Moyamoya: Indiana University Medical Center experience

Timing of Revascularization in Ischemic Moyamoya Disease: Association of Early Versus Delayed Surgery with Perioperative and Long-Term Outcomes

OBJECTIVE

Patients with nmoyamoya disease (MMD) who present primarily with ischemic stroke are known to have greater rates of perioperative strokes as compared with those who present with nonstroke symptoms. The optimal timing for revascularization for these patients remains unclear.

METHODS

From 1994 to 2015, 91 patients with MMD presented with signs and symptoms of an acute ischemic stroke with diffusion restriction correlate on magnetic resonance imaging, and these patients were subdivided into those who underwent early revascularization (<90 days from last stroke), versus those who underwent delayed revascularization (≥90 days after last stroke), based on evidence that most neurological recovery after stroke occurs during the first three months. Perioperative and long-term outcomes were compared between the 2 surgical cohorts.

RESULTS

In total, 27 patients underwent early revascularization, and 64 patients underwent delayed revascularization. Patients who underwent early revascularization had a statistically greater rate of perioperative stroke (P = 0.04) and perioperative mortality (P = 0.03), and overall complication rate (P = 0.049). At last follow-up of 5.2 ± 4.3 years, patients who underwent delayed revascularization had a lower mortality rate (P = 0.01) and a lower overall postoperative stroke incidence (P = 0.002). As a function of time, patients with MMD undergoing delayed revascularization had a statistically higher length of stroke-free survival (P = 0.005).

CONCLUSIONS

Patients with MMD who present with ischemic stroke are more likely to have perioperative strokes, overall perioperative complications, worse long-term mortality rates, and lower rates of stroke-free survival if revascularization surgery occurred within 90 days of last stroke.

Surgical revascularization for pediatric moyamoya: the role of surgical mentorship in sustaining and developing a neurovascular service

OBJECTIVE

Obtaining operative experience for the treatment of rare conditions in children represents a challenge for pediatric neurosurgeons. Starting in November 2017, a surgeon was mentored in surgical revascularization (SR) for pediatric moyamoya with a view to service development and sustainability. The aim of this audit was to evaluate early outcomes of SR for pediatric moyamoya during and following a surgical mentorship.

METHODS

A retrospective cohort study with chart/database review of consecutive moyamoya surgeries performed by a new attending surgeon (between November 2017 and March 2020) was compared to a previously published cohort from the authors' institution in terms of clinical and angiographic outcomes, complications, operating time, and length of stay. A standardized technique of encephaloduroarteriomyosynangiosis with the superficial temporal artery was used.

RESULTS

Twenty-two children underwent 36 indirect SRs during the study period. Patient demographics were similar between cohorts. The first group of 6 patients had 11 SRs performed jointly by the new attending surgeon mentored by an established senior surgeon (group A), followed by 10 patients with 16 SRs performed independently by the new attending surgeon (group B). The last 6 patients had 9 SRs with the new attending surgeon mentoring a senior fellow (group C) in performing SR. Good angiographic collateralization (Matsushima grades A and B) was observed in 80% of patients, with similar proportions across all 3 groups. A total of 18/19 symptomatic patients (95%) derived symptomatic benefit. There was no perioperative death and, compared to the historical cohort, a similar proportion had a recurrent arterial ischemic event (i.e., acute ischemic stroke) necessitating a second SR (1/22 vs 3/73). Operative times were longest in group C, with no difference in length of hospital stay among the 3 groups.

CONCLUSIONS

Early outcomes demonstrate the feasibility of mentorship for safely incorporating new neurosurgeons in sustaining and developing a tertiary-level surgical service.

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.

Racial phenotypes in moyamoya disease: a comparative analysis of clinical presentation and natural history in a single multiethnic cohort of 250 hemispheres

OBJECTIVE

The authors aimed to determine whether differences exist in presentation and natural history when comparing Asian patients with moyamoya disease (MMD) to those of other ethnicities in North America.

METHODS

A database of 137 patients with MMD presenting to their institution between 1994 and 2015 was reviewed. Baseline characteristics and outcome variables, including stroke and functional outcome, were compared between Asian and non-Asian patients. Unadjusted Kaplan-Meier survival analysis and adjusted Cox regression models were used to compare stroke-free survival and stroke hazard after diagnosis among hemispheres of both racial groups. The analysis was stratified by age group, and censoring was performed until last follow-up or at the time of surgery. Because the relative rate of stroke changed between Asian and non-Asian adults after 1.5 years of follow-up, a time-segmented analysis focusing on the period 1.5 years after diagnosis was performed.

