Pediatric moyamoya disease: An analysis of 410 consecutive cases

Combined gene therapy with vascular endothelial growth factor plus apelin in a chronic cerebral hypoperfusion model in rats

OBJECTIVE

The aim of this study was to evaluate whether combined gene therapy with vascular endothelial growth factor (VEGF) plus apelin during indirect vasoreconstructive surgery enhances brain angiogenesis in a chronic cerebral hypoperfusion model in rats.

METHODS

A chronic cerebral hypoperfusion model induced by the permanent ligation of bilateral common carotid arteries (CCAs; a procedure herein referred to as “CCA occlusion” [CCAO]) in rats was employed in this study. Seven days after the CCAO procedure, the authors performed encephalo-myo-synangiosis (EMS) and injected plasmid(s) into each rat's temporal muscle. Rats were divided into 4 groups based on which plasmid was received (i.e., LacZ group, VEGF group, apelin group, and VEGF+apelin group). Protein levels in the cortex and attached muscle were assessed with enzyme-linked immunosorbent assay (ELISA) on Day 7 after EMS, while immunofluorescent analysis of cortical vessels was performed on Day 14 after EMS.

RESULTS

The total number of blood vessels in the cortex on Day 14 after EMS was significantly larger in the VEGF group and the VEGF+apelin group than in the LacZ group (p < 0.05, respectively). Larger vessels appeared in the VEGF+apelin group than in the other groups (p < 0.05, respectively). Apelin protein on Day 7 after EMS was not detected in the cortex for any of the groups. In the attached muscle, apelin protein was detected only in the apelin group and the VEGF+apelin group. Immunofluorescent analysis revealed that apelin and its receptor, APJ, were expressed on endothelial cells (ECs) 7 days after the CCAO.

CONCLUSIONS

Combined gene therapy (VEGF plus apelin) during EMS in a chronic cerebral hypoperfusion model can enhance angiogenesis in rats. This treatment has the potential to be a feasible option in a clinical setting for patients with moyamoya disease.

Incidence, clinical features, and treatment of familial moyamoya in pediatric patients: a single-institution series

OBJECTIVE Limited data exist on familial moyamoya in children. The purpose of this study was to characterize presentation and outcomes of pediatric moyamoya patients who have relatives diagnosed with moyamoya. METHODS The authors performed a single-institution retrospective analysis of a case series including all surgically treated children with moyamoya with first- or second-degree relatives with moyamoya. Clinical and radiographic characteristics were analyzed, along with surgical outcomes. RESULTS A total of 537 patients underwent surgery for moyamoya during the study period. Eighteen of those patients (3.4% of the total series) had moyamoya and a family history of moyamoya and were included in this study. Of these 18 patients, 14 were non-twin siblings, and the remaining 4 represented 2 pairs of identical (affected) twins. The presentation was predominantly ischemic (72%), but 4 patients (33%) were asymptomatic when they were found to have moyamoya. Bilateral disease was present in 13 patients (72%). Radiographic stroke prevalence (67%), Suzuki grade (3.3), and angiographic findings were comparable to findings in nonfamilial moyamoya patients. Thirty revascularization procedures were performed, with a 3.3% operative stroke rate per hemisphere and no new strokes in an average follow-up period of 4.5 years. CONCLUSIONS In a North American surgical series, familial moyamoya existed in 3.4% of cases, and was distinguished by manifesting in a broad range of ethnic groups, with a higher proportion of male patients and increased rates of asymptomatic and unilateral disease in comparison to nonfamilial moyamoya. Screening indications remain controversial and the current data are used to suggest guidelines. Surgical therapy is warranted, effective, and durable in these patients, but patients should be carefully selected.

Hemodynamic Changes after Unilateral Revascularization for Moyamoya Disease: Serial Assessment by Quantitative Magnetic Resonance Angiography

BACKGROUND: Ultrasonic flow meters and quantitative magnetic resonance angiography quantitatively assess flow during hemodynamic evaluation of cerebral ischemia. Although their reliability and reproducibility have been verified, their clinical impact in moyamoya disease has rarely been reported.

OBJECTIVE: To investigate flow measurement outcomes in moyamoya disease patients pre- and postoperatively through a retrospective observational study.

METHODS: We evaluated 41 patients undergoing their first revascularization surgery who were followed ≥6 mo. Hemodynamic parameters were recorded preoperatively, at 1 and 6 mo postoperatively, and at the last follow-up. Demographic factors, Suzuki stage, and stroke development were also analyzed.

RESULTS: Patients’ median age was 37 yr (interquartile range [IQR], 27-43), and 16 (39.0%) patients were men. During follow-up, 9 (22.0%) patients experienced postoperative stroke (4 major strokes). Hemodynamic status was improved in 34 (82.9%) patients at the 6-mo follow-up. Median intraoperative flow was 41 mL/min (IQR, 25-59). Bypass flow peaked at 6 mo (median, 67 mL/min; IQR, 35-99). At the 1- and 6-mo follow-ups, ipsilateral hemispheric flow was significantly increased. The median proportion of posterior circulation at 6 mo was 44.4%, significantly lower than the preoperative proportion (50.1%). Abundant intraoperative bypass flow was associated with hemodynamic improvement, while low contralateral hemispheric flow was related with immediate postoperative ischemic stroke.

CONCLUSION: Ipsilateral hemispheric flow was increased during 6-mo follow-up, and posterior circulation flow burden was diminished. Abundant intraoperative bypass flow was associated with postoperative hemodynamic improvement. Low preoperative contralateral hemispheric flow was related with immediate postoperative ischemic stroke.

The Efficacy of Single Barrel Superficial Temporal Artery-middle Cerebral Artery Bypass in Treatment of Adult Patients with Ischemic-type Moyamoya Disease

OBJECTIVE

So far, there is no study answering the question of which type of surgical technique is practically the most useful in the treatment of adult patients with ischemic type moyamoya disease (MMD). We evaluated the efficacy of single barrel superficial temporal artery (STA)-middle cerebral artery (MCA) bypass in the treatment of adult patients with ischemic type MMD by retrospectively collecting clinical and radiological data.

MATERIALS AND METHODS

A retrospective review identified 31 adult patients who underwent 43 single barrel STA-MCA bypass procedures performed for treatment of ischemic-type MMD between 2006 and 2014. The male to female ratio was 17:14 and the mean age was 41 years (range, 21-65 years). Peri-operative complications, angiographic and clinical outcomes were analyzed retrospectively.

RESULTS

The permanent neurological morbidity and mortality rates were 2.3% and 0%, respectively. During the observation period of a mean of 35 months (range, 12-73 months), 29 patients (93.5%) had no further cerebrovascular events and transient ischemic attack occurred in two patients (6.5%), resulting in an annual stroke risk of 2.2%. Follow-up computed tomography perfusion (CTP) (mean, 18.4 months after surgery) documented improved cerebral hemodynamics in the revascularized hemispheres (p < 0.001). Post-operative patency was clearly verified in 38 bypasses (88.4%) of 43 bypasses on follow-up imaging (mean, 16.5 months).

CONCLUSION

Our results suggest that single barrel STA-MCA bypass with wide dural opening is safe and durable method of cerebral revascularization in adult patients with ischemic type MMD and can be considered as a potential treatment option for adult patients with ischemic type MMD.

