Serial intelligence test scores in pediatric moyamoya disease

Neuropsychiatric Symptoms of Moyamoya Disease: Considerations for the Clinician

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

Prevalence and Associations of Cognitive Impairment in Adult Patients with Moyamoya Disease: A Systematic Review and Meta-Analysis

BACKGROUND

Cognitive impairment, and in the long term Alzheimer's disease, vascular, or mixed dementia, are potential complications of moyamoya disease (MMD), of which the prevalence and associations are not well established.

OBJECTIVE

We performed a systematic review and meta-analysis to investigate the prevalence of cognitive impairment in adult patients with MMD as well as its clinical and demographic correlates.

METHODS

We performed a systematic search of four electronic databases: PubMed (MEDLINE), EMBASE, Scopus, and Cochrane Library, profiling studies from inception until 7 May 2023. Clinical data consisting of population characteristics, comorbidities, cognitive assessment tools used, and prevalence of cognitive impairment was extracted.

RESULTS

Seventeen studies were included in the meta-analysis, with a total study population of 1,190 patients. All studies assessed cognition, and the overall prevalence of cognitive impairment in MMD patients was 54.59%. A subgroup analysis identified that the prevalence of executive dysfunction in MMD patients was 31.55%. We performed a meta-regression analysis which identified that cognitive impairment was not associated with age, education level, or a history of ischemic or hemorrhagic stroke.

CONCLUSIONS

A substantial proportion of MMD patients have cognitive impairment, and cognitive impairment was found to have no association with a history of stroke. Further research is necessary to investigate the longitudinal relationship of MMD and cognitive impairment, and the impact of bypass surgery on cognitive impairment.

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

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

Fronto-Parietal and White Matter Haemodynamics Predict Cognitive Outcome in Children with Moyamoya Independent of Stroke

Moyamoya disease is a major arteriopathy characterised by progressive steno-occlusion of the arteries of the circle of Willis. Studies in adults with moyamoya suggest an association between abnormal fronto-parietal and white matter regional haemodynamics and cognitive impairments, even in the absence of focal infarction. However, these associations have not been investigated in children with moyamoya. We examined the relationship between regional haemodynamics and ratings of intellectual ability and executive function, using hypercapnic challenge blood oxygen level-dependent magnetic resonance imaging of cerebrovascular reactivity in a consecutive cohort of children with confirmed moyamoya. Thirty children were included in the final analysis (mean age: 12.55 ± 3.03 years, 17 females, 15 idiopathic moyamoya and 15 syndromic moyamoya). Frontal haemodynamics were abnormal in all regardless of stroke history and comorbidity, but occipital lobe haemodynamics were also abnormal in children with syndromic moyamoya. Executive function deficits were noted in both idiopathic and syndromic moyamoya, whereas intellectual ability was impaired in syndromic moyamoya, even in the absence of stroke. Analysis of the relative effect of regional abnormal haemodynamics on cognitive outcomes demonstrated that executive dysfunction was predominantly explained by right parietal and white matter haemodynamics independent of stroke and comorbidity, while posterior circulation haemodynamics predicted intellectual ability. These results suggest that parietal and posterior haemodynamics play a compensatory role in overcoming frontal vulnerability and cognitive impairment.

Differences in Clinical Features among Different Onset Patterns in Moyamoya Disease

Moyamoya disease is characterized by severe stenosis at the ends of the bilateral internal carotid arteries and the development of collateral circulation. The disease is very diverse in terms of age at onset, onset patterns, radiological findings, and genetic phenotypes. The pattern of onset is mainly divided into ischemic and hemorrhagic onsets. Recently, the opportunity to identify asymptomatic moyamoya disease, which sometimes manifests as nonspecific symptoms such as headache and dizziness, through screening with magnetic resonance imaging has been increasing. Various recent reports have investigated the associations between the clinical features of different onset patterns of moyamoya disease and the corresponding imaging characteristics. In this article, we have reviewed the natural history, clinical features, and imaging features of each onset pattern of moyamoya disease.

The disease presentation of Moyamoya angiopathy in Eastern India

INTRODUCTION

Clinical spectrum of Moyamoya angiopathy (MMA) differs across populations with different ethnicity. This study, the largest one done among Indian population was undertaken to assess clinico-radiological profile of MMA patients in eastern India.

METHODS

A single centre cross-sectional study was undertaken among 76 MMA cases. Each patient was evaluated for epidemiological, clinical and radiological characteristics. SPSS 25 was used for statistical analysis. P < 0.05 was taken as statistically significant.

RESULTS

36 (47.4%) were children without gender preponderance. There were female predominance among adults (male:female = 1:2.33). Mean age at onset of first neurological symptoms for children was 4.2 ± 2.0years, followed by 34.9 ± 58.2months of latency with final diagnosis at the mean age of 7.4 ± 3.5years. For adults, mean age of onset of first neurological symptoms was 31.5 ± 12.3years, followed by 14.7 ± 41.7months time gap and diagnosed at the mean age of 33.5 ± 12.5years. There was a statistically significant difference between child and adult regarding the diagnostic latency (p = 0.035). Fixed motor weakness (FMW) was the predominant symptom across the whole disease course. Among children predominant first neurological symptom was fixed motor weakness (FMW) (52.8%), followed by seizures (22.2%). FMW was predominant (55%) first neurological complaint, followed by headache (22.5%) among adults. Seizure was more prevalent among children both as first (p = 0.002) and presenting symptom at the time of diagnosis (p = 0.048). Over the course of the disease seizure was more common among children (p = 0.001), while headache was more common among adults (p = 0.017). Recurrence of symptoms was more common among children (p = 0.059). Infarcts were more common among children (91.7%) than adults (72.5%), while hemorrhage was seen only among adults (25%) (p = 0.004). Isolated cerebral cortex was involved more commonly among children (59.4%) than adults (36.1%), while isolated subcortical involvement was seen only among adults (19.4%) (p = 0.016). Majority of the MMA cases were of Suzuki stage 4 (39.5%) and 5 (27.6%). Brain atrophy was associated with diagnostic latency (p = 0.009).

