Surgical management of moyamoya syndrome

Advances in moyamoya disease: pathogenesis, diagnosis, and therapeutic interventions

Moyamoya disease (MMD) is a type of cerebrovascular disease characterized by occlusion of the distal end of the internal carotid artery and the formation of collateral blood vessels. Over the past 20 years, the landscape of research on MMD has significantly transformed. In this review, we provide insights into the pathogenesis, diagnosis, and therapeutic interventions in MMD. The development of high-throughput sequencing technology has expanded our understanding of genetic susceptibility, identifying MMD-related genes beyond RNF213, such as ACTA2, DIAPH1, HLA, and others. The genetic susceptibility of MMD to its pathological mechanism was summarized and discussed. Based on the second-hit theory, the influences of inflammation, immunity, and environmental factors on MMD were also appropriately summarized. Despite these advancements, revascularization surgery remains the primary treatment for MMD largely because of the lack of effective in vivo and in vitro models. In this study, 16 imaging diagnostic methods for MMD were summarized. Regarding therapeutic intervention, the influences of drugs, endovascular procedures, and revascularization surgeries on patients with MMD were discussed. Future research on the central MMD vascular abnormalities and peripheral circulating factors will provide a more comprehensive understanding of the pathogenic mechanisms of MMD.

Orofacial features and dental management of a pediatric patient with moyamoya disease-A one year follow up

Key Clinical Message

Moyamoya disease (MMD) is a chronic cerebrovascular disorder increasing stroke risk. This study presents a four-year-old MMD patient, discussing her multidisciplinary care plan including dental, behavioral, and medical management. It emphasizes the need for awareness among oral physicians and suggests further research due to the rising prevalence of MMD.

Abstract

Moyamoya disease (MMD) is a chronic cerebrovascular disorder that narrows major blood vessels in the brain, reduces blood flow, and increases the risk of stroke. The purposes of this study were to: (1) present the case of a four-year-old patient diagnosed with MMD; (2) discuss important aspects of her multidisciplinary care plan involving dental, behavioral, and medical management; and (3) suggest approaches and recommendations for health care providers. A four-year-old Middle Eastern female diagnosed with MMD, neurogenic bladder, chronic constipation, hyperactivity, and delayed milestones presented to the dental clinic with her parents seeking dental care. The child was referred by a pediatric neurologist for dental care. In the present case, there were no specific oral manifestations. However, oral physicians should be aware of possible behavioral management modalities when providing dental care to pediatric patients, including those diagnosed with MMD.

Update on the anesthesia management in adult patients with moyamoya disease

PURPOSE OF REVIEW

The anesthetic management of patients with Moyamoya disease (MMD) is challenging and continues to evolve. The goal of this review is to provide updated recommendations on the anesthetic management of adult MMD patients based on the relevant existing literature.

RECENT FINDINGS

Key findings include the importance of aggressive hydration preoperatively to sustain cerebral perfusion. Hypertension induced intraoperatively may prevent cerebral hypoperfusion. Vigilance against cerebral hyperperfusion after revascularization is necessary, with specific blood pressure targets recommended. Fluid management should aim for normovolemia to mild hypervolemia. Maintaining body temperature helps prevent cerebral vasospasm induced by hypothermia. Maintaining adequate oxygen supply during surgery is crucial. In cases of ischemic stroke, managing hematocrit and oxygen carrying capacity is essential to prevent further ischemia. Extubation decisions should consider baseline neurological function, while postoperative normocapnia helps prevent cerebral hyperperfusion and hypertension. In intensive care, cautious blood pressure management is crucial to prevent secondary complications.

SUMMARY

Strategies in the preoperative, intraoperative, and postoperative anesthetic management of MMD patients should aim to maintain adequate cerebral perfusion to prevent cerebral ischemia.