Direct versus indirect revascularization procedures for moyamoya disease: a comparative effectiveness study

OBJECTIVE Moyamoya disease (MMD) is a chronic cerebrovascular disease that can lead to devastating neurological outcomes. Surgical intervention is the definitive treatment, with direct, indirect, and combined revascularization procedures currently employed by surgeons. The optimal surgical approach, however, remains unclear. In this decision analysis, the authors compared the effectiveness of revascularization procedures in both adult and pediatric patients with MMD. METHODS A comprehensive literature search was performed for studies of MMD. Using complication and success rates from the literature, the authors constructed a decision analysis model for treatment using a direct and indirect revascularization technique. Utility values for the various outcomes and complications were extracted from the literature examining preferences in similar clinical conditions. Sensitivity analysis was performed. RESULTS A structured literature search yielded 33 studies involving 4197 cases. Cases were divided into adult and pediatric populations. These were further subdivided into 3 different treatment groups: indirect, direct, and combined revascularization procedures. In the pediatric population at 5- and 10-year follow-up, there was no significant difference between indirect and combination procedures, but both were superior to direct revascularization. In adults at 4-year follow-up, indirect was superior to direct revascularization. CONCLUSIONS In the absence of factors that dictate a specific approach, the present decision analysis suggests that direct revascularization procedures are inferior in terms of quality-adjusted life years in both adults at 4 years and children at 5 and 10 years postoperatively, respectively. These findings were statistically significant (p < 0.001 in all cases), suggesting that indirect and combination procedures may offer optimal results at long-term follow-up.

Ocular Features and Visual Outcome in Children with Moyamoya Disease and Moyamoya Syndrome: A Case Series

Moya Moya Disease (MMD) is characterised by idiopathic vasculopathy affecting the terminal internal carotid arteries resulting in the formation of extensive collaterals at the base of the brain, leptomeninges and parenchymal regions with resultant infarcts and bleeds. Four children presented with clinico-radiological features suggestive of Moyamoya disease/syndrome. This includes global developmental delay, recurrent seizures, transient ischaemic attacks and impaired vision. The first patient had vision of 6/15 in both eyes with bilateral optic disc pallor. Second case also had bilateral optic disc pallor with arteriolar attenuation, but had vision of perception of light only in both eyes. The third child had vision of 6/60 with alternate divergent squint and clinical features suggestive of Neurofibromatosis 1 (NF 1). Fourth patient presented with poor fixation in both eyes with bilateral total cataract. He underwent bilateral cataract surgery with intraocular lens implantation and vision improved to 2/60 with good fixation. We also describe their medical and neurosurgical interventions in this report.

RNF213 as the major susceptibility gene for Chinese patients with moyamoya disease and its clinical relevance

OBJECTIVE Moyamoya disease (MMD) is a rare, genetically heterogeneous cerebrovascular disease. The authors conducted a genetic study of really interesting new gene (RING) finger protein 213 ( RNF213); actin alpha 2 ( ACTA2); BRCA1/BRCA2-containing complex subunit 3 ( BRCC3); and guanylate cyclase 1, soluble, alpha 3 ( GUCY1A3) as well as a clinical phenotype analysis in Chinese MMD patients to determine whether genetic differences are responsible for the different clinical features that appear in MMD in different ethnicities. METHODS A panel was designed to identify disease-causing mutations in MMD genes and those involved in related disorders ( RNF213, ACTA2, BRCC3, and GUCY1A3). The panel was used to detect disease-causing mutations in 255 Chinese MMD patients. Genotype and allele frequencies were compared between patients and 300 controls. A mutation segregation analysis was performed in 34 families, and genotype-phenotype correlations were made. RESULTS Twenty-seven rare missense variants of RNF213 were identified and were not found in controls. Among them, p.R4810K was identified in 31.4% of patients (80 of 255) with MMD. Significantly higher frequencies of the A allele and G/A genotype of p.R4810K were observed in MMD patients compared with controls (χ² = 104.166, p < 0.000). Twenty-five rare variants were identified in 10.6% of patients (27 of 255) without p.R4810K variants. Segregation analysis supported an association between MMD and 3 variants. No possible disease-causing mutations were identified in ACTA2, BRCC3, or GUCY1A3. Compared with patients without the rare variants in RNF213, the p.R4810K heterozygous patients were younger at diagnosis (25 vs 29 years old, p = 0.049) and had more familial cases (24% vs 4.4%, p = 0.000), ischemic cases (81.3% vs 67.5%, p = 0.037), and involvement of the posterior cerebral artery (52% vs 32.5%, p = 0.007). CONCLUSIONS RNF213 is the major susceptibility gene in Chinese MMD patients. The spectrum of rare variants identified in Chinese MMD patients was diverse. Compared to patients without the rare variants in RNF213, the p.R4810K heterozygous patients exhibited different clinical features.

Moyamoya Disease: Treatment and Outcomes

Although the pathogenesis of moyamoya disease (MMD) has not been fully elucidated, the effectiveness of surgical revascularization in preventing stroke has been addressed by many studies. The main mechanism of surgical revascularization is augmenting the intracranial blood flow using an external carotid system by either direct bypass or pial synangiosis. This can improve resting cerebral blood flow as well as vascular reserve capacity. For direct revascularization, the superficial temporal artery is used as the donor artery in most cases, although the occipital artery may be used in limited cases. Usually, the cortical branch of the middle cerebral artery is selected as the recipient of direct anastomosis. As for indirect revascularization, various techniques using different kinds of connective tissues have been introduced. In some cases, reinforcing the anterior cerebral artery and the posterior cerebral artery territories can be considered. The effectiveness of surgical revascularization for preventing ischemic stroke had been generally accepted by many studies. However, for preventing hemorrhagic stroke, new evidence has been added by a recent randomized controlled trial. The incidence of peri-operative complications such as stroke and hyperperfusion syndrome seems to be high due to the nature of the disease and technical demands for treatment. Preventing and adequately managing these complications are essential for ensuring the benefits of surgery.

Moyamoya Disease: Epidemiology, Clinical Features, and Diagnosis

Moyamoya disease (MMD) is a chronic, occlusive cerebrovascular disease characterized by progressive stenosis at the terminal portion of the internal carotid artery and an abnormal vascular network at the base of the brain. Although its etiology remains unknown, recent genetic studies identified RNF213 in the 17q25-ter region as an important susceptibility gene of MMD among East Asian populations. Possibly because of genetic differences, MMD is relatively common in people living in East Asian countries such as Korea and Japan, compared to those in the Western Hemisphere. The prevalence of MMD appears to be slightly lower among Chinese, compared to Koreans or Japanese. There are two peaks of incidence with different clinical presentations, at around 10 years and 30-40 years. The peak appears to occur later in women than men. In children, ischemic symptoms, especially transient ischemic attacks, are predominant. Intellectual decline, seizures, and involuntary movements are also more common in this age group. In contrast, adult patients present with intracranial hemorrhage more often than pediatric patients. In patients with MMD, intracerebral hemorrhage is more often accompanied by intraventricular hemorrhage than in patients with hypertensive intracerebral hemorrhage. These different age peaks and different clinical presentations in each age group are also observed in MMD patients in the USA. Catheter angiography is the diagnostic method of choice. Magnetic resonance (MR) angiography and computed tomographic angiography are noninvasive diagnostic methods. High-resolution vessel wall MR imaging also helps diagnose MMD by revealing concentric vessel wall narrowing with basal collaterals.

Quantitative Assessment of Neovascularization after Indirect Bypass Surgery: Color-Coded Digital Subtraction Angiography in Pediatric Moyamoya Disease

BACKGROUND AND PURPOSE

For the postoperative follow-up in pediatric patients with Moyamoya disease, it is essential to evaluate the degree of neovascularization status. Our aim was to quantitatively assess the neovascularization status after bypass surgery in pediatric Moyamoya disease by using color-coded digital subtraction angiography.