CONCLUSION

Indian Moyamoya presents similar to disease presentation in Caucasian and Japanese patients. It is a frequently overlooked cause of stroke in young, often with various non-motor presentations, failure to recognize which leads to delay in diagnosis. Radiological burden disproportionate to number of acute vascular events, with subtle neurological manifestations like headache or seizure, often with cognitive decline, should raise suspicion of MMA.

Association of cognitive function with cerebral blood flow in children with moyamoya disease

OBJECTIVE

The cognitive effects of main cerebral artery occlusive lesions are unclear in children with moyamoya disease (MMD). The authors aimed to investigate cognitive function in the presurgical phase of pediatric patients with MMD with no apparent brain lesions.

METHODS

In this prospective, observational, single-center study, 21 children (mean age 10 ± 3.0 years, range 5-14 years) diagnosed with MMD at Hokkaido University Hospital between 2012 and 2018 were enrolled. A cross-sectional evaluation of intellectual ability was performed using the Wechsler Intelligence Scale for Children-Fourth Edition at the initial diagnosis. rCBF was measured using [123I] N-isopropyl p-iodoamphetamine/SPECT. The associations among clinical factors, disease severity, regional cerebral blood flow (rCBF), and intelligence test scores were also examined.

RESULTS

The mean full-scale intelligence quotient (FIQ) was 101.8 ± 12.5 (range 76-125) in children with no apparent brain lesions. A significant difference in the intelligence scale index score was observed, most frequently (42.9%) between working memory index (WMI) and verbal comprehension index (VCI; VCI - WMI > 11 points). Regional CBF was significantly reduced both in the left and right medial frontal cortices (left: 61.3 ± 5.3 ml/100 g/min, right 65.3 ± 5.3 ml/100 g/min; p < 0.001) compared to the cerebellum (77.8 ± 6.8 ml/100 g/min). There was a significant association of rCBF in the left dorsolateral prefrontal cortex (DLPFC) with FIQ (r = 0.46, p = 0.034), perceptual reasoning index (PRI; r = 0.44, p = 0.045), and processing speed index (PSI; r = 0.44, p = 0.045). There was an association between rCBF of the left medial frontal cortex and PSI (r = 0.49, p = 0.026). Age of onset, family history, ischemic symptoms, and angiographic severity were not associated with poor cognitive performance.

CONCLUSIONS

Although average intellectual ability was not reduced in children with MMD, the association of reduced rCBF in the left DLPFC and medial frontal cortex with FIQ, PRI, and PSI suggests mild cognitive dysfunction due to cerebral hypoperfusion.

Cognitive Performance Profile in Pediatric Moyamoya Disease Patients and Its Relationship With Regional Cerebral Blood Perfusion

Object: Moyamoya disease affects the cognitive function of pediatric patients, and compromised cerebral blood flow might be the potential cause. We aimed to explore the specific correlation between cognitive impairment and regional perfusion status in pediatric moyamoya disease patients.

Methods: We prospectively enrolled consecutive pediatric moyamoya disease patients admitted to Beijing Tiantan Hospital from July 2017 to March 2019. Arterial spin-labeling magnetic resonance and the Wechsler Intelligence Scale for Children (the 4th edition) were performed on all participants. The cognitive performance of patients was analyzed, and its correlation to cerebral perfusion status was also investigated in the region of interest-based analysis.

Results: A total of 21 patients met the inclusion criteria (mean aged 11.14 ± 2.82, male: female = 11:10). Six patients (28.6%) showed no cognitive deficits in any index score, while 15 (71.4%) showed cognitive deficits with differing severity. Nine (42.9%) patients showed overall cognitive impairment, and all cognitive index scores except for Verbal Comprehension Index were significantly lower than the mean scores of normative data with corresponding age. Perceptual Reasoning Index (p = 0.019) were statistically lower in patients with radiologically confirmed cerebral infarction. Suzuki stage of the left hemisphere negatively correlated to Full-scale Intelligence Quotient (r = −0.452, p = 0.039). Region of Interest analysis showed that cerebral blood flow of the left temporal lobe independently associated with the Processing Speed Index (β = 0.535, p = 0.041).

Conclusion: Pediatric moyamoya disease patients exhibited different levels of cognitive impairment. Cerebral infarction is related to poorer perceptual reasoning ability. Cerebral blood flow in the left temporal lobe positively correlates with processing speed.

Surgery for Moyamoya Disease in Children

Moyamoya disease is a chronic progressive cerebrovascular occlusive disease of the terminal portion of the internal carotid arteries associated with an acquired abnormal vascular network at the base of the brain, often leading to ischemic or hemorrhagic stroke. Moyamoya disease is a relatively common cause of pediatric stroke with a specific racial and well-identified clinical and imaging phenotype. Moyamoya disease is more prevalent in East Asian countries compared with other geographic regions with a higher incidence of familial cases and clinically more aggressive form. Moyamoya disease is one of the few causes of stroke that is amenable to effective surgical revascularization treatment. There are various surgical options available for revascularization, including the direct, indirect, or combined bypass techniques, each with variable responses. However, due to the heterogeneity of the diseases, different clinical course, geographical variables associated with the disease, and availability of a wide variety of surgical revascularization procedures, optimal selection of a surgical candidate and the surgical technique becomes challenging, particularly in the pediatric population. This brief review presents pertinent literature of clinical options for the diagnosis and surgical treatment of moyamoya disease in children.

