Risk Factors for Specific Postoperative Ischemic Complications in Patients with Moyamoya Disease: A Single-Center Retrospective Study.

AIM: To evaluate and compare postoperative ischemic complications to determine the risk factors for ischemic complications following revascularization surgery for Moyamoya disease (MMD). MATERIAL AND METHODS: This single-center retrospective study included 266 procedures between 2016 and 2021. Three types of revascularization approaches including direct bypass, indirect bypass, and combined bypass were performed. To identify risk factors for postoperative ischemic complications and contralateral cerebral infarction, preoperative clinical characteristics and radiographic features were examined using multivariate and ordinal logistic regression analyses. RESULTS: Postoperative ischemic complications occurred in 103 (6.6%) procedures. Ischemic presentation (p=0.001, odds ratios [OR] 5.59, 95% confidence interval [CI] 2.05-15.23), hypertension (p=0.030, OR 2.75, 95%CI 1.11- 6.83), advanced Suzuki stage (p=0.006, OR 3.19, 95%CI 1.40-7.26), and collateral circulation (p=0.001 OR 0.17, 95%CI 0.06-0.47) were risk factors for postoperative ischemic complications. Ordinal regression analysis revealed that unilateral involvement (p=0.043, OR 2.70, 95%CI 0.09-5.31), hemorrhagic presentation (p=0.013, OR 3.45, 95%CI 0.72-6.18), surgical approach (p=0.032, OR -1.38, 95%CI -2.65, -0.12), and collateral circulation [p=0.043, OR -1 .27, 95%CI -2.51, -0.04)] were associated with the type of ischemic complications. History of hypertension (p=0.031) and contralateral computed tomography (CT) perfusion stage (p=0.045) were associated with contralateral infarction. CONCLUSION: Inability of cerebral vessels to withstand changes in blood pressure induced by revascularization-related hemodynamic instability might be associated with postoperative complications in patients with Moyamoya disease.

Nonalcoholic fatty liver disease is an independent risk factor for ischemic stroke after revascularization in patients with Moyamoya disease: a prospective cohort study.

BACKGROUND: The study aimed to investigate the association between nonalcoholic fatty liver disease (NAFLD) and ischemic stroke events after revascularization in patients with Moyamoya disease (MMD). METHODS: This study prospectively enrolled 275 MMD patients from September 2020 to December 2021. Patients with alcoholism and other liver diseases were excluded. NAFLD was confirmed by CT imaging or abdominal ultrasonography. Stroke events and modified Rankin Scale (mRS) scores at the latest follow-up were compared between the two groups. RESULTS: A total of 275 patients were enrolled in the study, among which 65 were diagnosed with NAFLD. Univariate logistic regression analysis showed that NAFLD (P = 0.029) was related to stroke events. Multivariate logistic regression analysis showed that NAFLD is a predictor of postoperative stroke in MMD patients (OR = 27.145, 95% CI = 2.031-362.81, P = 0.013). Kaplan-Meier analysis showed that compared with MMD patients with NAFLD, patients in the control group had a longer stroke-free time (P = 0.004). Univariate Cox analysis showed that NAFLD (P = 0.016) was associated with ischemic stroke during follow-up in patients with MMD. Multivariate Cox analysis showed that NAFLD was an independent risk factor for stroke in patients with MMD (HR = 10.815, 95% CI = 1.259-92.881, P = 0.030). Furthermore, fewer patients in the NAFLD group had good neurologic status (mRS score ≤ 2) than the control group (P = 0.005). CONCLUSION: NAFLD was an independent risk factor for stroke in patients with MMD after revascularization and worse neurological function outcomes.

[Various Bypass Surgery:Preoperative Simulation for STA-MCA Bypass].

In STA-MCA bypass surgery, it is important to select the optimal recipient using preoperative simulation to avoid complications. We report a preoperative simulation for STA-MCA bypass using the Brain LAB iPLAN platform®BRAIN LAB)and the 3DCG simulation software GRID®Kompath). Here, we introduce the basics and applications of preoperative simulation for occlusive atherosclerotic lesions and present a target bypass for periventricular anastomosis and peripheral vessels of aneurysms in Moyamoya disease. By creating and visualizing 3D fusion images, the optimal donor and recipient can be selected. Determining the skin incision and extent of craniotomy according to the case is also applicable to the minimally invasive STA-MCA bypass. Preoperative simulations enable accurate pinpoint bypass surgery and prevent complications.