Clinical Case of a 23-Year-Old Patient with Moyamoya Disease and Epilepsy in Bulgaria

Moyamoya disease is a cerebrovascular pathology characterized by progressive stenosis of the internal carotid arteries and their branches, leading to ischemic and/or hemorrhagic disorders of the cerebral circulation, primarily affecting children and young adults. We present a case of a 23-year-old woman with a history of recurrent cerebrovascular accidents since childhood. Despite experiencing focal motor seizures and transient ischemic attacks, her condition remained undiagnosed until 2006, when, at the age of 7, a digital subtraction angiography revealed characteristic bilateral internal carotid artery occlusions. Subsequent diagnostic challenges and treatments preceded a worsening of symptoms in adulthood, including generalized tonic-clonic seizures. Upon presentation to our clinic, the patient exhibited upper motor neuron syndrome and occipital lobe syndrome, consistent with the disease's pathophysiology, neuroimaging, and clinical manifestations. Imaging studies confirmed multiple ischemic lesions throughout the cerebral vasculature. Treatment adjustments were made due to the increased incidence of seizures, and the dose of her anti-seizure medication-divalproex sodium-was increased. This case underscores the diagnostic complexities and challenges in managing moyamoya disease, emphasizing the importance of early recognition and prompt intervention.

An Unusual Presentation of Moyamoya Disease in a Pediatric Patient

Moyamoya disease (MMD) is a chronic cerebro-vasculopathy that is extremely rare in the pediatric population. The main characteristic feature is the progressive stenosis in the internal carotid artery with or without the involvement of its main branches in the circle of Willis leading to ischemic stroke. Patients have clinical manifestations related to cerebral ischemia in the carotid branch territories, such as sensory impairment, hemiparesis, and aphasia/dysarthria. Herein, we report a case of MMD in a six-year-old Emirati female who presented with unusual manifestations of MMD in the form of headache, vomiting, and double vision and was diagnosed with MMD based on a brain MRI with angiography. To our knowledge, this is the first reported case of MMD in the United Arab Emirates.

Rare combo: moyamoya and lupus in men

Moyamoya syndrome (MMS) is a rare, chronic, progressive cerebrovascular disorder characterized by stenosis at the apices of the intracranial internal carotid arteries, including the proximal anterior cerebral arteries and middle cerebral arteries. Cerebral angiography images are used for detection through measurement. Systemic lupus erythematosus (SLE) is an autoimmune disease that can cause multisystemic involvement. The coexistence of SLE and MMS has been rarely reported in the literature. A 46-year-old male patient with malar rash, Raynaud phenomenon presented to the hospital with a complaint of weakness in the left lower extremity, which began 3 days before the date of the visit. In the diffusion magnetic resonance imaging, multiple diffusion restrictions were observed in the right frontal region. The patient underwent MR angiography, revealing stenosis in the terminal and supraclinoid segments of the right internal carotid artery, which made us consider moyamoya disease. This patient, with a malar rash and Raynaud's, a positive antibody profile, was diagnosed as a male with SLE accompanied by MMS.

Direct Versus Indirect Revascularization for Moyamoya: a Large Multicenter Study

BACKGROUND

Moyamoya is a chronic occlusive cerebrovascular disease of unknown etiology causing neovascularization of the lenticulostriate collaterals at the base of the brain. Although revascularization surgery is the most effective treatment for moyamoya, there is still no consensus on the best surgical treatment modality as different studies provide different outcomes.

OBJECTIVE

In this large case series, we compare the outcomes of direct (DR) and indirect revascularisation (IR) and compare our results to the literature in order to reflect on the best revascularization modality for moyamoya.

METHODS

We conducted a multicenter retrospective study in accordance with the Strengthening the Reporting of Observational studies in Epidemiology guidelines of moyamoya affected hemispheres treated with DR and IR surgeries across 13 academic institutions predominantly in North America. All patients who underwent surgical revascularization of their moyamoya-affected hemispheres were included in the study. The primary outcome of the study was the rate of symptomatic strokes.

RESULTS

The rates of symptomatic strokes across 515 disease-affected hemispheres were comparable between the two cohorts (11.6% in the DR cohort vs 9.6% in the IR cohort, OR 1.238 (95% CI 0.651 to 2.354), p=0.514). The rate of total perioperative strokes was slightly higher in the DR cohort (6.1% for DR vs 2.0% for IR, OR 3.129 (95% CI 0.991 to 9.875), p=0.052). The rate of total follow-up strokes was slightly higher in the IR cohort (8.1% vs 6.6%, OR 0.799 (95% CI 0.374 to 1.709) p=0.563).