Effect of revascularization on cognitive outcomes in intracranial steno-occlusive disease: a systematic review

OBJECTIVESteno-occlusive diseases of the cerebral vasculature have been associated with cognitive decline. The authors performed a systematic review of the existing literature on intracranial steno-occlusive disease, including intracranial atherosclerosis and moyamoya disease (MMD), to determine the extent and quality of evidence for the effect of revascularization on cognitive performance.METHODSA systematic search of PubMed/MEDLINE, the Thomson Reuters Web of Science Core Collection, and the KCI Korean Journal Database was performed to identify randomized controlled trials (RCTs) in the English-language literature and observational studies that compared cognitive outcomes before and after revascularization in patients with steno-occlusive disease of the intracranial vasculature, from which data were extracted and analyzed.RESULTSNine papers were included, consisting of 2 RCTs and 7 observational cohort studies. Results from 2 randomized trials including 142 patients with symptomatic intracranial atherosclerotic steno-occlusion found no additional benefit to revascularization when added to maximal medical therapy. The certainty in the results of these trials was limited by concerns for bias and indirectness. Results from 7 observational trials including 282 patients found some cognitive benefit for revascularization for symptomatic atherosclerotic steno-occlusion and for steno-occlusion related to MMD in children. The certainty of these conclusions was low to very low, due to both inherent limitations in observational studies for inferring causality and concerns for added risk of bias and indirectness in some studies.CONCLUSIONSThe effects of revascularization on cognitive performance in intracranial steno-occlusive disease remain uncertain due to limitations in existing studies. More well-designed randomized trials and observational studies are needed to determine if revascularization can arrest or reverse cognitive decline in these patients.

Cognitive Functions in Children and Adults with Moyamoya Vasculopathy: A Systematic Review and Meta-Analysis

Background and Purpose

Patients with moyamoya vasculopathy (MMV) may experience cognitive impairment, but its reported frequency, severity, and nature vary. In a systematic review and metaanalysis, we aimed to assess the presence, severity, and nature of cognitive impairments in children and adults with MMV.

Methods

We followed the MOOSE guidelines for meta-analysis and systematic reviews of observational studies. We searched Ovid Medline and Embase for studies published between January 1, 1969 and October 4, 2016. Independent reviewers extracted data for mean intelligence quotient (IQ) and standardized z-scores for cognitive tests, and determined percentages of children and adults with cognitive deficits, before and after conservative or surgical treatment. We explored associations between summary measures of study characteristics and cognitive impairments by linear regression analysis.

Results

We included 17 studies (11 studies reporting on 281 children, six on 153 adults). In children, the median percentage with impaired cognition was 30% (range, 13% to 67%); median IQ was 98 (range, 71 to 107). Median z-score was –0.39 for memory, and –0.43 for processing speed. In adults, the median percentage with impaired cognition was 31% (range, 0% to 69%); median IQ was 95 (range, 94 to 99). Median z-scores of cognitive domains were between –0.9 and –0.4, with multiple domains being affected. We could not identify determinants of cognitive impairment.

Conclusions

A large proportion of children and adults with MMV have cognitive impairment, with modest to large deficits across various cognitive domains. Further studies should investigate determinants of cognitive deficits and deterioration, and the influence of revascularization treatment on cognitive functioning.

When and why is surgical revascularization indicated for the treatment of moyamoya syndrome in patients with RASopathies? A systematic review of the literature and a single institute experience

BACKGROUND

Moyamoya disease (MMD) is a cerebrovascular disorder characterized by the progressive occlusion of the supraclinoid internal carotid artery (ICA), resulting in the formation of an abnormal cerebral vascular network. When MMD occurs in association with an underlying medical condition, including some distinctive genetic disorders, it is named moyamoya syndrome (MMS). The discrimination between MMD and MMS has been validated by recent genetic researches and international reviews. Similarly to patients suffering from MMD, patients with MMS generally become symptomatic because of ischemic complications, which lead to hemiparesis, transient ischemic events, seizures, and sensory symptoms. RASopathies are a group of neurodevelopmental disorders that can be associated with MMS.

RESULTS

We retrospectively reviewed 18 RASopathy patients with MMS treated at our institution from 2000 to 2015 (16 neurofibromatosis type 1, 1 Costello syndrome, and 1 Schimmelpenning syndrome). Here, we report clinical data, performed surgical procedures, and clinic-radiological outcome of these patients. Most of them received both indirect revascularization and medical therapy.

CONCLUSIONS

At the moment, there are no univocal recommendations on which of these two treatment strategies is the treatment of choice in patients with RASopathies and MMS. We suggest that patients with a good overall prognosis (primarily depending on the distinctive underlying genetic disorder) and initial cerebrovascular disease could benefit from a prophylactic surgical revascularization, in order to prevent the cognitive impairment due to the progression of the vasculopathy.

Neuropsychological impacts of indirect revascularization for pediatric moyamoya disease

PURPOSE

Moyamoya disease (MMD) commonly leads to neurocognitive impairment. This study was carried out to show that temporal encephaloduroarteriosynangiosis (EDAS) has a positive neuropsychological impact on pediatric MMD patients.

METHODS

Fifty-five participants diagnosed with MMD from 2008 to 2014 were included in this retrospective study. The mean age at the preoperative evaluation was 9.5 years and the mean age at postoperative evaluation was 10.4. The average interval of initial and follow-up test was 10 months. K-WISC-III, Rey-Kim memory test, Children's Color Trails test (CCTT), Wisconsin Card Sorting Test (WCST), and Advanced Test of Attention (ATA) were used to evaluate patient's neurocognitive profile.