RESULTS

The cohort comprised 23% (31/137) Asian and 77% (106/137) non-Asian patients with MMD with a bimodal age distribution. Non-Asian patients had a higher prevalence of increased BMI (p = 0.02) and smoking (p = 0.04). Among patients who presented with stroke (n = 90), hemorrhage was significantly more common among Asians (p = 0.02). The natural history analysis included 250 hemispheres: 67 pediatric and 183 adult hemispheres. The overall mean follow-up duration since diagnosis was 3.3 years. Among adults, Asian patients had a higher incidence of stroke (8.0 per 100 person-years vs 3.0 per 100 person-years) over a mean follow-up of 3.3 years, but results were not statistically significant (p = 0.45). In the period beginning 1.5 years after diagnosis, Asian adults had a significantly higher hazard of stroke over a mean follow-up of 7.7 years, while controlling for sex, hypertension, and stroke before diagnosis (hazard ratio 8.8, p = 0.02). Among pediatric patients, Asians also had a higher stroke incidence (10.0 per 100 person-years vs 3.5 per 100 person-years) over a mean follow-up of 3.2 years; however, results did not reach statistical significance (p = 0.40). Functional outcome was similar between both ethnic groups at last follow-up (p = 0.57).

CONCLUSIONS

This study suggests a comparatively more progressive course of MMD in Asians. Further studies are required to fully characterize the phenotypic distinctions between different races and underlying pathophysiological mechanisms.

Imaging of Non-atherosclerotic Vasculopathies

Non-atherosclerotic vasculopathies (NAVs) may present with various neurological symptoms ranging from headache, stroke, visual symptoms, and various types of intracranial hemorrhage. NAVs result from different etiologies which include collagenopathies, immunological, hematological, and infection mechanisms, and other rarer unidentifiable or idiopathic causes. NAV etiologies account for about 10–15% and 20–25% of adult and pediatric stroke cases, respectively, and therefore, diagnosing the underlying cause of NAV becomes clinically very important. Clinical diagnosis of NAV is challenging because the clinical presentation is very non-specific and overlapping with various other central nervous system disorders. Before the advent of non-invasive techniques, making a diagnosis of non-atherosclerotic vasculopathy as a cause of the stroke was very challenging. Today with newer techniques such as high-resolution magnetic resonance (MR), MR and computed tomography perfusion, and angiogram, there are number of pointers which can give us a lead about the non-atherosclerotic causes. Imaging may provide the first lead to the clinician regarding the diagnosis or possible differential diagnosis so that the targeted and focused biomarkers (blood, cerebrospinal fluid, or/and in some cases biopsies) may be obtained to clinch the diagnoses. The purpose of the article is to enumerate the causes, clinical features, and illustrate the imaging findings of the various non-atherosclerotic vasculopathic disorders and discuss “pearls” to their diagnosis. In this article, we have also discussed the latest advances in vascular imaging and elaborated on few uncommon non-atherosclerotic vasculopathies. These are very relevant clinically in the day-to-day practice for the radiologist, neurologist, and the neurointerventionalist.

Functional Outcomes After Revascularization Procedures in Patients With Hemorrhagic Moyamoya Disease

BACKGROUND

Poor natural history of hemorrhagic Moyamoya disease (MMD) is related to high rehemorrhage rates between 32% and 61%. Postrevascularization, rehemorrhage rates reportedly decrease to 12% to 17%.

OBJECTIVE

To evaluate long-term functional outcomes and rehemorrhage rates of hemorrhagic MMD patients treated with surgical revascularization and examine these in relation to clinical and radiological factors.

METHODS

Patients treated surgically for hemorrhagic MMD over a 26-yr period were identified. Modified Rankin scale (mRS) was used to assess clinical status at presentation and functional outcomes. Multivariable regression analyses were performed to evaluate the risk factors associated with rehemorrhage rates and functional outcomes.

RESULTS

A total of 104 patients (mean age: 38.04 yr) were identified. The mean mRS score at baseline was 1.3. Of 172 revascularized hemispheres, 157 (91.3%) were direct superficial temporal artery (STA)-middle cerebral artery (MCA) bypasses and the rest indirect. Over the mean follow-up of 61.4 mo, 8 of 104 patients (7.7%) experienced rehemorrhage with rehemorrhage rate per person-years of 1.9%. A total of 4 patients died with 1 related to rehemorrhage. At the last follow-up, mean mRS score improved to 1.1. No significant risk factors were identified in relation to the rehemorrhage rates (P < .05). The patients' initial mRS score was positively associated with mRS scores at the final follow-up (P < .001). STA-MCA direct bypass was associated with better performance status (P = .033).

CONCLUSION

Rehemorrhage rate following surgical revascularization of the hemorrhagic MMD patients at 7.7% is lower compared with much higher natural history rates. Surgical revascularization improved patients' performance status. These outcomes support performing revascularization procedure with a preference for direct STA-MCA bypasses.

Postpartum-Onset Moyamoya Disease: A Rare Cause of Stroke in Unexpected

Moyamoya disease (MMD) is a chronic cerebrovascular occlusive disease that is characterized by progressive bilateral stenosis of the terminal portion of the internal carotid artery and its main branches. Cerebrovascular events are the primary presenting symptoms and are related both to stenosis and occlusion of the ICAs and their main branches. Detection of bilateral stenosis by cerebral angiography is considered the gold standard, but computed tomography angiography (CTA) is also an acceptable method of diagnosis. In the current literature, there are no precise data on the incidence of moyamoya disease in Europe and the United States. Also, the pathogenesis of MMD remains obscure, and genetic factors and inflammation are the two most representative mechanisms. Here, we report the case of MMD in a 29-year-old African American female who presented with an ischemic stroke for the second time that manifested after pregnancy. This case is important to increase awareness of the probability of this rare disease in Western countries as well as to call attention to pregnancy's accelerating effects of MMD. Careful, long-term neurologic and radiologic follow-up is essential in adult patients with MMD to prevent additional stroke events and improve outcomes.