MATERIALS AND METHODS

Time-attenuation intensity curves were generated at ROIs corresponding to surgical flap sites from color-coded DSA images of the common carotid artery, internal carotid artery, and external carotid artery angiograms obtained pre- and postoperatively in 32 children with Moyamoya disease. Time-to-peak and area under the curve values were obtained. Postoperative changes in adjusted time-to-peak (ΔTTP) and ratios of adjusted area under the curve changes (ΔAUC ratio) of common carotid artery, ICA, and external carotid artery angiograms were compared across clinical and angiographic outcome groups. To analyze diagnostic performance, we categorized clinical outcomes into favorable and unfavorable groups.

RESULTS

The ΔTTP at the common carotid artery increased among clinical and angiographic outcomes, in that order, with significant differences (P = .003 and .005, respectively). The ΔAUC ratio at the common carotid artery and external carotid artery also increased, in that order, among clinical and angiographic outcomes with a significant difference (all, P = .000). The ΔAUC ratio of ICA showed no significant difference among clinical and angiographic outcomes (P = .418 and .424, respectively). The ΔTTP for the common carotid artery of >1.27 seconds and the ΔAUC ratio of >33.5% for the common carotid artery and 504% for the external carotid artery are revealed as optimal cutoff values between favorable and unfavorable groups.

CONCLUSIONS

Postoperative changes in quantitative values obtained with color-coded DSA software showed a significant correlation with outcome scores and can be used as objective parameters for predicting the outcome in pediatric Moyamoya disease, with an additional cutoff value calculated through the receiver operating characteristic curve.

Long term outcome and predictors of ischemic stroke recurrence in adult moyamoya disease

OBJECTIVE

We sought to identify the clinical outcome and predictors for ischemic stroke recurrence in adults with symptomatic moyamoya disease (MMD).

METHODS

We analyzed 104 adult MMD patients with ischemic stroke or TIA registered at our institution. All patients underwent digital subtraction angiography and single photon emission computed tomography to measure disease severity and cerebral vascular reserve (CVR). A Cox regression model was used to identify predictors of recurrent ischemic stroke.

RESULTS

Fifty-nine patients were non-surgically treated and 45 patients were surgically treated. In the non-surgical group, the Kaplan-Meier estimate of ischemic stroke recurrence was 1.6% in the first year and 11.8% in the 5th year. Hypertension (hazard ratio [HR]=0.07, 95% confidence interval [CI] 0.01-0.99), diabetes (HR=35.16, 95% CI 2.61-474.16), presence of steno-occlusive lesion in posterior cerebral arteries (HR=17.53, 95% CI 2.02-152.43), and extended or global decreased CVR (HR=13.62, 95% CI 1.55-119.84) were independent predictors of recurrence. In the surgical group, the Kaplan-Meier estimate of ischemic stroke recurrence was 24.4% in the first year and 24.4% in the 5th year. Half of the recurred patients experienced recurrent ischemic strokes postoperatively. Diabetes was the only predictor of recurrent ischemic stroke (HR=6.17, 95% CI 1.31-29.14).

CONCLUSIONS

In non-surgically treated MMD, PCA stenosis and CVR were identified as predictors of ischemic stroke recurrence. Diabetes was an independent predictor of recurrent ischemic stroke in both non-surgical and surgically treated MMD groups.

Importance of RNF213 polymorphism on clinical features and long-term outcome in moyamoya disease

OBJECT Moyamoya disease (MMD) is an idiopathic cerebrovascular occlusive disorder prevalent in East Asia. In the pathogenesis of MMD, the important role of genetic factors is being elucidated, and RNF213 has recently been identified as a susceptibility gene for MMD. The aim of this retrospective study was to investigate the RNF213 genotype in patients with MMD and to determine their genotype-phenotype associations. METHODS The study involved 165 Korean MMD patients from 155 unrelated families who were diagnosed with MMD at a single center from 1995 to 2013. Their demographic, radiological, and clinical findings were evaluated. Direct sequencing of the major RNF213 single nucleotide polymorphisms was performed. The association of the common RNF213 variant with MMD risk was evaluated using historical controls for comparison. Correlations between RNF213 genotype and phenotype were statistically analyzed. RESULTS The c.14429G>A (p.R4810K) variant was identified in 125 (75.8%) of 165 MMD patients. Most patients (112) were heterozygous, and 13 patients had 2 copies of the c.14429G>A variant. A novel heterozygous variant, c.12086A>G (p.Q4029R), was found in 1 additional patient. The minor allele frequency of the c.14429G>A variant was significantly higher in the MMD group (138 [41.8%] of 330 patients) than in the control group (8 [1.36%] of 588 subjects; p < 0.001). The c.14429G>A (p.R4810K) variant significantly increased the risk of MMD in Korean patients, with an OR of 52.11 (p < 0.001) compared with controls. Moreover, c.14429G>A (p.R4810K) genotypes occurred more frequently in patients with a family history of MMD. The homozygous variant was highly associated with early-onset MMD (age at onset < 5 years), cerebral infarction at diagnosis, and cognitive impairment in long-term outcome. CONCLUSIONS The findings indicate that the c.14429G>A (p.R4810K) allele of RNF213 is strongly associated with Korean patients with MMD. The homozygous c.14429G>A (p.R4810K) variant is particularly related to early-onset MMD, severe symptomatic manifestations at diagnosis, and poor prognosis. This genotypic variant may be a useful biomarker for early-onset MMD or unstable MMD with cerebral infarction, which requires early diagnosis and revascularization treatment.

Posterior Cerebral Artery Insufficiency in Pediatric Moyamoya Disease

The majority of clinical studies on moyamoya disease (MMD) have focused on anterior circulation. The disease involvement of posterior circulation in MMD, mainly in the posterior cerebral artery (PCA), has been mentioned since the early 1980s, and it has been repeatedly emphasized as one of the most important factors related to poor prognosis in MMD. However, its clinical features and outcome have only been elucidated during the last few years. In this review, the angiographic definition of PCA stenosis is summarized. The clinical features are elucidated as being either early-onset or delayed-onset, according to the time of PCA stenosis diagnosis in reference to the anterior circulation revascularization surgeries. The surgical strategy and hypothesis on the mechanism of PCA stenosis is also briefly mentioned. It appears that some MMD patients may show PCA stenosis during the early or late course of the disease and that the presenting symptoms may vary. Because the hemodynamic compromise caused by PCA stenosis may respond well to surgical treatment, clinicians should be aware of the condition, especially during follow-up of MMD patients.

Circulating Vascular Progenitor Cells in Moyamoya Disease

Various approaches have been attempted in translational moyamoya disease research. One promising material for modeling and treating this disease is vascular progenitor cells, which can be acquired and expanded from patient peripheral blood. These cells may provide a novel experimental model and enable us to obtain insights regarding moyamoya disease pathogenesis. We briefly present the recent accomplishments in regard to the studies of vascular progenitor cells in moyamoya disease.

Cognitive Outcome of Pediatric Moyamoya Disease

Quality of life is the current trend and issue for the most of human diseases. In moyamoya disease (MMD), surgical revascularization has been recognized as the possible assistance to reduce the neurological insult. However, the progressive nature of the disease has been invincible so far. To improve the quality of life of MMD patients not only the protection from the neurological insult but also the maintenance or improvement of cognitive function is inevitable. For pediatric MMD patients, younger age or longer duration of disease is the key factor among the prognostic factors for bad neurological outcomes. Hence, 'the earlier, the better' is the most precious rule for treatment. Protection from neurological insult is very critical and foremost important to improve cognitive outcome. Clinicians need to know the neuropsychological profile of MMD patients for the care of whole person and make an effort to protect the patients from neurological insults to maintain or improve it.