RESULTS

In this study, preoperative and postoperative neuropsychological fields were compared. Prior operation, pediatric MMD patients showed 54.2% deficit of inattention but only around 2.5% deficit in verbal memory recall function. There was a significant increase of performance IQ and PO score component of PIQ improved almost 10 scores after surgery. For memorial function, there was an improvement of approximately 10 scores in MQ after the surgery. This study also showed parietal activation following surgical treatment which enhanced the ability to interpret visual materials, to register and to retrieve visual information. Interestingly, despite the parietal cover surgery, there was a significant improvement of performance on WCST and CCTT measuring the prefrontal executive function. Concerning failure to maintain set, no significant postoperative improvements were made. However, simple and selective visual attention on ATA was significantly improved postoperatively.

CONCLUSIONS

The results from neuropsychological field comparison testifies the effectiveness of temporal EDAS in pediatric MMD patients. The surgery not only enhances the blood flow in operative regions, but it also improves the broad cerebral function including frontoparietal domains. Such alteration leads to overall advancement in cognitive function which are impaired due to MMD.

Late Cerebrovascular Events and Social Outcome after Adolescence: Long-term Outcome of Pediatric Moyamoya Disease

In this article, the authors review the literature related to long-term outcome of pediatric moyamoya disease, focusing on late cerebrovascular events and social outcome of pediatric patients once they reach adulthood. Late-onset de novo hemorrhage is rare but more serious than recurrence of ischemic stroke. Long-term follow-up data on Asian populations suggest that the incidence of de novo hemorrhage might increase at age 20 or later, even more than 10 years after bypass surgery. Social adaptation difficulty, possibly related to cognitive impairment caused by frontal ischemia, continues in 10-20% of patients after they reach adulthood, even if no significant disability is present in daily life. A treatment strategy aimed at improving long-term outcome and careful follow-up might be required.

Pial Synangiosis Ameliorates Movement Disorders in the Absence of Prior Stroke in Moyamoya Disease

BACKGROUND

Moyamoya disease is a rare cerebrovascular disease characterized by progressive stenosis of the bilateral distal internal carotid arteries and their proximal branches. Both chorea and dystonia have been reported as the initial presentation of moyamoya disease.

OBJECTIVE

The objective was to define the clinical presentation and describe the disease course following pial synangiosis of 3 patients with dyskinesias.

METHODS

A retrospective chart review of 3 cases of patients presenting with movement disorders and ultimately diagnosed with moyamoya disease was performed.

RESULTS

The authors present a case series of 1 patient with dystonia and 2 patients with chorea, all diagnosed with moyamoya disease. All patients experienced resolution of their movement disorders following pial synangiosis. Magnetic resonance imaging disclosed moyamoya disease-related basal ganglia anomalies in all patients.

CONCLUSIONS

Moyamoya disease is an important and surgically treatable cause of movement disorders.

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.

Early surgical treatment benefits early staged pediatric moyamoya disease--single case report

PURPOSE

Surgical revascularization for pediatric moyamoya disease improves cerebral blood flow (CBF) and consequently may prevent further ischemic events. However, the timing of the treatment is controversial especially for patients with no ischemic symptom and normal CBF. The purpose of this case report is to inform and infer the surgical treatment timing for pediatric moyamoya disease patients.

CASE REPORT

A 10-year-old female patient with unilateral moyamoya disease complaining of only headache as a symptom and whose Suzuki stage was II or in transition to III by angiography and CBF was almost normal was admitted to Tokyo Women's Medical University Hospital. We performed superficial temporal artery-middle cerebral artery (STA-MCA) double anastomoses for the patient because we estimated her headache was derived from low perfusion in the brain. STA-MCA bypass surgery was not only effective for relief of her severe headache but also valid for her cerebral perfusion. Her angiography showed much supply from external carotid artery to intracranial arteries via bypass grafts in 7 months.

CONCLUSION

Our case showed early surgical treatment was beneficial for relief of severe headache even for early staged pediatric moyamoya disease patients by improving perfusion pressure and cerebral circulation.

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.

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.

Cognitive function of patients with adult moyamoya disease

BACKGROUND

Neurocognitive impairment is one of several unsolved social issues faced by patients with moyamoya disease. Although efforts have been made to investigate cognitive function using neuropsychologic tasks, generalizability has been limited. Here, in a preliminary study, we used structured neuropsychologic tasks to establish a standardized neuropsychologic assessment for adult moyamoya patients with and without difficulty in social independence.

METHODS

Ten patients with neuroradiologically confirmed adult moyamoya disease (3 male, 7 female) participated. Half of all subjects did not have difficulty with social independence (group 1) and the others had (group 2). Group differences were evaluated after basic cognitive abilities and frontal lobe function were tested.

RESULTS

Although the mean age of group 1 was substantially higher than that of group 2, disease duration did not differ significantly between groups. Means scores for intelligence functions including all subtests for basic cognitive abilities were higher in group 1 compared with group 2. Scores from only 2 frontal lobe evaluation tasks (Trail Making Test B and Theory of Mind) were significantly different between groups.

CONCLUSIONS

This preliminary study provides a profile of neurocognitive dysfunction in adult patients with moyamoya disease using structured neuropsychologic tasks. A broad range of cognitive functions was disrupted particularly in the patients who had difficulty with social independence. To obtain stronger evidence regarding neurocognitive dysfunction in patients with moyamoya disease, a multicenter prospective study is essential.

Selective neuropsychological impairments and related clinical factors in children with moyamoya disease of the transient ischemic attack type

PURPOSE

Moyamoya disease is characterized by progressive narrowing of bilateral internal carotid arteries. Neuropsychological impairments are suspected due to frequent involvement of the frontotemporal areas. The present study thus aimed to investigate the pattern of neuropsychological function in children diagnosed with moyamoya disease.