Moyamoya Disease in a Middle-Aged Hispanic Woman: A Case Illustration

Moyamoya disease is a rare cerebrovascular disease of unknown etiology, once known to be rare in the United States as compared to East-Asian countries, it is now an increasingly recognized cause of strokes in the United States, as the prevalence of the disease appears to be increasing. We describe a case of a 41-year-old Hispanic female patient presenting to our hospital with a stroke. She had two episodes of right arm weakness and clumsiness prior to presentation to the hospital that had resolved upon arrival. Despite a CT head negative for stroke, further imaging work-up was performed including MRI of the brain with magnetic resonance angiography (MRA) and conventional angiogram, which showed characteristic imaging findings leading to the diagnosis of Moyamoya disease. The patient subsequently underwent elective surgical intervention with Encephaloduroarteriosynangiosis (EDAS) procedure to prevent further complications.

Differing Surgical Outcomes in a Multiethnic Cohort Suggest Racial Phenotypes in Moyamoya Disease

BACKGROUND

Variable Moyamoya disease (MMD) genotypes and phenotypes between different races have been suggested previously. This study investigates differences in surgical complications and response to revascularization among Asian patients with MMD compared with other ethnicities in North America.

METHODS

From a database of 185 patients with moyamoya presenting to our institution between 1994 and 2015, 85 patients with MMD underwent surgery and constituted the study cohort. Baseline characteristics before surgery, procedure-related complications, length of hospital stay, and outcome variables including stroke and functional outcome were compared between Asian and non-Asian patients. Kaplan-Meier survival analyses were used to compare time to ipsilateral stroke and any cerebrovascular event after bypass.

RESULTS

Our surgical cohort consisted of 27% (23/85) Asian and 73% (62/85) non-Asian patients with MMD with a bimodal age distribution. Among the subset of patients who presented with stroke (n = 55), hemorrhage was significantly more common among Asian patients (P = 0.007). In 120 revascularization procedures, per-operative complication rates were greater among Asian patients while controlling for age, type of surgery, and stroke history (odds ratio 2.94; 95% confidence interval 1.16-7.48; P = 0.02). The mean follow-up time after surgery was 4.57 years. Ipsilateral cerebrovascular event rates were 4.77 per 100 person-years in non-Asian patients and 6.51 per 100 person-years in Asians (P = 0.66). Unfavorable modified Rankin Scale scores (>2) were found in 22% of Asian patients and 8% of non-Asian patients on last follow-up (P = 0.13).

CONCLUSIONS

Asian patients with MMD may be more susceptible to surgical complications and may differ from other races in their response to revascularization. Further long-term prospective studies are needed to investigate these findings.

Other cerebrovascular occlusive disease

In this chapter we review the optimal imaging modalities for subacute and chronic stroke. We discuss the utility of computed tomography (CT) and multimodal CT imaging. Further, we analyze the importance of specific magnetic resonance imaging sequences, such as diffusion-weighted imaging for acute ischemic stroke, T2/fluid-attenuated inversion recovery for subacute and chronic stroke, and susceptibility imaging for detection of intracranial hemorrhages. Different ischemic stroke mechanisms are reviewed, and how these imaging modalities may aid in the determination of such. Further, we analyze how topographic patterns in ischemic stroke may provide important clues to the diagnosis, in addition to the temporal evolution of the stroke. Lastly, specific cerebrovascular occlusive diseases are reviewed, with emphasis on the optimal imaging modalities and their findings in each condition.

Etiology and pathogenesis of Moyamoya Disease: An update on disease prevalence

Moyamoya disease is a chronic cerebrovascular occlusive disease that is characterized by progressive stenosis of the terminal portion of the internal carotid artery and its main branches. The occurrence of Moyamoya disease is related to immune, genetic, and other factors. Though the research of Moyamoya disease has made great strides in the past 60 years, the etiology and pathogenesis are largely unknown. This review will focus on the genetic pathogenic and inflammation factors of Moyamoya disease.

National Analysis of 2454 Pediatric Moyamoya Admissions and the Effect of Hospital Volume on Outcomes

BACKGROUND AND PURPOSE

Comprehensive multicenter data on treatment of pediatric moyamoya in the United States is lacking. We sought to identify national trends in the diagnosis and treatment of this disease.

METHODS

A total of 2454 moyamoya admissions from 1997 to 2012 were identified from the Kids Inpatient Database. Demographics, inpatient costs, interventions, and discharge status were analyzed. Admissions with and without surgical revascularization were reviewed separately. The effect of hospital moyamoya volume on outcomes was analyzed by multivariate regression analysis.