Moyamoya Syndrome: A Window of Moyamoya Disease

Moyamoya-like vasculopathy develops in association with various systemic diseases and conditions, which is termed moyamoya syndrome. Relatively common diseases and conditions are related to moyamoya syndrome, including neurofibromatosis type 1, Down syndrome, thyroid disease, and cranial irradiation. Moyamoya syndrome shares phenotypical characteristics with idiopathic moyamoya disease. However, they differ in other details, including clinical presentations, natural history, and treatment considerations. The study of moyamoya syndrome can provide clinicians and researchers with valuable knowledge and insight. Although it is infrequently encountered in clinical practice, moyamoya-like vasculopathy can severely complicate outcomes for patients with various underlying diseases when the clinician fails to expect or diagnose moyamoya syndrome development. Furthermore, moyamoya syndrome could be used as a doorway to more enigmatic moyamoya disease in research. More comprehensive survey and investigation are required to uncover the secrets of all the moyamoya-like phenomena.

"STA-MCA bypass with encephalo-duro-myo-synangiosis combined with bifrontal encephalo-duro-periosteal-synangiosis" as a one-staged revascularization strategy for pediatric moyamoya vasculopathy

PURPOSE

Moyamoya vasculopathy progressively compromises cerebral blood flow resulting in chronic hypoperfusion. The middle cerebral artery (MCA) territory and the bifrontal areas are the regions most frequently affected. Although most techniques aim to only revascularize the MCA territory, augmentation of blood flow of the bifrontal areas is of importance in the pediatric moyamoya population since these regions play an important role in cognition, intellectual development, and in lower extremity and sphincter function. We recently described a one-staged surgical procedure combining revascularization of three regions, the MCA territory unilaterally and the frontal areas bilaterally. The purpose of this article is to report our surgical experience in eight children and to emphasize the rational for bifrontal revascularization.

METHODS

We report a case series consisting of eight children where the following surgical strategy was applied: (1) a direct superficial temporal artery-to-middle cerebral artery (STA-MCA) bypass with encephalo-duro-myo-synangiosis (EDMS) for unilateral MCA revascularization; in combination with (2) a bifrontal encephalo-duro-periosteal-synangiosis (EDPS) for bifrontal revascularization. Patients' characteristics and 30-day follow-up data are reported.

RESULTS

The patient group consisted of six girls and two boys (mean age 10.0, range 4.2-17.5 years): six children presented with moyamoya disease, two with moyamoya syndrome. We performed a one-staged revascularization of one MCA territory and both frontal areas in all patients. No significant complications occurred. Two patients experienced postoperative focal seizures, successfully treated with anti-epileptic medication.

CONCLUSIONS

The single-staged STA-MCA bypass with EDMS combined with bifrontal EDPS allowed revascularization of three regions (the MCA territory unilaterally and the frontal areas bilaterally) and may serve as an alternative and safe treatment option for pediatric moyamoya patients.

The natural clinical course of hemodynamically stable adult moyamoya disease

OBJECT

Moyamoya disease (MMD) is a rare cerebrovascular disease and its natural history is still unclear. The authors aimed to investigate the natural course of hemodynamically stable cases of adult MMD, with the analysis of stroke risk factors.

METHODS

Two hundred forty-one patients were included in this retrospective study. One hundred sixty-six (68.9%) were female, and mean age (± SD) at first visit was 41.3 ± 12.0 years (range 18-69 years). Unilateral involvement was identified in 33 patients, and 19 patients (7.9%) had a family history of MMD. According to the clinical presentations, patients were classified into hemorrhagic (n = 62, 25.7%), ischemic (n = 144, 59.8%), and asymptomatic (n = 35, 14.5%) groups. The mean duration of follow-up was 82.5 ± 62.9 months (range 7.3-347.0 months).

RESULTS

The annual stroke risk was 4.5%, and the annual risks of rebleeding in the hemorrhagic group and recurrent ischemic events in the ischemic group were 4.3% and 3.0%, respectively. There was no significant difference in cumulative stroke risk between the 3 groups (p = 0.461). Risk factors included thyroid disease for overall strokes (HR 2.56, 95% CI 1.16-5.67), initial hemorrhagic presentation for hemorrhagic strokes (HR 2.53, 95% CI 1.24-5.17), and initial ischemic presentation for ischemic strokes (HR 2.69, 95% CI 1.15-6.27). Familial MMD was a common risk factor for all types of stroke. Among the 3 clinical groups, the hemorrhagic group showed the worst clinical status at discharge and at most recent follow-up. Twenty-three patients (9.5%) eventually underwent revascularization surgery.

CONCLUSIONS

There was no statistically significant difference in the incidence of stroke in the different clinical groups; clinical status, however, was most severe in patients with hemorrhagic presentation. In patients who experienced stroke during the follow-up period, the stroke type tended to correspond to their initial presentation. Close follow-up is needed in patients with thyroid disease and a family history of MMD.

Characteristics of brain magnetic resonance images at symptom onset in children with moyamoya disease

OBJECTIVES

To clarify the characteristics of brain magnetic resonance imaging (MRI) and magnetic resonance angiography (MRA) at symptom onset in patients with childhood moyamoya disease (MD) according to developmental stage.

METHODS

In 26 childhood MD patients who underwent brain MRI and MRA within 3 months from symptom onset, MRA scores and grades and MRI findings from symptomatic hemispheres were summarized according to developmental stage: infancy (0-1 years, three patients), toddlerhood/preschool age (2-5 years, nine patients), school age (6-10 years, seven patients), and adolescence (11-18 years, seven patients).

RESULTS

Mean MRA score was 5.6, which was higher in adolescents (6.9). The most common MRA grade was grade 3, particularly in those under 10 years. Acute ischemic infarction presented in 17 patients (65%), was more common in patients below 5 years (83%) and was mainly in a gyral pattern (47%). Most hemorrhagic infarctions occurred in adolescents. Moyamoya vessels in the Sylvian valleys were apparent in 22 patients (85%), which were the most sensitive non-ischemic findings on T2 weighted images. The signal void in the distal internal carotid artery was diminished in 73% and apparent signal voids in basal ganglia were seen in three patients. The ivy sign was positive in 81% on fluid attenuated inversion recovery images and 69% on contrast-enhanced T1-weighted images in 21 and 16 patients, respectively.

CONCLUSIONS

Brain MRIs and MRAs at symptom onset in childhood MD have characteristic findings, which differ in different developmental stage.

Clinical Features, Surgical Treatment, and Long-Term Outcome in Pediatric Patients with Moyamoya Disease in China

Background: There was few detailed demographic and clinical data about Chinese patients with moyamoya disease. Here we describe the clinical features, surgical treatment, and long-term outcome of pediatric patients with moyamoya disease at a single institution in China. Methods: Our cohort included 288 pediatric patients with moyamoya disease. The demographic and clinical characteristics were obtained by retrospective chart review and long-term outcome was evaluated using the stroke status. Univariate and multivariate logistic regression analyses were performed to determine the risk factors for clinical outcome. The risk of subsequent stroke was determined using the Kaplan-Meier method. Results: The median age for the onset of symptoms was 8.0 years. The ratio of female to male patients was 1:1. Familial occurrence of moyamoya disease was 9.4%. The incidence of postoperative complications was 4.2%. Postoperative ischemic events were identified as predictors of unfavorable clinical outcome, while older age of symptom onset was associated with a favorable clinical outcome. The Kaplan-Meier estimate stroke risk was 5% in the first 2 years, and the 5-year-Kaplan-Meier risk of stroke was 9% after surgery for all patients treated with surgical revascularization. Overall, 86% of patients had an independent life with no significant disability. Conclusion: This long-term survey demonstrated that most surgically treated pediatric patients with MMD maintain good outcomes. Our results indicate that an early diagnosis and active intervention before the establishment of irreversible hemodynamic change are essential to achieve a favorable clinical outcome.