METHODS

Thirteen children with moyamoya disease of the transient ischemic attack type received standardized neuropsychological tests that evaluate general intellectual function, verbal comprehension, perceptual organization, working memory, processing speed, episodic memory, category fluency and visuospatial function. Related clinical factors were also analyzed.

RESULTS

The results showed single-domain cognitive impairment in around 15 % of patients and multiple-domain cognitive impairments in 23 % of patients. Selective impairments of episodic memory and processing speed were especially noted in those with younger age of onset and prolonged symptom duration.

CONCLUSIONS

Neuropsychological impairments are not infrequent in children with moyamoya disease despite normal general intellectual functioning. The pattern of cognitive dysfunction is often associated with lesions in frontotemporal areas. Early detection and intervention shall be considered regarding cognitive outcome in pediatric group.

Impact of posterior cerebral artery involvement on long-term clinical and social outcome of pediatric moyamoya disease

OBJECT

In the study of pediatric moyamoya disease, information on long-term social outcomes and risk factors for unfavorable social outcomes remains insufficient. The authors analyzed the long-term results of surgical revascularization for pediatric patients with moyamoya disease to determine whether the involvement of a stenoocclusive lesion in the posterior cerebral artery (PCA), relatively common in pediatric moyamoya disease, represents an underlying predictor for unfavorable social outcomes.

METHODS

Prospectively collected data on 61 consecutive patients with moyamoya disease who had undergone combined bypass surgery were analyzed. Neuroradiological features and other baseline clinical factors were incorporated into univariate and multivariate analyses to determine any association with an unfavorable social outcome, defined as difficulty attending regular school or obtaining regular employment.

RESULTS

Posterior cerebral artery involvement detected by angiography on admission was noted in 22 (36.1%) of the 61 patients. Follow-up data were acquired in 56 patients (91.8%), and the mean follow-up period was 15.8 years. While transient ischemic attacks were eliminated in 52 (92.9%) of these 56 patients after surgery, and late-onset ischemic stroke was observed in only 1 patient during the follow-up period, 10 (17.9%) experienced an unfavorable social outcome. Although younger age at onset, longer duration between onset and surgery, infarction present on preoperative neuroradiological images, and PCA involvement had been identified as risk factors for an unfavorable social outcome in univariate analysis, only infarction present on preoperative images and PCA involvement remained statistically significant after multivariate adjustment.

CONCLUSIONS

Posterior cerebral artery involvement can be considered one of the underlying risk factors for unfavorable social outcome and should be studied further to improve social outcome in pediatric moyamoya disease.

Assessment of cognitive function in adult patients with hemorrhagic moyamoya disease who received no surgical revascularization

BACKGROUND AND PURPOSE

Due to controversial surgical treatment for hemorrhagic moyamoya disease (MMD), a large proportion of these patients chose conservative treatment. The aim of this study was to assess cognitive function in adult patients with hemorrhagic MMD who received no surgical revascularization.

METHODS

Twenty-six adult hemorrhagic MMD patients with only intraventricular hemorrhage (IVH) confirmed by positive computed tomography and magnetic resonance imaging scan, 20 patients with spontaneous IVH whose digital subtraction angiography results were negative, and 30 healthy controls were identified and matched for age, gender, education background and living area. Cognitive function was evaluated by Montreal Cognitive Assessment (MoCA). The non-parametric test was used for comparisons among the three groups.

RESULTS

No patient was confirmed cognitive dysfunction at the initial screening. Twenty-four (92%) cases presented mild cognitive impairment (MCI) after 1 year. All the cases demonstrated MCI after 2 years. The difference between cases and healthy controls was statistically significant at the second screening (P = 0.000) and the third screening (P = 0.000), as was that between cases and patients with spontaneous IVH at the second screening (P = 0.000) and the third screening (P = 0.000). In addition, there were significant decreases in all MoCA subscores (P = 0.000) with special regards to delayed recall, visual space and executive function in cases compared with the other two groups. Moreover, significant differences were found in the subgroups of smoking (P = 0.021) and Suzuki angiographic classification of MMD (P = 0.030).

CONCLUSIONS

Cognitive impairment is a long-term complication for adult hemorrhagic MMD patients who underwent conservative treatment.

Long-term follow-up of surgically treated juvenile patients with Moyamoya disease

OBJECT

Surgical revascularization is considered an effective treatment for juvenile patients with moyamoya disease (MMD). Yet the long-term outcome in surgically treated patients still needs to be clarified. More than 30 years have passed since the authors' department started intensively treating pediatric patients with MMD using indirect anastomosis techniques. In this study the authors surveyed the current status of these patients.

METHODS

Activities of daily living (ADLs) were surveyed and present clinical status was assessed based on the modified Rankin scale (mRS). Cerebrovascular events subsequent to surgical treatment were also recorded.

RESULTS

Since 1979, 208 patients younger than 19 years of age with MMD were surgically treated and followed up for > 3 years. Data were available on 172 patients (83%), who had been followed up for a mean of 14.3 years (range 3-32 years). Activity of daily living outcomes were as follows: 138 patients (80.2%) had mRS scores of 0-2, 29 (16.9%) a score of 3, 1 (0.6%) a score of 4, 1 (0.6%) a score of 5, and 3 (1.7%) a score of 6. Cerebrovascular events occurred 8 or more years after surgery in 6 patients (3.4%), that is, 6 hemorrhages and 3 infarctions. The cumulative risk of late-onset stroke at 10, 20, and 30 years after surgical intervention was 0.8%, 6.3%, and 10.0%, respectively.