RESULTS

Care of moyamoya patients has been concentrating at high-volume centers during the past 12 years. Among moyamoya admission without surgical revascularization, high-volume hospitals show no difference in length of stay, cost, or complications compared with low-volume centers. However, low-volume hospitals have more nonroutine discharges (odds ratio, 2.32; P=0.0005) and inpatient deaths (odds ratio, 12.7; P=0.02) when no revascularization was performed. In contrast, among admissions with surgical revascularization, high-volume centers had decreased length of stay (4.7 versus 6.2 days; P=0.004), reduced cost ($88 000 versus $138 000; P<0.0001), and no increase in complications (P=0.29) compared with low-volume centers. Admissions with revascularization to low-volume hospitals also had increased likelihood of nonroutine discharge (odds ratio, 8.23; P=0.02) compared with high-volume centers.

CONCLUSIONS

This is the largest study of US pediatric moyamoya admissions to date. These data demonstrate that volume correlates with outcome, indicating high-volume centers provide significantly improved care and reduced mortality in pediatric moyamoya patients, with the most marked benefit observed in admissions for surgical revascularization.

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.

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.

The GC + CC genotype at position -418 in TIMP-2 promoter and the -1575GA/-1306CC genotype in MMP-2 is genetic predisposing factors for prevalence of moyamoya disease

BACKGROUND

To investigate the association of single-nucleotide polymorphisms (SNPs) in matrix metalloproteinases (MMPs)-2, -3, and -9 and tissue inhibitor of metalloproteinase (TIMP)-2 with moyamoya disease (MMD). We conducted a case-control study of MMD patients by assessing the prevalence of six SNPs of MMP-2 -1575G > A [rs243866], MMP-2 -1306C > T [rs243865], MMP-3 -1171 5a/6a [rs3025058], MMP-9 -1562C > T [rs3918242], MMP-9 Q279R [rs17576], and TIMP-2 -418G > C [rs8179090].

METHODS

Korean patients with MMD (n = 107, mean age, 20.9 ± 15.9 years; 66.4% female) and 243 healthy control subjects (mean age, 23.0 ± 16.1 years; 56.8% female) were included. The subjects were divided into pediatric and adult groups. The genotyping of six well-known SNPs (MMP-2 -1575G > A, MMP-2 -1306C > T, MMP-3 -1171 5a/6a, MMP-9 -1562C > T, MMP-9 Q279R, and TIMP-2 -418G > C) in MMP and TIMP genes was performed by polymerase chain reaction-restriction fragment length polymorphism assays.

RESULTS

A significantly higher frequency of the GC genotype for TIMP-2 -418 G > C was found in MMD patients. The MMP-9 Q279R GA + AA genotype showed a protective effect for MMD. The GA/CC MMP-2 -1575/-1306 genotype was significantly more prevalent in MMD patients.

CONCLUSIONS

Our findings demonstrate that TIMP-2 -418 GC + CC and MMP-2 -1575GA/-1306CC genotypes could be genetic predisposing factors for MMD development.

Adult moyamoya disease in an urban center in the United States is associated with a high burden of watershed ischemia

BACKGROUND

Adult moyamoya disease is rare in the United States, and patients mostly present with cerebral ischemia. However, clinical and neurodiagnostic correlates of ischemia are not well known in this population. We sought to characterize the clinical and radiographic features of moyamoya disease in a large urban center in the United States, with a focus on angiographic and neuroimaging patterns of ischemia.

METHODS AND RESULTS

We retrospectively reviewed charts of consecutive adult moyamoya disease patients evaluated at 2 centers in Houston, Texas from January 2002 to December 2011. We reviewed all available cerebral angiograms and neuroimaging studies to evaluate the Suzuki grades, presence of intracranial hemorrhage or ischemia, infarct patterns, and vascular territory distribution. Our analysis was mainly descriptive. We identified 31 adults with moyamoya disease who met our inclusion criteria. The female-to-male ratio was 2.4:1. The majority of patients were white, followed by Hispanic, black, and Asian. Most presented with ischemia (61%), followed by headaches, and intracranial hemorrhage. Of the 22 patients with available neuroimaging, 72.7% had ischemic findings, with the vast majority having a watershed pattern (81.3%).

CONCLUSIONS

We observed a high burden of ischemia, mostly watershed pattern on neuroimaging in our adult moyamoya disease patients. Long-term monitoring of adult moyamoya disease patients in the United States would be useful to better understand the natural history of this condition.

Moyamoya in Hispanics: not Only in Japanese

Moyamoya disease was first described in 1957 as hypoplasia of the bilateral internal carotid arteries, the characteristic appearance of the associated network of abnormally dilated collateral vessels on angiography was later likened to something hazy, like a puff of cigarette smoke, which, in Japanese, is moyamoya. This paper describes two cases of moyamoya presentations, including moyamoya disease and moyamoya syndrome. Moyamoya may rarely occur in North American Hispanic patients. The presentation can vary significantly and ranges bwtween fulminant outcome and prolonged survival. Awareness about moyamoya and its different presentations may be beneficial for the patients and can improve the outcome.