Persistent trigeminal artery in a patient with moyamoya disease:a case report and literature review.

BACKGROUNDS: Persistent trigeminal artery (PTA) is a rare anastomosis between internal carotid artery (ICA) and basilar artery. In rare conditions, the PTA could be combined with others cerebrovascular anomalies, moyamoya disease (MMD) is one of them. CASE PRESENTATION: Here, we reported one rare case of MMD associated with PTA, the patient admitted to our department for severe dizziness and headache, imaging examination suggested MMD combined with right PTA, which arising from the ipsilateral cavernous portion of ICA. The patient received phased bilaterral revascularization with no any complication. In the subsequent follow-up, the patient's symptoms and intracranial vascular condition gradually improved. Moreover, we conducted a literature review of coexistence of PTA and MMD, the results of a web of science regarding such condition, and a deep discussion providing brief insight into the status of co-occurrence of PTA and MMD, including its manifestation, treatment and outcome. CONCLUSIONS: The coexistence of PTA and MMD was rarely reported, the pathogenesis of such condition remains unknown. We found that the features of the coexistence of PTA and MMD were diverse, revascularization might be a feasible for such patient.

Risk Factors for Massive Cerebral Infarction in Pediatric Patients With Moyamoya Disease.

BACKGROUND: To explore the risk factors for preoperative massive cerebral infarction (MCI) in pediatric patients with moyamoya disease (MMD). METHODS: Pediatric patients with MMD treated between 2017 and 2022 were enrolled. Logistic regression analysis was performed to identify risk factors for MCI among the patients, and a nomogram was constructed to identify potential predictors of MCI. Receiver operating characteristic (ROC) curves and areas under the curves were calculated to determine the effects of different risk factors. RESULTS: This study included 308 pediatric patients with MMD, including 36 with MCI. The MCI group exhibited an earlier age of onset than the non-MCI group. Significant intergroup differences were observed in familial MMD history, postcirculation involvement, duration from diagnosis to initiation of treatment, Suzuki stage, magnetic resonance angiography (MRA) score, collateral circulation score, and RNF213 p.R4810K variations. Family history, higher MRA score, lower collateral circulation score, and RNF213 p.R4810K variations were substantial risk factors for MCI in pediatric patients with MMD. The nomogram demonstrated excellent discrimination and calibration capabilities. The integrated ROC model, which included all the abovementioned four variables, showed superior diagnostic precision with a sensitivity of 67.86%, specificity of 87.01%, and accuracy of 85.11%. CONCLUSIONS: This study showed that family history, elevated MRA score, reduced collateral circulation score, and RNF213 p.R4810K variations are risk factors for MCI in pediatric patients with MMD. The synthesized model including these variables demonstrated superior predictive efficacy; thus, it can facilitate early identification of at-risk patients and timely initiation of appropriate interventions.

Comparison between moyamoya disease and moyamoya syndrome in Israel.

BACKGROUND AND AIMS: Moyamoya is a chronic brain vasculopathy involving the distal intracranial internal carotid artery (ICA) or proximal middle cerebral artery (MCA). Moyamoya patients can be divided into those with primary moyamoya disease (MMD) and those with moyamoya secondary to other known causes such as intracranial atherosclerosis (moymoya syndrome [MMS]). Our aim was to compare the characteristics of MMD patients to those of MMS patients in a sample of Israeli patients seen over the course of 20 years at a tertiary referral center. METHODS: Included patients were diagnosed with either MMD or MMS based on typical imaging findings and the presence or absence of known concomitant vascular risk factors or associated disorders and vascular disease. Patients with MMS were compared to those with MMD. Demographics, symptoms, signs, and radiological data were compared between the groups. Treatment options and long-term rates of recurrent stroke and functional outcome were also studied. RESULTS: Overall, 64 patients were included (25 MMD, 39 MMS). Patients with MMD were significantly younger (median IQR 20 (7-32) vs. 40 (19-52); p=0.035). Patients with MMS more often had vascular risk factors but there were no significant differences in clinical presentations or long-term disability rates between the groups and a similar proportion of patients underwent surgical interventions to restore hemispheric perfusion in both groups (48% vs. 44% MMS vs. MMD; p=0.7). Almost one in four patient had a recurrent stroke after the initial diagnosis in both groups. Most recurrences occurred in the pre-surgery period in the MMS group and in the post-surgery period in the MMD group. CONCLUSIONS: There were no statistically significant differences in clinical or radiological presentations between the MMS and MMD patients. The course is not benign with recurrent stroke occurring in as many as 25%. More data is needed in order to identify those at high risk for stroke occurrence and recurrence.