Patterns of cerebral ischemia in children with moyamoya

BACKGROUND

Moyamoya disease is characterized by progressive cerebrovascular stenosis with recurrent cerebral ischemic events. Transient ischemic attacks are often associated with hyperventilation in children with moyamoya, suggesting hypoperfusion rather than thrombotic vaso-occlusion as a prominent mechanism. The patterns of ischemia and severity of steno-occlusive disease in such children may elucidate these mechanisms.

METHODS

Children, 1 month to 18 years, with moyamoya, observed over 11 years were analyzed. A study neuroradiologist reviewed all presurgical neuroimaging. Ischemic injury was categorized into cortical, subcortical, and watershed infarction. Angiographic findings were staged using a standardized method.

RESULTS

Twenty children, 15 girls, median age 6.4 years, were included. All children had magnetic resonance imaging and angiography, and in 16, conventional angiography was available. All 40 hemispheres, in 20 children, were evaluated. The initial clinical presentation included neurological deficits in 17, recurrent transient ischemic attacks in 7, headache in 8, seizures in 8, and alteration in consciousness in 4 children. Infarcts were bilateral in 13 (65%) children (ischemia alone in 14, ischemic stroke with hemorrhagic transformation in two, and primary hemorrhage in two). Infarcts were cortical and/or subcortical in 13 (65%), both deep and cortical watershed in 11 (55%), and cortical watershed alone in 5 (25%) children. The predominant vascular territory involved was the middle cerebral artery. The internal carotid arterial system was involved in all, with stage IV being the most frequent angiographic stage.

CONCLUSIONS

Ischemic injury in deep watershed zones is common in childhood moyamoya and may reflect non-vaso-occlusive ischemic mechanisms. Location and severity of vascular involvement may correlate with various patterns of ischemic infarction in moyamoya disease and requires further study.

Myoblast-mediated gene therapy improves functional collateralization in chronic cerebral hypoperfusion

BACKGROUND AND PURPOSE

Direct extracranial-intracranial bypass surgery for treatment of cerebral hemodynamic compromise remains hindered by complications but alternative simple and safe indirect revascularization procedures, such as an encephalomyosynangiosis (EMS), lack hemodynamic efficiency. Here, the myoblast-mediated transfer of angiogenic genes presents an approach for induction of therapeutic collateralization. In this study, we tested the effect of myoblast-mediated delivery of vascular endothelial growth factor-A (VEGF) to the muscle/brain interface of an EMS in a model of chronic cerebral hypoperfusion.

METHODS

Permanent unilateral internal carotid artery-occlusion was performed in adult C57/BL6 mice with or without (no EMS) surgical grafting of an EMS followed by implantation of monoclonal mouse myoblasts expressing either VEGF164 or an empty vector (EV). Cerebral hemodynamic impairment, transpial collateralization, angiogenesis, mural cell investment, microvascular permeability, and cortical infarction after ipsilateral stroke were assessed by real-time laser speckle blood flow imaging, 2- and 3-dimensional immunofluorescence and MRI.

RESULTS

VEGF-expressing myoblasts improved hemodynamic rescue by day 14 (no EMS 37±21%, EV 42±9%, VEGF 48±12%; P<0.05 for VEGF versus no EMS and versus EV), together with the EMS take rate (VEGF 60%, EV 18.2%; P<0.05) and angiogenesis of mature cortical microvessels below the EMS (P<0.05 for VEGF versus EV). Importantly, functional and morphological results were paralleled by a 25% reduction of cortical infarction after experimental stroke on the side of the EMS.

CONCLUSIONS

Myoblast-mediated VEGF supplementation at the target site of an EMS could help overcome the clinical dilemma of poor surgical revascularization results and provide protection from ischemic stroke.

Long-Term Outcomes After Combined Revascularization Surgery in Adult Moyamoya Disease

Background and Purpose—

The surgical outcomes of adult moyamoya disease are rarely reported. We aimed to evaluate the long-term outcomes of combined revascularization surgery in patients with adult moyamoya disease.

Methods—

Combined revascularization surgery consisting of superficial temporal artery–middle cerebral artery anastomosis with encephalodurogaleosynangiosis was performed on 77 hemispheres in 60 patients. Clinical, angiographic, and hemodynamic states were evaluated retrospectively using quantitative methods preoperatively and postoperatively in the short-term (≈6 months) and long-term (≈5 years) periods. The mean clinical follow-up duration was 71.0±10.1 months (range, 60–104 months).

Results—

Clinical status improved until 6 months after surgery and remained stable thereafter, as assessed by the Karnofsky Performance Scale and modified Rankin Scale. The revascularization area relative to supratentorial area significantly increased in the long-term period compared with that in the short-term period (54.8% versus 44.2%; P <0.001). Cerebral blood flow in the territory of the middle cerebral artery improved in the short-term period compared with that in the preoperative period (68.7 versus 59.1; considering blood flow of the pons as 50; P <0.001) and thereafter became stable (65.5 in the long term; P =0.219). The annual risks of symptomatic hemorrhage and infarction were 0.4% and 0.2%, respectively, in the operated hemispheres.

Conclusions—

Combined revascularization surgery resulted in satisfactory long-term improvement in clinical, angiographic, and hemodynamic states and prevention of recurrent stroke.

The frequency of postoperative stroke in moyamoya disease following combined revascularization: a single-university series and systematic review

Object

Although combined direct and indirect anastomosis in patients with moyamoya disease immediately increases cerebral blood flow, the surgical procedure is more complex. Data pertinent to the postoperative complications associated with combined bypass are relatively scarce compared with those associated with indirect bypass. This study investigated the incidence and characteristics of postoperative stroke in combined bypass and compared them with those determined from a literature review to obtain data from a large population.

Methods

A total of 358 revascularization procedures in 236 patients were retrospectively assessed by reviewing clinical charts and radiological data. PubMed was searched for published studies on surgical treatment to determine the incidence of postoperative complications in a larger population.

Results

Seventeen instances of postoperative stroke were observed in 16 patients (4.7% per surgery, 95% CI 2.8%–7.5%). Postoperative stroke was more frequent (7.9% per surgery) in adults than in pediatric patients (1.7% per surgery, OR 4.07, 95% CI 1.12–14.7; p < 0.05). Acute progression of stenoocclusive changes were identified in the major cerebral arteries (anterior cerebral artery, n = 3; middle cerebral artery, n = 1; posterior cerebral artery, n = 2). The postoperative stroke rate was comparable with that (5.4%) determined from a literature search that included studies reporting more than 2000 direct/combined procedures. No differences in the stroke rates between the direct/combined and indirect procedures were found. In the literature review, direct/combined bypass was more often associated with excellent revascularization (angiographic opacification greater than two-thirds) than indirect bypass (p < 0.05).

Conclusions

This experience of 358 consecutive procedures is one of the largest series for which the postoperative stoke rate for direct/combined bypass performed with a unified strategy has been reported. A systematic review confirmed that the postoperative stroke rate for the direct/combined procedure was comparable to that for the indirect procedure.

In vivo evaluation of angiogenic activity and its correlation with efficacy of indirect revascularization surgery in pediatric moyamoya disease

Indirect revascularization is the most widely used treatment to induce angiogenesis in pediatric moyamoya disease (MMD). Molecular imaging methods targeted for angiogenesis have recently been developed. We performed angiogenesis imaging in indirect revascularization surgery for MMD to evaluate angiogenic activity and its correlation with treatment efficacy.