A case with unusual stroke and fulminant outcome in a Hispanic male

Patient: Male, 42

Final Diagnosis: Moyamoya disease (MMD)

Symptoms: Aphasia • concentration difficulty • dysarthria • personality change

Medication: —

Clinical Procedure: —

Specialty: Radiology

Moyamoya disease: a case of vanishing cerebral vessels

PURPOSE

To provide an overview of moyamoya disease (MMD) including pathophysiology, epidemiology, clinical presentation, diagnosis, treatment, and prognosis.

DATA SOURCES

Selected clinical and epidemiological studies, review articles, and diagnostic guidelines for MMD.

CONCLUSIONS

MMD is a rare cerebrovascular disease characterized by progressive stenosis of the distal internal carotid arteries and their major branches. The dilated and fragile basal collateral circulations display a "puff of smoke" appearance and thus are called moyamoya vessels. Other unique features of MMD include 2:1 female preponderance and its peak incidence in two age groups: early childhood and adults in their mid-40s. The pathophysiology of MMD is unclear and possible causes include genetic linkage, angiogenesis, autoimmune disease, cranial radiation, and infection of the head and neck. Most patients are symptomatic and may present with ischemic or hemorrhagic strokes, seizure, or headache. The diagnosis depends on clinical presentation and radiographic imaging, and disease progression may be halted with direct or indirect cerebral revascularization.

IMPLICATIONS FOR PRACTICE

It is important to make a correct diagnosis and provide appropriate treatment to reduce the morbidity and mortality associated with MMD. A prompt referral for possible surgical revascularization offers the best chance to reduce additional cerebral injuries and improve clinical outcomes.

CRAO in Moyamoya Disease

Moyo Moya Disease (MMD) is a rare, progressively stenotic condition of the intracranial arteries with various cerebrovascular manifestations. Ocular manifestations are seen very rarely and there are only few case reports of ocular perfusion anomalies. Central Retinal Artery Occlusion (CRAO) can be caused by atherosclerosis related thrombosis, carotid embolism, cardiac embolism, thrombophilic disorders, giant cell arteritis, etc. We are reporting a 26 years old patient with CRAO in the right eye, who was found to have the typical features of MMD on cerebral angiography. CRAO with MMD is a rare occurrence.

Surgical revascularisation for childhood moyamoya

PURPOSE

Children with moyamoya disease/syndrome (MM) have a high rate of recurrent arterial ischaemic stroke (AIS) and associated neurological morbidity; surgical revascularisation (SR) has the potential to prevent this. Here we describe our experience of SR for childhood mm.

METHODS

This study is a retrospective review of case notes and radiology of children with moyamoya who underwent SR at our centre.

RESULTS

Seventy-three children with MM and who had SR were identified, with median age at presentation of 4.75 years (range 0.6-14.5). Children with >1 AIS or transient ischaemic attack (TIA) and who had not infarcted the whole territory of the diseased carotid artery were offered SR, with the primary aim of preventing further AIS. One hundred and thirty-four SR procedures were undertaken: 82 indirect (62.4 %) and 49 (37.6 %) direct procedures with 3 second SR procedures following initial SR. Median age at surgery was 7.3 (1-18.2) years. There was no perioperative mortality. One anticoagulated child developed an intracranial haemorrhage on the fifth post-operative day. Median duration of follow-up was 34 (5-166) months. Three children (4.1 %) had recurrent AIS (one silent) after SR; two with sickle cell disease had intracranial haemorrhage 1.5 and 11 months post-SR. TIAs improved in 42 out of 53 (79.2 %).

CONCLUSION

Our experience of SR for paediatric MM is comparable to other large series. SR is safe, and the rate of recurrent AIS after SR is lower than would be anticipated, on the basis of known natural history of MM. There was no observed difference in outcome of recurrent AIS for direct versus indirect procedures in this series.

Characterization of inpatient moyamoya in the United States: 1988-2004

Background and Purpose: Moyamoya disease has been classically described by the Asian experience, yet clinical aspects of moyamoya phenomena in the United States remain vastly undefined. The multifocal occlusive arterial disorder may be linked with numerous conditions; however, later stages of this syndrome share common vascular pathophysiology. This study is aimed at characterizing inpatient moyamoya cases in the United States over a broad time span. Methods: A comprehensive analysis of the Nationwide Inpatient Sample of the Healthcare Cost and Utilization Project (Releases 1–13, 1988–2004) based on ICD-9-CM code 437.5 was performed. Annual percentages and trends analyses were conducted for demographic variables, admission characteristics, co-morbidities, and procedures. Result: 2247 admissions of moyamoya cases were analyzed from a wide geographic distribution throughout the United States between 1988 and 2004. Age at admission varied considerably (mean 29.6 ± 18.5 years), affecting women more frequently than men (61.9%). Various racial groups were identified (35.4% White, 19.7% African American, 5.6% Hispanic, 8.3% Asian or Pacific Islander, 1.4% Native American). Admissions were typically emergent (38.8%) or urgent (18.7%), although elective admissions occurred (24.4%). Aside from moyamoya, sickle cell disease was diagnosed in 13.6%, ischemic stroke in 20.7%, intracerebral hemorrhage in 7.4%, transient ischemic attack in 3.4%, and subarachnoid hemorrhage in 3.1%. Cerebral angiography was performed in 24.9% while extracranial–intracranial bypass was done in 8.4% of patients. Conclusion: Moyamoya in the United States is a heterogeneous condition affecting individuals of all ages across a diverse racial spectrum and wide geographic distribution. Further recognition of moyamoya syndrome may facilitate ongoing research and future therapeutic approaches.