CONCLUSIONS

This long-term survey demonstrated that most surgically treated pediatric patients with MMD maintain good ADL outcomes. However, a significant number of new cerebrovascular events occurred more than 10 years after the initial surgery. Additional follow-up will help to identify which events may occur during the adult years of patients treated as children.

Neurocognitive impairment in adults with moyamoya disease without stroke

BACKGROUND

Adults with moyamoya disease (MMD) have been shown to manifest cognitive impairment, but it is unclear whether this is the result of ischemic stroke.

OBJECTIVE

To determine whether adults with MMD but without stroke have cognitive impairment.

METHODS

We performed detailed neuropsychological assessments in 30 adults with angiographically confirmed MMD without magnetic resonance imaging (MRI) evidence of stroke.

RESULTS

Twenty patients (67%) exhibited small T2 hyperintensities in the cerebral subcortical white matter on brain MRI but no evidence of gray matter damage. Significant cognitive impairment, defined as half of test scores ≥ 1 SD below the normal mean, was present in 7 patients (23%). Executive functioning, mental efficiency, and word finding were the ability areas most frequently impaired, whereas memory was relatively intact. Clinically significant emotional distress (depression and/or anxiety) was present in 11 patients (37%). Comparable cognitive findings were also observed in the subset of 10 patients (33%) with completely normal static brain MRI.

CONCLUSION

Cognitive impairment in MMD can occur in the absence of ischemic stroke as manifested on MRI.

Influence of Moyamoya disease on psychopathological abnormality in young males in Korea: analysis of multiphasic personal inventory test

We analyzed the results of a multiphasic personal inventory test to confirm whether Moyamoya disease (MMD) affects the psychopathology in a group of young male Koreans. The authors manually reviewed the results of the Korean military multiphasic personal inventory (KMPI) for the examination of conscripts in Korea from July 2006 to May 2010. The normal volunteers group (N = 200) was composed of those males who do not have any brain disease or brain trauma. The MMD group (N = 37) was composed of those with MMD. There were more abnormal results in the MMD group (32.4 %) than in the normal volunteers group (13.0 %, p < 0.001). Results of the Neurosis Set showed that the anxiety scale, the depression scale and the somatization scale were more increased in the MMD group than that in the normal volunteer group (p = 0.014, 0.002 and 0.006, respectively). Results of the Social Relation Set showed that the aggregation scale was more increased in the MMD group than that in the normal volunteers group (p = 0.017). Young males with MMD may have more tendencies to have abnormal results of a multiphasic personal inventory test as compared to that of normal volunteers, suggesting that MMD may cause psychopathology in young Korean males.

Moyamoya disease: functional and neurocognitive outcomes in the pediatric and adult populations

OBJECT

Moyamoya disease is an occlusive cerebrovascular disorder commonly resulting in neurocognitive impairment. The cognitive outcome parameters commonly affected are intelligence, memory, executive function, and quality of life. In this paper, the authors review the existing literature on cognitive and clinical outcomes in adult and pediatric moyamoya populations separately.

METHODS

A systematic review of the cognitive and clinical outcome literature was performed using the PubMed/MEDLINE database. Outcomes data were contrasted between adult and pediatric populations.

RESULTS

Intelligence is the main cognitive outcome parameter affected in pediatric patients with moyamoya disease, whereas adults most commonly suffer from executive function impairment. Memory has not been studied sufficiently in pediatric patients, and its dysfunction in the adult population remains controversial. Quality of life has not been studied appropriately in either population. Surgical revascularization is the only beneficial treatment option, and a combination of direct and indirect bypass techniques has shown benefit, but the impact on the above-mentioned parameters has not been sufficiently elucidated.

CONCLUSIONS

Moyamoya disease affects the cognition and daily function in pediatric patients to a greater extent than in adult patients. Due to the rarity of the disease, there is a distinct lack of high-level evidence regarding cognitive and clinical outcomes.

Intellectual ability and executive function in pediatric moyamoya vasculopathy

AIM

  Moyamoya vasculopathy is characterized by progressive stenosis of the major arteries of the Circle of Willis, resulting in compromised cerebral blood flow and increased risk of stroke. The objectives of the current study were to examine intellectual and executive functioning of children with moyamoya and to evaluate the impact of moyamoya type, stroke (clinical or silent), vasculopathy laterality, and disease duration on neurocognitive abilities.

METHOD

  Thirty pediatric participants (mean age 10 y 10 mo, SD 4 y; 18 females, 12 males) completed age-appropriate Wechsler Intelligence Scales before any therapeutic revascularization procedures. Reports of executive function were obtained from parents and teachers using the Behavior Rating Index of Executive Function.

RESULTS

  Children with moyamoya scored significantly lower than the test standardization samples on all indices of intelligence and ratings of executive functioning (p<0.001). Patients did not differ by type of moyamoya or history of stroke. Patients with bilateral disease and stroke scored significantly lower than those with unilateral disease on measures of overall intellectual function (p=0.035) and verbal comprehension (p=0.04). Deficits in metacognitive executive functions were also more pronounced in bilateral patients according to teacher ratings.

INTERPRETATION

  Children with moyamoya are at risk for intellectual and executive problems, exacerbated by bilateral disease and clinical stroke history.

Childhood moyamoya disease and moyamoya syndrome: a pictorial review

Moyamoya disease is an uncommon chronic cerebrovasculopathy, characterized by progressive stenosis of the terminal portion of the internal carotid artery and its main branches, in association with the development of compensatory collateral vessels at the base of the brain. The etiology is unknown, and was originally considered exclusive to East Asia, with particular prevalence in Japan. Moyamoya disease is increasingly diagnosed throughout the world, and represents an important cause of childhood stroke in Western countries. In some cases, similar angiographic features are evident in children with other medical conditions, such as sickle cell disease and Down syndrome. In these instances, the term "moyamoya syndrome" is used. Diagnosing the vasculopathy, excluding possible associated conditions, and planning treatment and follow-up imaging comprise important aspects of clinical management. We review the key imaging features of childhood moyamoya disease and syndrome, present examples of its associations, and discuss new neuroradiologic methods that may be useful in management.