METHODS

Twelve patients with pediatric MMD were prospectively enrolled. Encephaloduroarteriosynangiosis surgery was conducted, and (68)Ga-Arg-Gly-Asp (RGD) PET was performed 3.7 ± 1.0 mo after surgery. Basal perfusion and stress perfusion (PStr) in the middle cerebral artery territory were evaluated by acetazolamide-stress brain perfusion SPECT using statistical probabilistic anatomic mapping, at preoperative, early postoperative, and long-term follow-up states. Angiogenic activity was assessed on the images in terms of maximal uptake ratio, volume of increased uptake, and uptake-volume product.

RESULTS

Basal perfusion and PStr were significantly improved after surgery. Increased angiogenic activity was observed in the revascularized area, mainly around the bony flap. Angiogenic activity gradually decreased with time and significantly correlated with the postoperative time interval (P = 0.0015 for maximal uptake ratio and 0.0069 for volume of increased uptake). It was estimated to normalize at 6.3 mo after surgery. Uptake-volume product was inversely correlated with PStr improvement at the early postoperative state (r = -0.5960, P = 0.0409) and also weakly correlated with PStr improvement at long-term follow-up (r = -0.5010, P = 0.1165).

CONCLUSION

Angiogenesis PET imaging with (68)Ga-RGD was successfully used for the assessment of angiogenic activity in indirect revascularization surgery for MMD, and angiogenic activation measured at approximately 3.7 mo after surgery was inversely correlated with perfusion improvement. The assessment of angiogenic activity using (68)Ga-RGD PET is expected to be effective for evaluating the mechanism or efficacy of revascularization treatment.

Involuntary movement in pediatric moyamoya disease patients: consideration of pathogenetic mechanism using neuroimaging studies

PURPOSE

Involuntary movement is a rare symptom of moyamoya disease (MMD). No consensus has been reached regarding its clinical features and pathogenetic mechanism. Therefore, pediatric MMD patients presenting with involuntary movement were retrospectively analyzed, focusing on the image findings.

METHODS

A total of 513 patients who were treated for MMD were reviewed. After exclusion of MMD syndromes and those with accompanying conditions related to involuntary movements, five patients (mean age: 11.6 years, range: 5-13 years) were evaluated.

RESULTS

All of the patients improved their symptoms rapidly after the indirect bypass operations to the contralateral hemisphere. All remained symptom-free during the long follow-up period. Comprehensive evaluation of the preoperative imaging findings failed to suggest a characteristic feature in common, corresponding to the existing hypotheses or a new hypothesis. Only one patient showed infarction preoperatively, and only one patient showed prominently enhanced collateral vessels in the basal ganglia. Although a decrease in vascular reserve was observed in all patients, the location and laterality were nonspecific.

CONCLUSION

There still appears to be confusion regarding the pathogenetic mechanism of involuntary movement in MMD with no repetitive, established imaging features to explain the phenomenon. Nonetheless, with its excellent response to surgical treatment, clinical awareness of this rare symptom of MMD should be emphasized as a differential diagnosis for secondary movement disorder in children.

Pediatric arterial ischemic stroke

PURPOSE OF REVIEW

This article aims to provide a broad overview of pediatric arterial ischemic stroke, from recognition and diagnosis to the short-term and long-term management based on current available literature.

RECENT FINDINGS

Arterial ischemic stroke in children represents a significant disorder with a concerning high rate of adverse outcomes, including potentially preventable recurrent stroke. Although awareness of pediatric stroke is increasing, diagnosis is still commonly delayed or missed altogether, particularly in younger children. Current vascular imaging techniques have limitations in accurate diagnosis of arteriopathies that are now recognized as an important cause of childhood stroke. Significant variability exists in treatment of pediatric stroke. Management is based on published consensus guidelines; however, individual children require an individualized approach.

SUMMARY

As pediatric stroke specialists become increasingly available, the collaboration of such experts on individual management is crucial. Definitive evidence-based treatment for pediatric stroke awaits the development of randomized controlled trials.

A case of acute traumatic subdural hematoma in a child with previous bilateral encephaloduroarteriosynangiosis

The authors report the case of a 5-year-old female with right-sided hemiparesis and aphasia secondary to moyamoya disease, who had previously undergone staged bilateral encephaloduroarteriosynangiosis procedures. A subsequent ground-level fall caused an acute traumatic subdural hematoma with mass effect and neurological decline. She underwent emergency hematoma evacuation and decompressive craniectomy, which required interruption of the superficial temporal artery that had been used for indirect bypass, followed later by autologous cranioplasty. There were no acute or long-term ischemic events related to the occurrence or treatment of the traumatic hematoma. Follow-up angiography revealed extensive spontaneous vascular collateralization in the field of the decompressive craniectomy and cranioplasty. The patient returned to her pre-injury neurological baseline.

Approach to acute ischemic stroke in childhood

OPINION STATEMENT

Acute ischemic stroke in childhood is a medical emergency. Prompt recognition and intervention is necessary to rescue potentially viable brain tissue, prevent complications, and minimize the risk of recurrent stroke. Conditions that could result in recurrent stroke such as cardiac thrombus or cervical artery dissection need to be identified and treated promptly. Although the care of childhood stroke is based largely on extrapolation from adults, an organized approach to the care of these children is critical to optimize outcome.

Contralateral progression and its risk factor in surgically treated unilateral adult moyamoya disease with a review of pertinent literature

BACKGROUND

The fate of the contralateral unaffected side of the surgically treated unilateral moyamoya disease (MMD) in adults has not been well described due to the limited number of cases and the heterogeneous ages and treatment methods. The aim of this study was to evaluate the contralateral angiographic progression rate and its risk factors in homogeneous adult MMD patients who underwent surgical revascularization, with a review of pertinent literature.

METHODS

Forty-one surgically treated unilateral MMD patients were retrospectively evaluated. We reviewed medical and radiological records including data on gender, age, hypertension (HTN), smoking, familial MMD, presenting symptom, surgical method, Suzuki stage, and contralateral progression. Then, we conducted univariate and multivariate analyses to determine risk factors.

RESULTS

Six of the 41 cases (14.6%) exhibited contralateral progression during the mean follow-up of 34 months. Four of those six patients (66.7%) were asymptomatic. Additional revascularization surgery was performed in the two symptomatic patients. The presence of a contralateral angiographic abnormality on initial angiography was a statistically significant risk factor for progression (OR, 49.00; p = 0.04). Younger age at diagnosis (32.7 ± 7.8 years in progression group vs. 42.5 ± 10.3 years in non-progression group, p = 0.046) was statistically significant in the univariate analysis, but age was not a significant factor in the multivariate analysis (p = 0.82). Other variables, such as gender (p = 0.13), HTN (p = 0.24), smoking (p = 0.47), and familial MMD (p = 0.20), did not show statistical significance.

CONCLUSIONS

The presence of a contralateral angiographic abnormality on initial angiography was a significant risk factor for progression in surgically treated unilateral adult MMD. Consequently, patients with contralateral abnormalities should be monitored closely.