Electroencephalogram monitoring during intracranial surgery for moyamoya disease

We describe our experience with intraoperative electroencephalography in moyamoya surgery, a method to monitor for ischemic changes during the procedure and to minimize the risk of intraoperative and perioperative stroke. Case records and intraoperative electroencephalography recordings of all patients (n=220) treated with surgical revascularization for moyamoya (pial synangiosis) performed for 14 years (1994-2008) were reviewed. Electroencephalographic slowing occurred in 100 cases (45.5%), and was persistent in nine cases (9%). Slowing coincided with specific operative manipulations, most commonly while suturing the donor vessel to the pia, and during closure of the craniotomy. Slowing generally occurred bilaterally, independently of the side of intervention. The presence, length, and severity of slowing were not predictive of perioperative ischemic events. We present additional data on intraoperative electroencephalography with a modified montage to accommodate the craniotomy. Although not predictive of perioperative ischemic events in this series, electroencephalographic changes were correlated with specific operative interventions, and revealed global responses to unilateral manipulation. These findings suggest that prospective analyses of this technique may elucidate additional methods of predicting (and possibly preventing) perioperative ischemic events.

Current proceedings of childhood stroke

Stroke is a sudden onset neurological deficit due to a cerebrovascular event. In children, the recognition of stroke is often delayed due to the low incidence of stroke and the lack of specific assessment measures to this entity. The causes of pediatric stroke are significantly different from that of adult stroke. The lack of safety and efficiency data in the treatment is the challenge while facing children with stroke. Nearly half of survivors of pediatric stroke may have neurologic deficits affecting functional status and quality of life. They may cause a substantial burden on health care resources. Hence, an accurate history, including onset and duration of symptoms, risk factors, and a complete investigation, including hematologic, neuroimaging, and metabolic studies is the key to make a corrective diagnosis. A prompt and optimal treatment without delay may minimize the damage to the brain.

Revascularisation surgery and long-term follow-up in juvenile Moyamoya syndrome: a retrospective analysis

Due to its low incidence in Western countries, physician awareness of juvenile Moyamoya disease should be improved. The benefits of revascularisation surgery have only been proven in the juvenile version of the disease. Therefore, early revascularisation may prevent irreversible ischaemic deficits and rapidly progressive mental retardation in young patients.From 1984 to 2009, a total of 19 children (mean age 8 years, range 1-18 years, female predominance 2:1, 17/19 European white patients, 2/19 Asian origin of at least one parent) were treated for juvenile Moyamoya disease by surgical revascularisation. The leading symptoms were epilepsy (17/19), followed by transient ischaemic attacks (TIA) or prolonged reversible ischaemic neurologic deficits (PRIND) (15/19) and mental retardation (11/19). Angiography showed a clear neovascularisation in the majority of patients after indirect bypasses after 6 months. The mean follow-up was 17 years and 3 months (maximum 25 years, minimum 2 years). Two patients were lost to follow-up. In accordance with the literature, ischaemic symptoms were eliminated by the revascularisation operation in 94% of our patients with a very low rate of complications, and no lasting morbidity and mortality in any of the patients.Early diagnosis and surgical treatment seem to potentiate the benefits independently of the type of revascularisation procedure.

Clinical outcome after 450 revascularization procedures for moyamoya disease

Object

Moyamoya disease (MMD) is a rare cerebrovascular disease mainly described in the Asian literature. To address a lack of data on clinical characteristics and long-term outcomes in the treatment of MMD in North America, the authors analyzed their experience at Stanford University Medical Center. They report on a consecutive series of patients treated for MMD and detail their demographics, clinical characteristics, and long-term surgical outcomes.

Methods

Data obtained in consecutive series of 329 patients with MMD treated microsurgically by the senior author (G.K.S.) between 1991 and 2008 were analyzed. Demographic, clinical, and surgical data were prospectively gathered and neurological outcomes assessed in postoperative follow-up using the modified Rankin Scale. Association of demographic, clinical, and surgical data with postoperative outcome was assessed by chi-square, uni- and multivariate logistic regression, and Kaplan-Meier survival analyses.

Results

The authors treated a total of 233 adult patients undergoing 389 procedures (mean age 39.5 years) and 96 pediatric patients undergoing 168 procedures (mean age 10.1 years). Direct revascularization technique was used in 95.1% of adults and 76.2% of pediatric patients. In 264 patients undergoing 450 procedures (mean follow-up 4.9 years), the surgical morbidity rate was 3.5% and the mortality rate was 0.7% per treated hemisphere. The cumulative 5-year risk of perioperative or subsequent stroke or death was 5.5%. Of the 171 patients presenting with a transient ischemic attack, 91.8% were free of transient ischemic attacks at 1 year or later. Overall, there was a significant improvement in quality of life in the cohort as measured using the modified Rankin Scale (p < 0.0001).