Coexistence of moyamoya syndrome with arteriovenous malformation. Systematic review and illustrative case report.

The coexistence of Moyamoya Syndrome with Arteriovenous Malformation is exceedingly rare. Here, we present the case of a 37-year-old female patient diagnosed with AVM in the right parietal lobe, accompanied by severe stenosis of the right middle cerebral artery and right anterior cerebral artery, along with moyamoya collateral induction. Our objective was to investigate the frequency and mutual influence of these conditions, and to determine a preferable treatment strategy by conducting a comprehensive review of previous case reports. We conducted a thorough search of PubMed, Scopus, and Web of Science databases, adhering to Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Our review encompassed 36 publications, reporting a total of 64 cases of AVM coexisting with Moyamoya Syndrome. Notably, bilateral stenosis was observed in half of the cases. Among patients with unilateral stenosis, AVM was localized in the opposite hemisphere only in 2 cases. Treatment approaches varied, with 18 cases undergoing active treatment for both stenosis and AVM, 11 cases treating stenosis prior to AVM, 5 cases addressing AVM first, and 3 cases treating both AVM and stenosis simultaneously. Embolization, either standalone or supplemented by stereotactic radiosurgery, was employed in six cases. Stereotactic radiosurgery alone was utilized in 12 cases, while 15 patients underwent surgical removal of the AVM. Our findings provide valuable insights for neurosurgeons managing patients with concurrent AVM and Moyamoya Syndrome. The variety of treatment approaches observed in the literature underscores the complexity of these cases, emphasizing the need for individualized strategies. This information may guide future systematic reviews and meta-analyses, contributing to a better understanding of the optimal management of these rare coexisting vascular pathologies.

Pathological changes in the lenticulostriate artery indicate the mechanisms leading to intracranial hemorrhage in Moyamoya disease: a case report.

This case report details the pathological findings of a vessel wall identified as the bleeding point for intracranial hemorrhage associated with Moyamoya disease. A 29-year-old woman experienced intracranial hemorrhage unrelated to hyperperfusion following superficial temporal artery-middle cerebral artery bypass surgery. A pseudoaneurysm on the lenticulostriate artery (LSA) was identified as the causative vessel and subsequently excised. Examination of the excised pseudoaneurysm revealed a fragment of the LSA, with a disrupted internal elastic lamina and media degeneration. These pathological findings in a perforating artery, akin to the circle of Willis, provide insights into the underlying mechanisms of hemorrhage in Moyamoya disease.

Long-term Outcomes of Combined Revascularization Surgery for Moyamoya Disease in the Elderly: A Single Institute Experience.

The opportunity to treat older patients with Moyamoya disease (MMD) is increasing. However, the surgical outcomes after combined direct and indirect revascularization for elderly patients with MMD are not fully understood, especially for those ≥60 years old. This retrospective study examined 232 consecutive hemispheres of 165 adults with MMD who underwent combined revascularization. Clinical features and surgical outcomes were compared between the elderly (≥60 years) and nonelderly group (<60 years). Thirteen (5.6%, 64.4 ± 4.0 years old) and 219 hemispheres (94.4%, 40.2 ± 10.8 years old) were included in the elderly and nonelderly group, respectively. The proportion of clinical presentations before surgery did not differ. However, the prevalence of hypertension and hyperlipidemia was significantly higher in the elderly group than in the nonelderly group. Meanwhile, hyperthyroidism was observed only in the nonelderly group. No significant intergroup differences were observed in the incidence of perioperative complications occurring within four weeks postsurgery. Notably, the elderly group was more prone to develop perioperative intracerebral hemorrhage (odds ratio (OR) 3.14, 95% confidence interval (CI) 0.45-13.5) than the nonelderly group. During a median follow-up period of 7.8 years, the incidence of stroke recurrence occurring later than four weeks postsurgery was not significantly different between the groups (hazard ratio, 1.19; 95% CI 0.133-10.6). The prevalence of independent outcomes (76.9% vs. 90.4%, P = 0.14) and mortality (7.7% vs. 1.4%, P = 0.21) did not differ significantly between the elderly and nonelderly groups, respectively. Perioperative intracerebral hemorrhage may be common in the elderly and should be considered to achieve a favorable surgical outcome.