CONCLUSION

Since both modalities showed comparable rates of overall total strokes, both modalities of revascularization can be performed depending on the patient's risk assessment.

Effect of cerebral oxygen saturation monitoring in patients undergoing superficial temporal anterior-middle cerebral artery anastomosis for ischemic Moyamoya disease: a prospective cohort study

Objective

Regional cerebral oxygen saturation (rSO2) is linked with blood pressure. This study evaluated the influence of perioperative rSO2 monitoring on the prognosis of ischemic Moyamoya disease (MMD) patients undergoing anastomosis surgery.

Methods

In this prospective cohort, patients with unilateral ischemic MMD of Suzuki stage ≥3 were included. The decision of rSO2 was made by the clinician and the patient. The rSO2 group maintained intraoperative rSO2 levels through the modulation of blood pressure, inhaled oxygen concentration, carbon dioxide in arterial blood, and red blood cell transfusion. The non-rSO2 group used conventional anesthesia practices. Perioperative mean arterial pressure (MAP), rSO2 values, neurological complications, and postoperative results were assessed.

Results

A total of 75 eligible patients were categorized into a rSO2 monitoring group (n = 30) and a non-rSO2 monitoring group (n = 45). For the rSO2 group, the preoperative rSO2 was significantly lower on the affected side (P < 0.05). After anastomosis, this value notably increased (P = 0.01). A moderate relationship was observed between perioperative rSO2 and MAP before, during, and after surgery, with correlation coefficients (r) of 0.536, 0.502, and 0.592 (P < 0.05). Post-surgery MAP levels differed between the groups, with the rSO2 group showing decreased levels compared to pre-surgery and the non-rOS2 group displaying elevated levels. Notably, the rSO2 group reported shorter hospitalizations and decreased neurological complications. Patients with a hypertension history found postoperative MAP influencing hospital stay duration.

Conclusion

Perioperative rSO2 surveillance enhanced cerebral perfusion and minimized postoperative complications in ischemic MMD patients. Thus, rSO2 monitoring is advocated for MMD patients undergoing vascular anastomosis.

Metabolism changes during direct revascularization in moyamoya disease: illustrative case

BACKGROUND

Cerebral revascularization is recommended for patients with moyamoya disease (MMD) with reduced cerebral perfusion reserve and recurrent or progressive ischemic events. The standard surgical treatment for these patients is a low-flow bypass with or without indirect revascularization. The use of intraoperative monitoring of the metabolic profile using analytes such as glucose, lactate, pyruvate, and glycerol has not yet been described during cerebral artery bypass surgery for MMD-induced chronic cerebral ischemia. The authors aimed to describe an illustrative case using intraoperative microdialysis and brain tissue oxygen partial pressure (PbtO2) probes in a patient with MMD during direct revascularization.

OBSERVATIONS

The patient's severe tissue hypoxia situation was confirmed by a PbtO2:partial pressure of oxygen (PaO2) ratio below 0.1 and anaerobic metabolism by a lactate:pyruvate ratio greater than 40. Following bypass, a rapid and sustained increase in PbtO2 up to normal values (PbtO2:PaO2 ratio between 0.1 and 0.35) and the normalization of cerebral energetic metabolism with a lactate/pyruvate ratio less than 20 was observed.

LESSONS

The results show a quick improvement of regional cerebral hemodynamics due to the direct anastomosis procedure, reducing the incidence of subsequent ischemic stroke in pediatric and adult patients immediately.

Early Surgery for Moyamoya Is Not Associated with Worse Outcomes: Analysis of a North American Adult Cohort

BACKGROUND

Patients with symptomatic moyamoya disease (MMD) or moyamoya syndrome (MMS) are at high risk of recurrent stroke. Surgical revascularization with either direct or indirect superficial temporal artery to middle cerebral artery bypass is a well-accepted treatment. However, the optimal timing and surgical technique for adult patients with MMD or MMS remain unknown.