Conclusions

Revascularization surgery in patients with MMD carries a low risk, is effective at preventing future ischemic events, and improves quality of life. Patients in whom symptomatic MMD is diagnosed should be offered revascularization surgery.

Cerebral hemodynamics as a predictor of stroke in adult patients with moyamoya disease: a prospective observational study

Moyamoya disease is an obliterative vasculopathy of the large arteries at the base of the brain. In the US, it most commonly affects women in their 3rd and 4th decades of life, frequently causing ischemic stroke. The natural history of this disorder is not well described. It is very likely that hemodynamic factors play an important role in the risk of future stroke, as has been established in atherosclerotic carotid occlusive disease. The authors describe an ongoing, prospective observational study designed to test the hypothesis that increased oxygen extraction in the cerebral hemisphere beyond the occlusive lesion is a predictor of subsequent risk of ipsilateral stroke in medically treated patients with moyamoya phenomenon. On enrollment, all patients undergo regional measurements of cerebral oxygen extraction fraction (OEF) with PET. Information on baseline clinical, laboratory, epidemiological, and angiographic risk factors are obtained at the time of the PET study. Decisions regarding surgery are made by the treating physicians based on clinical information while being blinded to PET data. Patients undergo follow-up at 6-month intervals to determine the subsequent risk of ipsilateral stroke. All patients will return at 1 and 3 years for repeat PET studies. Secondary, exploratory, aims of this longitudinal and blinded study are to determine other predictive factors for stroke in this population; to determine preliminary estimates of the effects of different medical treatment regimens in this population; to determine the temporal changes in hemodynamic impairment in medically treated patients; to determine the effects of surgery on hemodynamic impairment in the subset of patients who undergo surgical revascularization; and to obtain estimates of surgical complication rates for patients with and without hemodynamic impairment.

Moyamoya disease: a clinical spectrum, literature review and case series from a tertiary care hospital in Pakistan

Background

Moyamoya is a rare cerebrovascular disease of unknown etiology. The data on moyamoya disease from Pakistan is sparse. We report a case series of 13 patients who presented with moyamoya disease to a tertiary care hospital in Pakistan with a national referral base.

Methods

We conducted a retrospective review of thirteen patients who presented to The Aga Khan University and diagnosed with "Moyamoya Disease" during the period 1988 – 2006. These patients were identified from existing hospital database via ICD-9 codes. A predesigned questionnaire containing information about clinical presentation, management and neuroimaging was administered to all identified patients.

Results

There were seven males and six females. Mean age at presentation was 16.5 years and a female predominance was found in the pediatric age group (n = 10, 71.4%). Stroke (n = 11, 84.2%) was the most common presentation with motor deficit being the universal cortical symptom. Fever was a common symptom in the lower age groups (n = 4, 51.7%). Cerebral Angiography and Magnetic Resonance Angiography showed bilateral involvement of the vessels in eleven patients while unilateral in two. Subarachnoid and interventricular haemorrhage appeared in 2(15.4%) adults. Twelve (92.3%) patients were discharged as independent with minor deficits regardless of therapeutic modality. Only three (23.0%) patients underwent surgery whereas the remaining were managed conservatively.

Conclusion

Physicians when dealing with childhood strokes and characteristic deficits in adult population should consider Moyamoya disease.

Ischemic cerebral infarction in an infant following gonadotropin treatment for undescended testes

Cerebrovascular disorders are increasingly recognized as important causes of mortality and morbidity in the pediatric population. Risk factors for stroke in childhood are different from those in adults. Human chorionic gonadotropin is a polypeptide hormone produced by the human placenta and is composed of an alpha-subunit and a beta-subunit. Pregnyl (human chorionic gonadotropin for injection) is a highly purified pyrogen-free preparation obtained from the urine of pregnant females. Ischemic cerebral infarction is seen in the young infertile male and female patients after gonadotropin treatment. The authors describe the case of a boy with right-sided hemiparesis following Pregnyl injection and discuss its possible pathogenetic mechanisms.

Moyamoya disease in pediatric patients: outcomes of neurosurgical interventions

✓Neurosurgical interventions for moyamoya disease (MMD) in pediatric patients include direct, indirect, and combined revascularization procedures. Each technique has shown efficacy in the treatment of pediatric MMD; however, no single study has demonstrated the superiority of one technique over another. In this review, the authors explore the various studies focused on the use of these techniques for MMD in the pediatric population. They summarize the results of each study to clearly depict the clinical outcomes achieved at each institution that had utilized direct, indirect, or combined techniques. In certain studies, multiple techniques were used, and the clinical or radiological outcomes were compared accordingly.