Neurovascular considerations in patients with Down syndrome and moyamoya syndrome.

In this article, we describe a rare and complex case of moyamoya syndrome in a 7-year-old boy with Down syndrome and atlantoaxial subluxation. The patient presented with an ischemic stroke in the left hemisphere and cervical cord compression with increased cord edema. Diagnostic digital subtraction angiography revealed unique patterns of vascular involvement, with retrograde flow through the anterior spinal artery, ascending cervical artery, occipital artery, and multiple leptomeningeal arteries compensating for bilateral vertebral artery occlusion. This case underscores the underreported phenomenon of upward retrograde flow through the anterior spinal artery in bilateral vertebral artery occlusion. We address the rare manifestation of posterior circulation involvement in moyamoya syndrome, highlighting the importance of considering atlantoaxial instability as a contributing factor, as the absence of atlantoaxial stability is a risk factor for vertebral artery dissection. This study contributes valuable insights into the intricate relationship of moyamoya syndrome, Down syndrome, and atlantoaxial instability, urging clinicians to consider multifaceted approaches in diagnosis and treatment. It also emphasizes the potential significance of the anterior spinal artery as a compensatory pathway in complex vascular scenarios.

Complications associated with combined direct and indirect bypass in Moyamoya Disease: A meta-analysis.

Bypass revascularization helps prevent complications in Moyamoya Disease (MMD). To systematically review complications associated with combined direct and indirect (CB) bypass in MMD and analyze differences between the adult and pediatric populations. A systematic literature review was conducted per PRISMA guidelines. PUBMED, Cochrane Library, Web of Science, and CINAHL, were queried from January 1980 to March 2022. Complications were defined as any event in the immediate post-surgical period of a minimum 3 months follow-up. Exclusion criteria included lack of surgical complication reports, non-English articles, and CB unspecified or reported separately. 18 final studies were included of 1580 procured. 1151 patients (per study range = 10-150, mean = 63.9) were analyzed. 9 (50.0%) studies included pediatric patients. There were 32 total hemorrhagic, 74 total ischemic and 16 total seizure complications, resulting in a rate of 0.04 (95% CI 0.03, 0.06), 0.7 (95% CI 0.04, 0.10) and 0.03 (95% CI 0.02, 0.05), respectively. The rate of hemorrhagic complications in the pediatric showed no significant difference from the adult subgroup (0.03 (95% CI 0.01-0.08) vs. 0.06 (95% CI 0.04-0.10, p = 0.19), such as the rate of ischemic complications (0.12 (95% CI 0.07-0.23) vs. 0.09 (95% CI 0.05-0.14, p = 0.40). Ischemia is the most common complication in CB for MMD. Pediatric patients had similar hemorrhagic and ischemic complication rates compared to adults.

Intellectual function and memory in children with moyamoya disease: relationship between Wechsler Intelligence Scale and Benton Visual Retention Test scores and regional cerebral blood flow.