METHODS

We performed a retrospective medical record review of patients who had undergone superficial temporal artery to middle cerebral artery bypass for MMD or MMS from January 1, 2017, to January 1, 2022. The data collected included demographics, comorbidities, complications, as well as angiographic, and clinical outcomes. Early surgery was defined as surgery performed ≤2 weeks of the last stroke and delayed surgery as surgery performed >2 weeks after the last stroke. In the statistical analysis, we compared early versus delayed surgery and direct versus indirect bypass.

RESULTS

Nineteen patients had undergone bypass surgery on 24 hemispheres. Of the 24 cases, 10 were early and 14 were delayed. In addition, 17 were direct, and 7 were indirect. No statistically significant difference was found in total complications between the early (3 of 10; 30%) and delayed (3 of 14; 21%; P = 0.67) groups. Five complications occurred in the direct group (5 of 17; 29%) and one in the indirect group (1 of 7; 14%; P = 0.63). No mortalities related to surgery occurred. Angiographic follow-up showed more extensive revascularization after early direct bypass than after delayed indirect bypass.

CONCLUSIONS

In our population of North American adults who had undergone surgical revascularization for MMD or MMS, early surgery within 2 weeks of the last stroke did not differ from delayed surgery in terms of complications or clinical outcomes. Early direct bypass showed more revascularization on angiography than did delayed indirect surgery.

Effects of superficial temporal artery to middle cerebral artery bypass on postoperative infarction rates among young children (≤ 5 years old) with moyamoya disease

Revascularization surgery for young children with moyamoya disease (MMD) is challenging. Although indirect revascularization is preferred because of the technical difficulty in direct anastomosis, higher risks of postoperative infarction remain a problem. We aimed to investigate the effect of superficial temporal artery to middle cerebral artery (STA-MCA) bypass on postoperative outcomes during the acute postoperative period in young children ≤ 5 years old with MMD. This retrospective study included consecutive young children with MMD who underwent surgical revascularization of the anterior cerebral circulation. Groups were determined according to the procedures performed, namely, the combined (STA-MCA bypass with indirect revascularization) and the indirect revascularization groups. The incidences of radiological or symptomatic infarction, transient neurological events, and new neurological deficits that remained at discharge were compared between groups. Of 38 surgical procedures, there were 23 combined and 15 indirect revascularizations. The median age of the patients was 3.0 years, which was significantly different between groups (P < .01). When comparing the postoperative outcomes between groups, the incidences of radiological and symptomatic infarction and new neurological deficits that remained at discharge were significantly lower in the combined revascularization group (P < .05). Logistic regression analysis adjusted for potential confounders found that surgical modality was a statistically significant independent risk factor associated with radiological and symptomatic infarctions (indirect/combined, odds ratio: 10.2; 95% confidence interval: 1.30-79.7; P < .05). STA-MCA bypass combined with indirect revascularization can reduce the incidence of postoperative infarction in young children with MMD and might lead to better neurological outcomes.

Response of internal carotid artery blood flow velocity to fluid challenge under general anesthesia in pediatric patients with moyamoya disease: A prospective observational study

BACKGROUND

Maintaining cerebral blood flow is important in intraoperative management of moyamoya disease patients.

AIMS

To access changes in the carotid artery blood flow velocity in response to fluid challenge, blood pressure, and cardiac output under general anesthesia in pediatric patients with moyamoya disease.

METHODS

This observational study included pediatric patients with moyamoya disease undergoing general anesthesia for encephaloduroarteriosynangiosis. Each patient underwent an ultrasound assessment thrice as follows: after anesthetic induction (T1), after fluid challenge (10 ml/kg, T2), and at the end of surgery (T3). The primary outcome was the change in the internal carotid artery blood flow velocity after fluid challenge and was assessed using a paired t-test. The secondary outcomes comprised changes in the internal, external, and common carotid artery blood flow peak velocities after fluid challenge and the factors influencing these changes.