Direct techniques have been shown to aid a reduction in perioperative strokes and provide immediate revascularization to ischemic areas; however, these procedures are technically challenging, and not all pediatric patients are appropriate candidates. Indirect techniques have also shown efficacy in the pediatric population but may require a longer period for revascularization to occur and perfusion deficits to be reversed. The authors concluded that the clinical efficacy of one technique over another is still unclear, as most studies have had small populations and the same outcome measures have not been applied. Authors who compared direct and indirect techniques noted approximately equal clinical outcomes with differences in radiological findings. Additional, larger studies are needed to determine the advantages and disadvantages of the different techniques for the pediatric age group.

Nursing issues in caring for children with moyamoya vasculopathy and their families

Moyamoya vasculopathy is a rare, progressive neurovascular condition that may cause recurrent transient ischemic attacks, ischemic strokes, hemorrhagic strokes, or neurologic decline in children. Children with moyamoya disease have no clear contributing etiology, but children with moyamoya syndrome have contributory diagnoses such as Down syndrome or neurofibromatosis. The concerns and lived experiences of children affected by this disease and their families have not been well explored or addressed in the nursing literature. Nurses who understand this lived experience increase their own knowledge of the disease so they can manage the complex medical issues, educate families about the disease, and provide emotional support.

Primary Percutaneous Transluminal Angioplasty for Early Moyamoya Disease

Moyamoya disease is a progressive steno-oclusive arteriopathy of the circle of Willis that manifests on cerebral angiography with a characteristic net of vessels at the base of the brain representing collateralization. Described initially in Japan where children present with cerebral ischemia and adults with hemorrhagic stroke, it was recognized to have a more benign course in the United States, mainly causing cerebral ischemic events in young adults. Medical treatment is not intended to stop the progression of the disease and surgery is not exempt of risks. We present a patient with early moyamoya disease in the United States in whom primary transluminal angioplasty, a less invasive procedure, was performed to treat the stenotic arteriopathy with good immediate and sustained clinical and angiographic results, without evidence of restenosis at the site of angioplasty 2 years later.

Clinical and Radiological Recurrence After Childhood Arterial Ischemic Stroke

Background— Data on rates and risk factors for clinical and radiological recurrence of childhood arterial ischemic stroke (AIS) might inform secondary prevention strategies.

Methods and Results— Consecutive Great Ormond Street Hospital patients with first AIS were identified retrospectively (1978–1990) and prospectively (1990–2000). Patients underwent repeat neuroimaging at the time of clinical recurrence or, if asymptomatic, at least 1 year after AIS. Cox and logistic regression analyses were used to explore the relationships between risk factors and clinical and radiological recurrence, respectively. A total of 212 patients were identified, of whom 97 had another prior diagnosis. Seventy-nine children had a clinical recurrence (29 strokes, 46 transient ischemic attacks [TIAs], 4 deaths with reinfarction 1 day to 11.5 years (median 267 days) later); after 5 years, 59% (95% confidence interval, 51% to 67%) were recurrence free. Moyamoya on angiography and low birth weight were independently associated with clinical recurrence in the whole group. Genetic thrombophilia was associated with clinical recurrence in previously healthy patients, independent of the presence of moyamoya. Sixty of 179 patients who had repeat neuroimaging had radiological reinfarction, which was clinically silent in 20. Previous TIA, bilateral infarction, prior diagnosis (specifically immunodeficiency), and leukocytosis were independently associated with reinfarction. Previous TIA and leukocytosis were also independently associated with clinically silent reinfarction.

Conclusions— Clinical and radiological recurrence are common after childhood AIS. The risk of clinical recurrence is increased in children with moyamoya and, in previously healthy patients, in those with genetic thrombophilia. Preexisting pathology, including immunodeficiency, and persistent leukocytosis are risk factors for radiological recurrence, which suggests a potential role for chronic infection.

Unilaterally Symptomatic Moyamoya Disease in Children: Long-term Follow-up of 20 Patients

OBJECTIVE:

In unilaterally symptomatic moyamoya disease in children, it remains controversial whether bypass surgery should be performed on the asymptomatic side along with on the symptomatic side. We aimed to verify the validity of our strategy of only performing bypass surgery on the symptomatic side.

METHODS:

Among 91 pediatric patients with moyamoya disease who underwent bypass surgery in our department between 1980 and 2004, 20 with unilateral ischemic symptoms who were followed for more than 60 months were analyzed in the present study. Initially, we only performed bypass surgery on the symptomatic side for all 20 patients. Among these 20 patients, five developed frequent transient ischemic attacks in the initially asymptomatic side and underwent a second bypass surgery on that side (Group A), eight developed sporadic transient ischemic attacks and were followed up without surgery (Group B), and seven did not experience any ischemic symptoms on the asymptomatic side (Group C).

RESULTS:

In total, 18 patients progressed well without cerebral infarctions after their last surgery, although some showed deterioration of angiographic stenosis and a transient decrease in the regional cerebral blood flow or cerebral perfusion reserve. One patient in Group A had an intraventricular hemorrhage 5 years after the second operation, and one in Group B had a minor stroke on the initially asymptomatic side.

CONCLUSION:

In unilaterally symptomatic moyamoya disease, bypass surgery for the asymptomatic side can be delayed until the development of ischemic symptoms, such as frequent transient ischemic attacks.