OBJECTIVE: Intellectual function declines in about 30% of children with moyamoya disease (MMD). Memory function underpins higher order brain function, but the relationship between intellectual function and memory in pediatric MMD patients has not been well studied. This study aimed to investigate correlations between scores on the Wechsler Intelligence Scale for Children (WISC) and the Benton Visual Retention Test (BVRT), a visual memory test that can be administered to children, in children with MMD. Relationships between intellectual function or memory and regional cerebral blood flow (rCBF) have also not been well clarified in pediatric MMD patients. The authors also investigated associations between WISC or BVRT scores and rCBF in various brain regions. METHODS: WISC and BVRT scores and rCBF were assessed in 17 children with ischemic-onset MMD before revascularization. Single-photon emission CT with 123I-iodoamphetamine was used to measure rCBF. Relationships between WISC and BVRT scores were evaluated using Spearman's correlation coefficient and multivariate linear regression analysis. Cutoff values were identified for BVRT scores. Sensitivity and specificity were calculated to predict full-scale intelligence quotient (FSIQ) > 85 or ≤ 85. Associations between rCBF and WISC or BVRT scores were evaluated using linear regression analysis. RESULTS: BVRT scores were significantly correlated with FSIQ and scores on the Working Memory Index (WMI), Processing Speed Index, and Verbal Comprehension Index (VCI)/Verbal Intelligence Quotient (VIQ) of WISC. Multivariate linear regression revealed that number correct score and number of errors score of BVRT were associated with FSIQ. As cutoff values, a number correct score of 5 and a number of errors score of 8 offered the most reliable predictors of FSIQ > 85 and ≤ 85, respectively. FSIQ correlated positively with rCBF in the right and left hemispheres, right and left ganglia, right and left thalamus, right and left cerebellum, right middle cerebral artery (MCA) territory, pons, and vermis. WMI score was positively associated with rCBF in the right hemisphere, right anterior cerebral artery territory, right MCA territory, right basal ganglia, right and left thalamus, right and left cerebellum, pons, and vermis. CONCLUSIONS: BVRT score correlated well with WISC index scores, suggesting that BVRT may be helpful in screening for intellectual impairments in children with MMD. In the MCA territory, basal ganglia, thalamus, cerebellum, pons, and vermis, rCBF associated well with WISC index scores, suggesting that reduced rCBF in relevant brain regions may influence intellectual function.

Prevention of postoperative stroke in pediatric moyamoya patients: a standardized perioperative care protocol.

OBJECTIVE: Perioperative stroke is a major complication of revascularization surgery in patients with moyamoya. Vomiting is common after neurosurgical procedures and may result in acute changes in intracranial pressure and cerebral blood flow. The authors instituted a standardized perioperative nausea and vomiting protocol for children with moyamoya undergoing indirect bypass surgery at their institution and analyzed its association with perioperative stroke. They hypothesized that instituting a standardized perioperative nausea and vomiting protocol would be associated with reduction in the number of perioperative strokes in children with moyamoya undergoing indirect bypass surgery. METHODS: The authors retrospectively reviewed consecutive cases of children and young adults with moyamoya who underwent indirect bypass surgery before and after implementation of a new perioperative nausea and vomiting protocol at a single institution. They compared the rate of strokes in the perioperative period (postoperative days 0 and 1) in the 31 months following implementation to 31 months prior to implementation using Fisher's exact test. RESULTS: The median ages pre- and postimplementation were 8.5 (IQR 4-12) years and 8.3 (IQR 5-15) years, respectively. There were no significant differences between the cohorts in disease severity or other potentially confounding factors. In the 31 months prior to initiation of the perioperative nausea and vomiting protocol, there were 5 strokes in 137 surgically treated hemispheres (3.6%). After initiation of the protocol, there were no strokes in 114 surgically treated hemispheres (p = 0.065). CONCLUSIONS: Instituting a standardized perioperative nausea and vomiting protocol was associated with reduction in perioperative strokes in children with moyamoya treated with indirect bypass surgery.

Ivy Sign: Usefulness in Diagnosis and Prognosis Prediction of Moyamoya Disease.