RESULTS

We enrolled and analyzed 30 patients with a mean age of 7.2 years. After fluid challenge, the systolic (p = .003) and mean blood pressure (p = .017), stroke volume index (p = .008), and cardiac index (p = .140) were higher than those at T1. However, both internal carotid artery blood flow velocities did not change after fluid challenge (p = .798, mean difference and 95% confidence interval [CI], -1.1 and -10.3 to 8.0 for right, p = .164, mean difference and 95% CI, -5.2 and -12.7 to 2.2 for left). The internal carotid artery blood flow velocity was correlated with the cardiac index, stroke volume index, and mean and diastolic blood pressure, with low significance.

CONCLUSIONS

The internal carotid artery blood flow velocity did not increase in pediatric patients with moyamoya disease under general anesthesia, despite fluid challenge and corresponding changes in the blood pressure and cardiac output. Intraoperative hemodynamic management to improve the cerebral blood flow in these patients requires further investigation.

Wide Arterial Sparing Encephalo-Duro-Synangiosis for Moyamoya: Surgical Technique and Outcomes

BACKGROUND

Moyamoya is managed by surgical revascularization, but no standardized method has yet been universally adopted.

OBJECTIVE

To describe a new indirect bypass technique for pediatric moyamoya, wide arterial sparing encephalo-duro-synangiosis (WASEDS), which provides a much wider area of revascularization with minimal compromise to the middle meningeal arterial tree compared with traditional procedures. Initially used as a salvage technique after failed encephalo-duro-arterio-synangiosis, its success later motivated its use as a first-line procedure.

METHODS

Clinical and radiographic records of patients who underwent WASEDS for moyamoya from 2009 to 2020 were reviewed. Brain perfusion relative cerebral blood volume on the side of the WASEDS procedure was calculated. Two-tailed paired t tests were performed to identify the statistically significant differences ( P ≤ .05).

RESULTS

WASEDS was successfully performed on 8 patients for a total of 14 cerebral hemispheres. Age ranged from 2 to 25 years. There were no mortalities. The average clinical and radiographic follow-up was 49.79 months (range 2-126 months), demonstrating improvement in neurological condition and no postoperative stroke and significant diminution or cessation of transient ischemic attacks in all patients. Relative cerebral blood volume increased 9.24% after the WASEDS procedure ( P = .012). There were no neurological complications. There were 2 pseudomeningoceles related to the extensive dural openings.

CONCLUSION

WASEDS is a safe and effective indirect revascularization technique for both primary and salvage techniques. It provides an extensive area of cortical revascularization with no compromise of the middle meningeal vasculature and subjective reports of early improvement in cognition and behavior. The main disadvantage is elevated risk of pseudomeningocele secondary to the large craniotomy.

Surgical techniques and indications for treatment of adult moyamoya disease

Moyamoya disease (MMD) is a chronic, progressive cerebrovascular disease involving the occlusion or stenosis of the terminal portion of the internal carotid artery (ICA) and the proximal anterior and middle cerebral arteries. Adults with MMD have been shown to progressively accumulate neurological and cognitive deficits without treatment, with a mortality rate double that of pediatric patients with MMD. Surgical intervention is the mainstay of treatment to prevent disease progression and improve clinical outcomes. Several different types of bypasses can be utilized for revascularization in MMD, including indirect, direct, and combined forms of extracranial-to-intracranial (EC-IC) bypass. Overall, the choice of appropriate technique requires consideration of the age of the patient, preoperative hemodynamics, neurologic status, and territories most at risk and in need of revascularization. Here, we will review the indications and surgical techniques for the treatment of adult MMD. Step-by-step instructions for performing several bypass variants with technical pearls are discussed.

"Recycling" a failed superficial temporal artery indirect bypass into a double barrel direct bypass in moyamoya disease

OBJECTIVES

Moyamoya disease is an idiopathic cerebrovascular disorder in which patients experience recurrent transient ischemic attacks, ischemic or hemorrhagic strokes, headaches, and seizures from progressive stenosis of the vessels of the anterior circulation. The mainstay of treatment in symptomatic patients is surgical revascularization. Here, we present the case of a moyamoya patient in which a failed encephaloduroarteriosynangiosis, after new strokes, is recycled and converted into a combined "double barrel" direct superficial temporal artery to middle cerebral artery bypass with included video.