Correlation between cognitive impairment and cerebral hemodynamic disturbances on perfusion magnetic resonance imaging in European adults with moyamoya disease

Object

Although cognitive impairment has been reported in adults with moyamoya disease (MMD), its relationship with cerebral hemodynamic disturbances has not been investigated. The aims of the present study were to confirm the presence of dysexecutive cognitive syndrome (DCS) in adults with MMD and to explore the relationship of DCS with frontal lobe perfusion as measured by perfusion MR imaging.

Methods

Cerebral blood volume (CBV) ratio and mean transit time delay were measured in frontal and temporoparietal regions using the cerebellum as a reference region in 10 European adults with MMD. In addition, the authors calculated the cerebrovascular reserve (CVR) using the CBV ratio and the acetazolamide challenge. All patients underwent a standardized neuropsychological assessment test battery. The authors defined DCS as an impairment shown on 3 tests or more of executive function.

Results

The authors found DCS in 6 patients. The frontal CVR was lower in patients with DCS than in patients without DCS (mean ± SD: −13.5 ± 13.2% and 20.3 ± 21.3%; p = 0.019, Mann-Whitney U-test). Other parameters of frontal perfusion and temporoparietal CVR were not correlated with DCS.

Conclusions

The authors' findings suggest that DCS is common in European adults with MMD and may be related to frontal perfusion impairment.

Moyamoya disease: current concepts and future perspectives

Moyamoya disease is an uncommon cerebrovascular disease that is characterised by progressive stenosis of the terminal portion of the internal carotid artery and its main branches. The disease is associated with the development of dilated, fragile collateral vessels at the base of the brain, which are termed moyamoya vessels. The incidence of moyamoya disease is high in east Asia, and familial forms account for about 15% of patients with this disease. Moyamoya disease has several unique clinical features, which include two peaks of age distribution at 5 years and at about 40 years. Most paediatric patients have ischaemic attacks, whereas adult patients can have ischaemic attacks, intracranial bleeding, or both. Extracranial-intracranial arterial bypass, including anastomosis of the superficial temporal artery to the middle cerebral artery and indirect bypass, can help prevent further ischaemic attacks, although the beneficial effect on haemorrhagic stroke is still not clear. In this Review, we summarise the epidemiology, aetiology, clinical features, diagnosis, surgical treatment, and outcomes of moyamoya disease. Recent updates and future perspectives for moyamoya disease will also be discussed.

Sudden cortical blindness in an adult with moyamoya disease

BACKGROUND

We report a case of an adult with MMD who presented initially with left visual field defect that had suddenly progressed to bilateral cortical blindness 1 year and 9 months later.

CASE DESCRIPTION

A 33-year-old male presented with visual blurring and mild right hemiparesis that developed suddenly. He was regarded as having MMD based on an imaging study. An inverted encephalodurogaleosynangiosis using the left occipital artery and inverted encephaloduroarteriogaleosynangiosis with the parietal branch of the superficial temporal artery were done. The postoperative course was uneventful and without any complication. Several months later, he visited again because of sudden bilateral blindness preceded by repeated transient blindness in both eyes for 4 days. The right posterior temporal artery, which was well visualized at the time of the first postoperative follow-up angiography, was no longer seen on repeated 4-vessel angiography. Biochemical analysis including prothrombin and thrombin time, activated partial thromboplastin time, fibrinogen, d-dimer, plasminogen, antithrombin, platelet, protein C and S, lupus anticoagulant, and cardiolipin antibodies; VDRL was within the reference range.

CONCLUSION

The authors suggest abnormal thromboembolism as a presumed mechanism of the pathogenesis of MMD in this patient.

Hypomelanosis of Ito and Moyamoya disease

Moyamoya disease is a cerebrovascular disease characterized by stenosis and occlusion of the arteries of the circle of Willis, with abnormal telangiectatic collateral circulation at the base of the brain. An association between moyamoya disease and neurofibromatosis 1, a neurocutanoeus disorder, is well established in the literature. However, its association with other neurocutaneous syndromes is infrequently reported. Hypomelanosis of Ito, another neurocutaneous syndrome, is characterized by macular hypopigmented skin whorls and variable neurologic involvement. Only one case study of an association between hypomelanosis of Ito and moyamoya disease has been reported in the English literature. We report a 17-year-old girl with both hypomelanosis of Ito and angiographic moyamoya disease. She presented with intractable seizures, progressive left hemiparesis, and skin manifestations of hypomelanosis of Ito. Although one might consider a coincidental association, this second case points to an association between the two disorders. Detailed neuroimaging, in particular angiography, should be considered in children with hypomelanosis of Ito and abnormal neurologic findings.

Prediction of the clinical outcome of pediatric moyamoya disease with postoperative basal/acetazolamide stress brain perfusion SPECT after revascularization surgery

BACKGROUND AND PURPOSE

We evaluated whether basal/acetazolamide stress brain perfusion SPECT performed after revascularization surgery can predict the further clinical outcome of patients with pediatric moyamoya disease.