BACKGROUND: Moyamoya disease (MMD) cannot be found commonly as a rare type compared with other vascular disease, such as aneurysm. However, it cannot be ignored for its high fatality and disability rates. In addition, exact pathogenesis study of this disease is still on the way. The ivy sign is always observed in MMD, but the clinical importance of this sign in MMD isn't clearly known. The main purpose of this research was to specifically investigate the clinical significance. METHODS: In this retrospective cohort study to gather the baseline clinical and imaging study, the patients with MMD were hospitalized from January 2016 to 2020. In the analysis, univariate and multivariate logistic regression was used to testify whether ivy sign was independently associated with MMD characteristics including cerebrovascular morphology, cerebral hemodynamics, cerebrovascular events, and postoperative collateral formation (PCF). RESULTS: We included 156 patients with 312 hemispheres. As for the result of multivariate logistic regression analysis, we could discover a fact that ivy sign was tightly connected to the Suzuki stage ≥IV (odds ratio [OR], 1.386; 95% confidence interval [CI], 1.055-1.822; P = 0.019), cerebral blood flow (CBF) decreased type (OR, 2.330; 95% CI, 1.733-3.133; P = 0.000), age acted as a protective factor for CBF (OR, 0.966; 95% CI, 0.946-0.986; P = 0.001), the elder was more likely associated with decreased CBF. Ivy sign also played a significant role in ischemic cerebrovascular events (OR, 5.653; 95% CI, 3.092-10.336; P = 0.003), their remarkable connection could be seen on the study. We could also find that ivy sign was closely connected to the good PCF (OR, 2.830; 95% CI, 1.329-6.027; P = 0.007), and we couldn't ignore the fact that age was associated with good PCF as well (OR, 0.933; 95% CI, 0.882-0.987; P = 0.015). DISCUSSION: We could be more aware of the connection between ivy sign and Moyamoya disease from this study in order to implement diagnosis, treatment, and prognosis more efficiently.

Posterior cerebral territory ischemia in pediatric moyamoya: Surgical techniques and long-term clinical and radiographic outcomes.

PURPOSE: To describe a surgical technique for posterior cerebral revascularization in pediatric patients with moyamoya arteriopathy. Here, we describe the clinical characteristics, surgical indications, operative techniques, and clinical and radiographic outcomes in a series of pediatric patients with moyamoya disease affecting the posterior cerebral artery (PCA) territory. METHODS: A retrospective single-center series of all pediatric patients with moyamoya disease who presented to our institute between July 2009 through August 2019 were reviewed. The clinical characteristics, surgical indications, operative techniques, and long-term clinical and radiographic outcomes of pediatric moyamoya patients with PCA territory ischemia were collected and analyzed. RESULTS: A total of 10 PCA revascularization procedures were performed in 9 patients, 5 female, ages 1 to 11.1 years (average 5.2 years). Complications included 1 stroke, with no infections, hemorrhages, seizures, or deaths. One patient had less than 1 year of radiographic and clinical follow-up. In 8 of 9 patients with at least 1 year of radiographic follow-up, there was engraftment of surgical vessels present in all cases. No new strokes were identified on long-term follow-up despite the radiographic progression of the disease. In the 8 cases available for analysis, the average follow-up was 50.8 months with a range of 12 to 117 months. CONCLUSIONS: PCA territory ischemia in patients with progressive moyamoya disease can be surgically treated with indirect revascularization. Here, we describe our experience with PCA revascularization procedures for moyamoya disease, including pial pericranial dural (PiPeD) revascularization and pial synangiosis utilizing the occipital artery. These surgical options may be useful for decreasing the risk of stroke in pediatric moyamoya patients with severe posterior circulation disease.

Outcomes after surgical revascularization for adult Moyamoya disease: A Southeast Asian tertiary centre experience.

There are numerous studies on the natural history and outcomes of adult Moyamoya disease (MMD) in the literature, but limited data from Southeast Asian cohorts. Hence, we aimed to retrospectively review the clinical characteristics and outcomes after surgical revascularization for adult MMD in our Southeast Asian cohort. Patients were included if they were above 18 years old at the first surgical revascularization for MMD, and underwent surgery between 2012 and 2022 at the National University Hospital, Singapore. The outcomes were transient ischemic attack (TIA), ischemic stroke, intracerebral hemorrhage, and all-cause mortality during the postoperative follow-up period. In total, 26 patients who underwent 27 revascularization procedures were included. Most patients were of Chinese ethnicity, and the mean (SD) age at the time of surgery was 47.7 (12.6) years. The commonest clinical presentation was intracerebral hemorrhage, followed by TIA and ischemic stroke. Direct revascularization with superficial temporal artery-middle cerebral artery (STA-MCA) bypass was the most common procedure (24/27 surgeries, 88.9 %). The mean (SD) follow-up duration was 4.2 (2.5) years, during which the overall incidence of postoperative TIA/stroke was 25.9 % (7/27 surgeries), with most cases occurring within 7 days postoperatively. There were no mortalities during the postoperative follow-up period. Risk factors for 30-day postoperative TIA/stroke included a higher number of TIAs/strokes preoperatively (p = 0.044) and indirect revascularization (p = 0.028). Diabetes mellitus demonstrated a trend towards an increased risk of 30-day postoperative TIA/stroke, but this was not statistically significant (p = 0.056). These high-risk patients may benefit from more aggressive perioperative antithrombotic and hydration regimens.