CASE REPORT/RESULTS

We describe a 37-year-old woman with a history of hypertension, obstructive sleep apnea, celiac disease, and moyamoya disease complicated by multiple ischemic strokes who presented with progressive dysarthria, dysphagia, and new left-sided ischemic infarcts. The patient had previously undergone right-sided direct bypass and left-sided encephaloduroarteriosynangiosis in the setting of multiple ischemic strokes. After more strokes, the patient underwent a left-sided frontotemporoparietal craniotomy for conversion of the failed indirect bypass into a "double barrel" direct bypass.

CONCLUSIONS

The literature is divided over which revascularization procedure should be preferred. Irrespectively, most failed bypass grafts are repaired via direct bypasses, to good effect. We highlight a case in which a failed indirect bypass is directly incorporated into a combined direct bypass with resulting restoration of blood flow. In the case of a failed indirect bypass in an adult patient with moyamoya disease, this method provides the operator with an additional option for restoration of perfusion, especially in patients without other viable vessels available for anastomosis.

Strategic tunnelling of superficial temporal artery during bypass surgery for moyamoya disease

BACKGROUND

The superficial temporal artery to middle cerebral artery bypass remains the favoured direct technique of cerebral revascularization in moyamoya angiopathy. We describe a novel technique of tunnelling the superficial temporal artery through the temporalis muscle.

METHODS

The temporalis muscle is raised as a flap off the temporal bone. A triangular window is created on the temporalis fascia, and a tunnel is created for the superficial temporal artery to pass through the muscle belly.

CONCLUSION

This innovative technique allows passage of the superficial temporal artery to the brain without kink or compression ensuring good bypass function and improves long-term patency.

Spatially separate cerebral infarction in the posterior cerebral artery territory after combined revascularization of the middle cerebral artery territory in an adult patient with moyamoya disease and fetal-type posterior communicating artery: illustrative case

BACKGROUND

Remote cerebral infarction after combined revascularization of the middle cerebral artery (MCA) territory is rare in patients with moyamoya disease (MMD) with a fetal-type posterior communicating artery (PCoA).

OBSERVATIONS

A 57-year-old woman developed numbness in her right upper limb and transient motor weakness and was diagnosed with MMD. She also had a headache attack and a scintillating scotoma in the right visual field. Preoperative magnetic resonance angiography (MRA) showed stenosis of the left posterior cerebral artery (PCA). Combined revascularization was performed for the left MCA territory. No new neurological deficits were observed for 2 days after the operation, but right hemianopia, alexia, and agraphia appeared on postoperative day (POD) 4. Magnetic resonance imaging showed a new left occipitoparietal lobe infarction, and MRA showed occlusion of the distal left PCA. After that point, the alexia and agraphia gradually improved, but right hemianopia remained at the time of discharge on POD 18.

LESSONS

Cerebral ischemia in the PCA territory may occur after combined revascularization of the MCA territory in patients with fetal-type PCoA. For these cases, a double-barrel bypass or indirect revascularization to induce a slow conversion could be considered on its own as a treatment option.

Paradoxical symptomatic cerebral blood flow decreases after combined revascularization surgery for patients with pediatric moyamoya disease: illustrative case

BACKGROUND

Transient neurological deficits (TNDs) develop after cerebral revascularization in patients with moyamoya disease (MMD). The authors report a rare pediatric MMD case with extensive decreased cerebral blood flow (CBF) and prolonged TNDs after combined revascularization.

OBSERVATIONS

A 9-year-old boy presented with transient left upper limb weakness, and MMD was diagnosed. A right-sided combined surgery was performed. Two years after the surgery, frequent but transient facial (right-sided) and upper limb weakness appeared. The left internal carotid artery terminal stenosis had progressed. Therefore, a left combined revascularization was performed. The patient’s motor aphasia and right upper limb weakness persisted for approximately 10 days after surgery. Magnetic resonance angiography showed that the direct bypass was patent, but extensive decreases in left CBF were observed using single photon emission tomography. With adequate fluid therapy and blood pressure control, the neurological symptoms eventually disappeared, and CBF improved.