Combined Bypass Technique for Contemporary Revascularization of Unilateral MCA and Bilateral Frontal Territories in Moyamoya Vasculopathy

Moyamoya vasculopathy (MMV) leads to chronic hypoperfusion predominantly in the middle cerebral artery (MCA) and anterior cerebral artery (ACA) territories. Most revascularization techniques focus on revascularization of the MCA territory. Augmentation of blood flow in the frontal area is important for neurocognition and lower extremity function. In this article we describe a new combined (direct and indirect) one-stage bypass technique consisting of a superficial temporal artery to middle cerebral artery (STA-MCA) bypass with encephalo-duro-synangiosis (EDS) for unilateral MCA revascularization, along with an encephalo-duro-periosteal-synangiosis (EDPS) for bifrontal blood flow augmentation. The strength of this technique is the revascularization of three vascular territories during a single surgical intervention: the MCA unilaterally; and the frontal territories bilaterally. Bifrontal EDPS may also be considered as a supplementary independent procedure for patients who previously underwent revascularization treatment in the MCA territory, but develop symptoms due to frontal hypoperfusion.

Posterior cerebral artery involvement in moyamoya disease: initial infarction and angle between PCA and basilar artery

PURPOSE

Moyamoya disease (MMD) is a chronic cerebrovascular occlusive disease, and progressive involvement of the posterior cerebral artery (PCA) has been reported. However, majority of MMD articles are presenting classic anterior circulation related issues. This study investigates the preoperative factors related to the long-term outcome of posterior circulation in MMD.

METHODS

Retrospective review of 88 MMD patients (166 PCAs in either hemisphere) without symptomatic disease involvement of PCA at initial diagnosis was done. Data at initial diagnosis regarding age, presence of infarction, status of the PCA, type of posterior communicating artery, and the angle between PCA and basilar artery were reviewed. Progressive stenosis of PCA was evaluated by symptom or radiological imaging during follow up.

RESULTS

During an average follow up of 8.3 years, 29 out of 166 (18 %) evaluated PCAs showed progressive disease involvement. The average time of progression from the initial operation was 4.9 years, with the latest onset at 10.8 years. The patients who showed progressive stenosis of the PCA tended to be younger, present with infarction, have smaller angle between PCA and basilar artery, and have asymptomatic stenosis of the PCA at initial presentation. However, multivariate analysis confirmed only the presence of initial infarction and a smaller angle between PCA and basilar artery to be significantly associated with progressive stenosis of PCA.

CONCLUSIONS

Involvement of PCA in MMD may occur in a delayed fashion, years after the completion of revascularization of anterior circulation. Persistent long-term follow-up regarding the posterior circulation is recommended.

Smooth-muscle progenitor cells isolated from patients with moyamoya disease: novel experimental cell model

OBJECT

Moyamoya disease (MMD) is a cerebrovascular occlusive disease affecting bilateral internal carotid termini. Smooth-muscle cells are one of the major cell types involved in this disease process. The characteristics of circulating smooth-muscle progenitor cells (SPCs) in MMD are poorly understood. The authors purified SPCs from the peripheral blood of patients with MMD and sought to identify differentially expressed genes (DEGs) in SPCs from these patients.

METHODS

The authors cultured and isolated SPCs from the peripheral blood of patients with MMD (n = 25) and healthy control volunteers (n = 22). After confirmation of the cellular phenotype, RNA was extracted from the cells and DEGs were identified using a commercially available gene chip. Real-time quantitative reverse transcription polymerase chain reaction was performed to confirm the putative pathogenetic DEGs.

RESULTS

The SPC-type outgrowth cells in patients with MMD invariably showed a hill-and-valley appearance under microscopic examination, and demonstrated high α-smooth muscle actin, myosin heavy chain, and calponin expression (96.5% ± 2.1%, 42.8% ± 18.6%, and 87.1% ± 8.2%, respectively), and minimal CD31 expression (less than 1%) on fluorescence-activated cell sorter analysis. The SPCs in the MMD group tended to make more irregularly arranged and thickened tubules on the tube formation assay. In the SPCs from patients with MMD, 286 genes (124 upregulated and 162 downregulated) were differentially expressed; they were related to cell adhesion, cell migration, immune response, and vascular development.

CONCLUSIONS

With adequate culture conditions, SPCs could be established from the peripheral blood of patients with MMD. These cells showed specific DEGs compared with healthy control volunteers. This study provides a novel experimental cell model for further research of MMD.

Postoperative epidural hematoma covering the galeal flap in pediatric patients with moyamoya disease: clinical manifestation, risk factors, and outcomes

OBJECT

Postoperative epidural hematoma (EDH), a blood collection between the inserted galeal flap and the overlying skull flap (epigaleal flap hematoma), is a frustrating complication of the surgical treatment of moyamoya disease (MMD) in pediatric patients. The symptoms of postoperative EDH are often similar to those of postoperative cerebral ischemia, and may cause confusion during clinical decision making. The authors designed this study to evaluate the incidence, clinical presentation, risk factors, and treatment outcomes of postoperative EDH in pediatric patients with MMD.

METHODS

A retrospective review of 148 pediatric patients with 250 craniotomies who underwent indirect bypass revascularization surgery between January 2002 and December 2006 was performed. This group consisted of 60 male and 88 female patients, and the mean age at surgery was 7.5 years (range 1-18 years).

RESULTS

Of the 250 craniotomies, postoperative EDH was detected in 32 cases. In 12 cases of EDH, surgical treatment was necessary (4.8% of 250 craniotomies). During the same period, 743 non-MMD craniotomy operations were performed. In 6 of these 743 operations, patients developed postoperative EDH that required surgical treatment, significantly less than the percentage of EDH requiring postoperative treatment in patients with MMD (0.8%, p < 0.001). The average interval between craniotomy surgery and the detection of EDH was 1.8 days (range 0-5 days) in patients with MMD and 0.5 days (range 0-2 days; p = 0.018) in the non-MMD craniotomy group. Postoperative EDH was observed in significantly fewer cases (17 of 191) when a subcutaneous drain (SCD) was inserted over the bone flap than in cases in which an SCD was not inserted (14 of 55; p = 0.001). The mean international normalized ratio of prothrombin time in the immediate postoperative blood test was 1.27 ± 0.17 in the EDH group and 1.20 ± 0.11 in the non-EDH group (values are expressed as the mean ± SD; p = 0.008). Central galeal flap tenting suture and immediate postoperative platelet count were not related to the incidence of postoperative EDH following pediatric MMD surgery.

CONCLUSIONS

Postoperative EDH is more likely to be found following craniotomy in patients with MMD than in those without MMD, and may occur in a delayed fashion. Insertion of an SCD and immediate correction of an abnormal value for international normalized ratio of prothrombin time can decrease the incidence of postoperative EDH following surgery for pediatric MMD.

Fatal hemorrhagic stroke in a Caucasian girl with moyamoya disease

INTRODUCTION

Moyamoya disease (MMD) is an extremely rare neurovascular disorder in Caucasian children. To the best of our knowledge, the aggressive variant including hemorrhagic malignant stroke and consecutive global ischemia has not been reported for this population before.

CASE REPORT

We present the case of an 11-year-old girl with sudden neurological deterioration due to intracerebral hemorrhage with early irruption into the ventricular system. MMD with extensive neovascularization was diagnosed by means of computed tomography and magnetic resonance imaging. Despite immediate ventricular drainage, intracranial pressure increased above the mean arterial pressure resulting in malignant bi-hemispheric ischemia. The girl died within 53 h after admission to hospital.

DISCUSSION

Intracerebral hemorrhage in young patients is often attributed to vascular malformation. This case shows that MMD may constitute a potential diagnosis in the case of sudden neurological deterioration and loss of consciousness, even in previously healthy children.