METHODS

A total of 77 (31 males, 46 females, age 6.6+/-3.2 years) patients with postoperative pediatric moyamoya disease who underwent basal/acetazolamide stress brain perfusion SPECT 6 to 12 months after revascularization surgery and who were followed-up >12 months after SPECT were included. Mean follow-up period after SPECT was 36+/-19 months. Sixty-two patients underwent bilateral ribbon encephaloduroarteriosynangiosis (EDAS), 14 bilateral EDAS, and 1 unilateral EDAS. Ordinal logistic regression analysis using 5 independent variables (infarction on preoperative MRI, age at the first operation, highest Suzuki stage on cerebral angiography, and regional cerebrovascular reserve on postoperative SPECT) against postoperative clinical outcomes was performed.

RESULTS

Fifty-one patients had preserved reserve on postoperative SPECT and their clinical outcomes were excellent (30), good (15), fair (4), and poor (2); 26 patients had decreased reserve (excellent, 1; good, 7; fair, 14; poor, 4). On ordinal logistic regression analysis, age at the first operation (P=0.033) and reserve on postoperative SPECT (P<0.001) were statistically significant.

CONCLUSIONS

Basal/acetazolamide stress brain perfusion SPECT performed at 6 to 12 months after the indirect bypass operation could predict the further clinical outcome of pediatric patients with moyamoya disease. Patients with decreased cerebrovascular reserve will have remaining neurological deficit and ischemic attacks on follow-up.

Die Moyamoya-Erkrankung

Moyamoya disease is an idiopathic progressive vasculopathy characterized by slowly progressive narrowing involving the distal internal carotid artery and the proximal circle of Willis. Collateral vessels develop to compensate for the slowly progressive stenosis. These enlarged collaterals appear as a "puff of smoke" on angiography, which gives the disease its name. This review discusses the clinical manifestation, imaging findings, and angiographic features.

Revascularisation surgery for paediatric moyamoya: a review of the literature

INTRODUCTION AND AIMS

The role of and optimal surgical revascularisation technique for paediatric moyamoya syndrome (MMS) are controversial. In this literature review our primary aim was to evaluate the evidence base for the efficacy of surgical revascularisation for the treatment of paediatric MMS. Secondary aims were to estimate the rate of peri-operative complications and to ascertain whether direct or indirect revascularisation techniques resulted in differences in clinical or radiological outcomes.

METHODS

Papers describing surgical revascularisation and its outcome in the treatment of children with MMS were identified from the OVID Medline database (1966-2004). Only papers in English were reviewed. Data were abstracted using a standardised form.

RESULTS

Fifty-seven studies, including data on 1,448 patients, were reviewed. Most were Japanese; 10% were from Western institutions. Indications for revascularisation were described in <15% of studies and varied between centres. Indirect procedures were most commonly performed (alone in 73% of cases, combined with direct procedures in 23%). The rates of peri-operative stroke and reversible ischaemic events were 4.4 and 6.1% respectively. Out of 1,156 (87%) patients, 1,003 derived symptomatic benefit from surgical revascularisation (complete disappearance or reduction in symptomatic cerebral ischaemia), with no significant difference between the indirect and direct/combined groups. Data on developmental and functional outcomes were limited and of uncertain significance as they were not related to pre-operative status. Good collateral formation was significantly more frequent in the direct/combined group than in the indirect group (chi(2), p<0.001).

CONCLUSIONS

Data from the medical literature suggest that surgical revascularisation is a safe intervention for paediatric MMS and most treated patients derive some symptomatic benefit. However, paucity of data on selection criteria and more global outcome measures means that the impact of surgical revascularisation on natural history remains uncertain. Direct and/or combined procedures provide better revascularisation, but this is not associated with differences in symptomatic outcome. International standardisation of the clinical approach to the treatment of paediatric MMS is urgently needed to critically evaluate the optimal indications for and timing of surgical revascularisation.

Arterio-embolic ischemic stroke in children with moyamoya disease

INTRODUCTION

Moyamoya (MM) disease is a rare steno-occlusive cerebrovascular disease known to occur in children and adults. The most serious complications in children are developmental delay and mental retardation due to recurrent hemodynamic stroke.

CASES

We report two pediatric patients without coagulopathy who suffered from severe arterio-embolic ischemic complications despite antiplatelet medication.

DISCUSSION

These observations underline the potential impact of cerebral thromboembolism on the pathophysiology of the stroke and thus on the treatment of children with MM disease.

Moyamoya disease presented with migrainelike headache in a 4-year-old girl

A 4-year-old girl was admitted to our department with the complaints of severe headache, nausea, vomiting, and photophobia. She had a 1-year history of migrainelike headache that occurred every 1 to 2 months. Her neurologic examination was normal, but T-weighted axial magnetic resonance imaging (MRI) of the brain showed flow void within the basal ganglia owing to parenchymal vascular collaterals. Magnetic resonance angiography and digital substraction carotid angiography showed both occlusion of the internal carotid artery in the supraclinoid portion and extensive parenchymal vascular collaterals. Because there was no evidence of risk factors for cerebral arterial occlusion and cerebral infarct or hemorrhage, she was diagnosed as having moyamoya disease. In any case of atypical migrainelike headache, a detailed investigation should be kept in mind to detect an underlying vascular disease such as moyamoya.

Familial moyamoya disease in Caucasians

There are few reports of moyamoya disease (MMD) in the Caucasian population and even fewer descriptions of the natural history of the disease. The study reports a 12-year follow-up of two white male siblings with MMD. Although both brothers had a persistently abnormal electroencephalogram and a learning disorder, the siblings recovered on aspirin and antiepileptic therapy with minimal neurologic residua. The occurrence of MMD in these siblings contributes to the evidence that MMD has a hereditary basis in Caucasians, as well as the Japanese. Even with the use of conservative measures, children may still have persistent yet minor cerebrovascular insults. In addition to the two patients discussed, this study reviewed the literature on all cases of MMD reported within families. Future follow-up studies are required to determine the natural history and the appropriate medical and surgical management of MMD.