LESSONS

The environment of cerebral hemodynamics is heterogeneous after cerebral revascularization for MMD, and the exact mechanism of CBF decreases was not identified. TNDs are significantly associated with the onset of stroke during the early postoperative period. Therefore, appropriate treatment is desired after determining complex cerebral hemodynamics using CBF studies.

Optimizing management of sickle cell disease in patients undergoing surgery

Individuals with sickle cell disease (SCD) are likely to be referred for surgery at some point in their lifetime due to a high incidence of musculoskeletal and intrabdominal complications such as avascular necrosis and gallbladder disease. Preoperative optimization is a multidisciplinary process that involves a hematologist with SCD expertise, an anesthesiologist, and the surgical team. The type and risk classification of the surgery, disease severity, medications, baseline hemoglobin, transfusion history, and history of prior surgical complications are often documented. Clinicians should consider perioperative risk assessment that includes determining the patient's functional status and cardiovascular risk and screening for obstructive sleep apnea. Many patients will require preoperative transfusion to reduce the risk of postoperative complications such as acute chest syndrome and vaso-occlusive pain crises. The hematologist should consider the patient's preoperative transfusion requirements and ensure that the surgical team has an appropriate plan for postoperative observation and management. This often includes follow-up laboratory studies, a postoperative pain management plan, and venous thromboembolism prophylaxis. The transfusion plan should be patient-specific and take into account the SCD genotype, baseline hemoglobin, disease severity, risk classification of the surgery, and history of prior surgical complications. In the intraoperative and postoperative period, dehydration, hypothermia, hypotension, hypoxia, and acidosis should be avoided, and incentive spirometry should be utilized to minimize complications such as acute chest syndrome. In this review we discuss preoperative, intraoperative, and postoperative strategies to optimize patients with SCD undergoing surgery.

Central nervous system vasculopathy and Seckel syndrome: case illustration and systematic review

PURPOSE

To systematically review reported cases of Seckel syndrome (SS) and point out cases associated with central nervous system (CNS) vasculopathy and provide a summary of their clinical presentation, management, and outcomes including our illustrative case.

METHODS

We conducted a search on the MEDLINE, PubMed, Google Scholar, and Cochrane databases using the keywords "Seckel + syndrome." We identified 127 related articles reporting 252 cases of SS apart from our case. Moreover, we searched for SS cases with CNS vasculopathies from the same databases. We identified 7 related articles reporting 7 cases of CNS vasculopathies in SS patients.

RESULTS

The overall rate of CNS vasculopathy in SS patients is 3.16% (n = 8/253), where moyamoya disease (MMD) accounted for 1.97%. The mean age is 13.5 years (6-19 years), with equal gender distribution (M:F, 1:1). The most common presenting symptoms were headache and seizure followed by weakness or coma. Aneurysms were mostly located in the basilar artery, middle cerebral artery, and internal carotid artery, respectively. Regardless of the management approach, 50% of the cases sustained mild-moderate neurological deficit, 37.5% have died, and 12.5% sustained no deficit.

CONCLUSION

A high index of suspicion should be maintained in (SS) patients, and MMD should be part of the differential diagnosis. Prevalence of CNS vasculopathy in SS is 3.16% with a much higher prevalence of MMD compared to the general population. Screening for cerebral vasculopathy in SS is justifiable especially in centers that have good resources. Further data are still needed to identify the most appropriate management plan in these cases.

Current trends in pediatric moyamoya: a survey of international practitioners

OBJECTIVE

Moyamoya angiopathy (MM) is a chronic, progressive steno-occlusive arteriopathy of the distal internal carotid artery and its proximal branches. MM is recognized as a shared end-pathway common to a broad range of inciting pathologies, suggesting that tailored management is important. Pediatric MM differs from MM in adults. Currently, there are many uncertainties and controversies regarding the diagnosis and management of children with MM. Hence, we conducted an international survey to identify the contemporary management trends followed worldwide.

