerebral blood flow (CBF) in the symptomatic hemisphere was measured at inclusion and at 2years after inclusion using ¹⁵O gas PET.

RESULTS

Of 68 patients, 31 and 38 were treated with clopidogrel and cilostazol, respectively, for 2years after inclusion. For patients treated with clopidogrel, CBF did not differ between first and second PET. For patients treated with cilostazol, CBF was significantly greater in the second PET than in the first PET. On multivariate analysis, cilostazol administration was an independent predictor of CBF improvement in the symptomatic hemisphere (95% confidence interval, 1.34-139.20; P =.0271).

CONCLUSIONS

Cilostazol improves cerebral perfusion better than clopidogrel in adult patients with symptomatically ischemic MMD not accompanied by misery perfusion.

Accuracy of brain perfusion single-photon emission computed tomography for detecting misery perfusion in adult patients with symptomatic ischemic moyamoya disease

OBJECTIVE

The purpose of the present study was to determine how accurately relative cerebral blood flow (RCBF) and relative cerebrovascular reactivity (RCVR) to acetazolamide assessed using brain perfusion single-photon emission computed tomography (SPECT) detected misery perfusion identified on positron emission tomography (PET) in adult patients with ischemic moyamoya disease (MMD).

METHODS

Oxygen extraction fraction (OEF), RCBF, and RCVR were assessed using ¹⁵O gas PET and N-isopropyl-p-[¹²³I]-iodoamphetamine SPECT without and with acetazolamide challenge, respectively, in 45 patients. Regions of interest (ROIs) were automatically placed in the five middle cerebral artery (MCA) territories in the symptomatic cerebral hemisphere and in the ipsilateral cerebellar hemisphere using a three-dimensional stereotaxic ROI template. For RCBF and RCVR to acetazolamide, the ratio of the MCA ROI to cerebellar ROI was calculated. Of the five MCA ROIs in the symptomatic cerebral hemisphere in each patient, the ROI with the highest and lowest OEF value (two ROIs per patient) was selected for analyses.

RESULTS

A significant square or linear correlation was observed between the OEF and RCBF (correlation coefficient, 0.780) or RCVR (correlation coefficient, - 0.345), respectively. The area under the receiver operating characteristic curve for detecting misery perfusion (OEF > 51.3%) was significantly greater for the RCBF than for the RCVR (difference between areas, 0.221; p < 0.0001). Sensitivity, specificity, and positive- and negative-predictive values for the RCBF for detecting misery perfusion were 100, 91, 67, and 100%, respectively. The specificity and positive-predictive value did not differ between the combination of the RCBF and RCVR and the CBF ratio alone.

CONCLUSIONS

RCBF assessed using brain perfusion SPECT detects misery perfusion with high sensitivity, a high negative-predictive value, and a low positive-predictive value in adult patients with ischemic MMD. The accuracy of RCVR to acetazolamide assessed using brain perfusion SPECT is lower than that of RCBF.