Effect of thin-split encephalomyosynangiosis on transient neurological events in revascularization surgery for pediatric patients with moyamoya disease.

OBJECTIVE: Transient neurological events (TNEs) are among the most important events after revascularization surgery in pediatric patients with moyamoya disease (MMD). Although hemodynamic changes and crying are representative factors of TNEs, brain compression by encephalomyosynangiosis (EMS) is another important cause of TNEs. Therefore, the authors assumed that making the EMS as thin as possible reduces the frequency of TNEs. However, thin-split EMS can lead to insufficient development of collateral vessels. This study aimed to evaluate the effects of thin-split EMS in combined revascularization surgery on postoperative outcomes in pediatric patients with MMD. METHODS: The authors retrospectively included 56 consecutive combined revascularization surgeries in the anterior cerebral circulation in pediatric patients with MMD. These surgeries were classified into the former group and thin-split EMS group. The temporal muscle was halved in the former EMS group and split as thinly as possible in the thin-split EMS group. The authors performed between-group comparisons of postoperative stroke events and TNEs during the acute period and the development of collateral flow and stroke events during the chronic period. RESULTS: Former and thin-split EMS procedures were performed in 37 and 19 patients, respectively. TNEs without crying or hemodynamic changes were observed significantly less frequently in the thin-split EMS group than in the former EMS group (0 [0.0%] in the thin-split EMS group vs 9 [24.3%] in the former EMS group, p = 0.021). There were no significant between-group differences in the development of indirect bypass during the chronic period (good: 34 [91.9%] and poor: 3 [8.1%] in the former EMS group vs good: 16 [84.2%] and poor: 3 [15.8%] in the thin-split EMS group; p = 0.397). Additionally, there were no significant between-group differences in the incidence of chronic clinical events, including death or stroke. CONCLUSIONS: Thin-split EMS can reduce TNEs that do not accompany crying or hemodynamic changes. Furthermore, the procedure has sufficient prevention effects against stroke events during the chronic postoperative period in pediatric patients with MMD.

Moyamoya Angiopathy: An Underdiagnosed Cause of Ischemic Stroke in a Tunisian Pediatric Cohort.

BACKGROUND: Moyamoya angiopathy is a rare cerebral vasculopathy and an underdiagnosed cause of arterial ischemic stroke in children. We aim to report the clinical and radiological presentations in a Tunisian pediatric cohort. METHODS: We identified moyamoya angiopathy in pediatric patients managed at the Child Neurology Department of Hedi Chaker Sfax University Hospital between 2008 and 2020 and reviewed their clinical and radiological data as well as their evolutionary profile. RESULTS: We collected 14 patients with median age 40.6 months and a female predominance (sex ratio of 0.75). An arterial ischemic stroke (AIS) revealed the disease in all patients, with the major symptom being a motor deficit. Symptoms related to a transient ischemic attack before the diagnostic consultation were reported in four patients. Carotid territory was, clinically and radiologically, the most frequently involved. Brain magnetic resonance imaging with angiography was performed in 12 patients confirming the diagnosis by revealing the development of collateral vessels. All the investigations concluded to moyamoya disease in 57.2% and moyamoya syndrome in 42.8%. The latter was related to Down syndrome in five patients and neurofibromatosis type 1 in one patient. With a mean follow-up of 2.35 years, two patients had at least two more AISs during the first two years following diagnosis and 42.8% of patients were diagnosed with vascular or poststroke epilepsy. Full recovery was noted in 14.3% of cases. CONCLUSIONS: Moyamoya angiopathy in children is a serious condition that needs to be recognized due to the high risk of recurrent ischemic strokes.