Early clinical characteristics according to developmental stage in children with definite moyamoya disease

The objective is to clarify the early clinical characteristics in childhood moyamoya disease (MD). Epidemiologic characteristics, symptoms and diagnostic rates were assessed in 64 children (0-18 years) with definite MD according to developmental stage: infancy (5; 0-1 years); toddlerhood/preschool age (22; 2-5 years); school age (29; 6-10 years); and adolescence (8; 11-18 years). The median ages at onset was 6.25 years and the female to male ratio was 1.9 (~2.5 in toddlerhood/preschool age and in adolescence, P=0.71). Previous headache was observed in 23% (14/64): frequently in school age (38%, P=0.02) and within 6 months before main symptoms (6/11). As an initial symptom, weakness was observed in 78% (50/64) mainly as transient ischemic attack (TIA, 61%) in limbs (90%) and unilaterally (82%). TIA was less frequent in infancy (40%, P=0.04). Seizure was observed in 27% (17/64): frequently in infancy (100%, P<0.01), as the focal type (71%), and in the right extremity (3:1). Isolated seizures without other symptoms was frequent in children ~5 years (P<0.01). Severe headache associated with MD was observed in 14% (9/64). Provoking events were positive in 42% (27/64): in school age, frequently during eating (28%); and in toddlerhood/preschool age, during crying (27%). The diagnostic rates at 3 and 12 months from symptom-onset were 39% (80% during infancy vs. 28% in school age, P=0.14) and 67%, respectively. Symptomatic progression at diagnosis was observed in 38% (24/64). Initial clinical characteristics in childhood definite MD differed according to developmental stage and from at diagnosis.

Pediatric Moyamoya disease

Background:

Moyamoya disease (MMD) is a progressive cerebrovascular occlusive disease of the bilateral internal carotid arteries that leads to a compensatory abnormal vascular network at the base of the brain. Its average annual incidence 0.54 per 100,000 population but it is the most common pediatric cerebrovascular disease in East Asia. The reported incidence in USA is approximately 0.086 per 100,000 patients.

Case Report:

We present a case of Moyamoya disease that was to detected in a 7-year-old female who presented with transient altered mental status.

Conclusions:

Moyamoya disease can be diagnosed if history, physical exam and brain imaging is highly suspicious. Conventional angiography remains the gold standard for diagnosis and aids in surgical planning for patients with suspected Moyamoya disease.

Clinical features, surgical treatment and long-term outcome in adult patients with Moyamoya disease in China

BACKGROUND

Moyamoya disease (MMD) develops mostly in Asian countries including Japan, Korea, mainland China and Taiwan. However, there are few detailed demographic and clinical data about Chinese patients with MMD. Currently, the most effective treatment in adult patients with MMD is unknown. There have only been a few small case series reporting on encephaloduroarteriosynangiosis (EDAS) in an adult population. Here we describe the clinical features, surgical treatment and long-term outcome of adults with MMD treated at a single institution in China.

METHODS

Our cohort included 470 adult patients with MMD. The demographic and clinical characteristics were obtained by retrospective chart review and long-term outcome was evaluated using the stroke status. The modified Rankin Scale (mRS) was used to determine the neurological functional outcome. Univariate and multivariate logistic regression analyses were performed to determine risk factors for postoperative morbidity and functional outcome. The risk of subsequent stroke was determined using the Kaplan-Meier method and Cox regression was used to determine risk factors for postoperative or subsequent strokes.

RESULTS

The median age for the onset of symptoms was 36.8 (range, 18-59) years. The ratio of female to male patients was 1:1 (231/239). Familial occurrence of MMD was 2.3%. The most common initial symptom was a cerebral ischemic event. The incidence of postoperative ischemic events or hemorrhage was 5.9% (9.8% of patients). Older age at symptom onset, posterior cerebral artery (PCA) involvement and the presence of transient ischemic attack (TIA) were identified as predictors of adverse postoperative events. The Kaplan-Meier estimate stroke risk was 10.1% in the first 2 years, and the 5-year Kaplan-Meier risk of stroke was 13% after surgery for all patients treated with surgical revascularization. Older age at symptom onset, PCA involvement and the presence of TIA were identified as predictors of postoperative or subsequent strokes. Overall, 73.2% of patients had an independent life with no significant disability, with the strongest predictor being the preoperative mRS score.

CONCLUSION

Clinical characteristics of adult MMD in China are different from those in other Asian countries. EDAS in adult patients with MMD carries a low risk, is effective at preventing future ischemic events and improves quality of life.

Risk factors and clinical outcomes of childhood ischemic stroke in a single Korean tertiary care center

A 10-year, retrospective review of the risk factors and clinical outcome of childhood ischemic stroke treated in a single tertiary care center was conducted. Sixty-two children were identified (33 boys and 29 girls), ages 1 month to 17 years. Risk factors included vasculopathy (35.5%), cardiac disease (17.4%), metabolic disorder (14.5%), infection (14.5%), and coagulopathy (1.6%). Nine patients (14.5%) had no identifiable cause of stroke and 1 patient had 2 risk factors. Hemiplegia (69.3%) and seizures (32.3%) were the most common presenting features, and seizures were significantly more frequent in children <12 months of age than in older children (71.4% vs 20.8%, P = .001). Recurrence of stroke occurred in 55.6% of patients with metabolic disorder, 33.3% of those with cardiac disease, and 19.0% of those with vasculopathy. Vasculopathy including moyamoya disease was the most important risk factor for ischemic stroke in Korea, and their prognosis were varied with the etiology of stroke.

Early diagnosis and surgical revascularization for a predictive case of moyamoya disease in a boy born to a moyamoya mother

Among patients with moyamoya disease, familial occurrence is observed in about 20%, suggesting the involvement of genetic factors. In this report, we describe the first predictive case of moyamoya disease in a boy born to a woman who underwent surgical revascularization for moyamoya disease when she was 3 years old. We educated the mother and her family not to miss his initial signs of the disease. His family could easily notice his brief episode of ischemic attack when he was 6 years old. He underwent superficial temporal artery-to-middle cerebral artery anastomosis and indirect bypass on both sides. The postoperative course was uneventful. In conclusion, it is quite important to educate the family not to miss the initial signs of disease in their offspring, at least when they have a genetic background of the disease, because early diagnosis and effective treatment are essential to improve the long-term outcome in pediatric patients.

Hemorrhagic moyamoya disease in children: clinical features and surgical outcome

OBJECTIVE

The clinical presentation of moyamoya disease (MMD) typically includes cerebral ischemia in children and intracranial hemorrhage in adults. Because of its rarity, the benefit of surgery in the hemorrhagic type of pediatric MMD has not been clearly established. The purpose of this study was to delineate the clinical features and surgical outcome of hemorrhagic MMD in children.

METHODS

Thirteen patients (six boys and seven girls with a combined mean age of 11.1 years and a range of 4-18 years) were retrospectively confirmed as having MMD with intracranial hemorrhage between 1988 and 2009. All of the patients underwent indirect bypass surgery that followed a relatively uniform scheme at a single institution. We retrospectively reviewed their clinical features and surgical outcome. The mean time of follow-up was 50.3 months (with a range of 3-99 months).

RESULTS

Six of the patients presented with intracerebral hemorrhage (ICH), and six others presented with intraventricular hemorrhage (IVH); the remaining patient presented with both ICH and IVH. Preoperative angiography demonstrated that the patients were in various stages of the disease, but the majority of the patients (i.e., 16 of the 26 hemispheres) were in stage 3 with abundant moyamoya vessels (MMV). Three of four patients who presented with a history of prior hemorrhage or infarct exhibited a poor clinical outcome. Five patients with good revascularization had a decreased degree of MMV in their follow-up angiogram and showed good clinical outcome. Recurrent bleeding occurred after surgery in one patient.

CONCLUSIONS

Revascularization surgery may have a role for prevention of rebleeding and cerebral infarction in pediatric MMD patients who present with intracranial hemorrhage.