METHODS

A survey relating to lifestyle modifications, medical management, diagnosis, surgical management, and follow-up for pediatric MM was circulated across web-based platforms, through various international pediatric neurological and neurosurgical societies. Data collected included geographic region of practice, experience, responses to questions, and comments.

RESULTS

One hundred twenty-seven responses were evaluated (104 neurosurgeons and 23 neurologists, from 32 countries, across 6 continents). We found wide variations in the recommendations for management and lifestyle modification, with significant differences between regions of practice. Eighty percent recommend restrictions on physical activity, particularly for symptomatic and non-operated patients. Eighty-four percent prescribe aspirin. Sixty-five percent perform indirect revascularization. Seventy-eight percent recommend performing a staged surgery for bilateral MM. Only 26% perform acetazolamide challenge SPECT to evaluate brain perfusion. Only 15% of responders were from highly experienced centers.

CONCLUSION

This survey reflects the contemporary trends in management of pediatric MM, while highlighting the heterogeneity in the management approach of these patients. There is a need for multicenter, international studies to evaluate the safety, efficacy, and long-term outcome of various aspects of treatment of these patients.

Cerebral arteriopathy in ACTA2 mutations: a spectrum of disease highlighted by a case of variable penetrance in two siblings

Until recently, cerebral arteriopathy due to heterozygous mutations of the ACTA2 gene was considered a variant of moyamoya disease. However, radiographic analysis of patients with these mutations reveals a distinctive angiographic appearance from that seen in moyamoya disease. Several heterozygous missense ACTA2 mutations have been implicated in the development of this distinct cerebrovascular entity; however, the penetrance and systemic manifestations of these mutations vary based on the location of the amino acid replacement within the α-smooth muscle actin protein. The severity of the phenotype may also differ among patients within a single mutation type. There is limited literature on the safety and efficacy of revascularization procedures for ACTA2 arteriopathy, which have been limited to those patients with known Arg179His mutations. The authors provide a review of the breadth of mutations within the ACTA2 literature and report a case of two siblings with de novo ACTA2 Arg258Cys mutations with differing clinical courses, highlighting the utility of indirect revascularization with 8-year follow-up data. This case highlights the importance of early recognition of the angiographic appearance of ACTA2 cerebral arteriopathy and performance of genetic testing, as the location of the mutation impacts clinical presentation and outcomes.

Linking cortical astrocytic neogenin deficiency to the development of Moyamoya disease-like vasculopathy

Moyamoya-like vasculopathy, the "puff of smoke"-like small vessels in the brain, is initially identified in patients with Moyamoya disease (MMD), a rare cerebrovascular disease, and later found in patients with various types of neurological conditions, including Down syndrome, Stroke, and vascular dementia. It is thus of interest to understand how this vasculopathy is developed. Here, we provided evidence for cortical astrocytic neogenin (NEO1) deficiency to be a risk factor for its development. NEO1, a member of deleted in colorectal cancer (DCC) family netrin receptors, was reduced in brain samples of patients with MMD. Astrocytic Neo1-loss resulted in an increase of small blood vessels (BVs) selectively in the cortex. These BVs were dysfunctional, with leaky blood-brain barrier (BBB), thin arteries, and accelerated hyperplasia in veins and capillaries, resembled to the features of moyamoya-like vasculopathy. Additionally, we found that both MMD patient and Neo1 mutant mice exhibited altered gene expression in their cortex in proteins critical for not only angiogenesis [e.g., an increase in vascular endothelial growth factor (VEGFa)], but also axon guidance (e.g., netrin family proteins) and inflammation. In aggregates, these results suggest a critical role of astrocytic NEO1-loss in the development of Moyamoya-like vasculopathy, providing a mouse model for investigating mechanisms of Moyamoya-like vasculopathy.

Case Report: Cerebral Revascularization in a Child With Mucopolysaccharidosis Type I

Mucopolysaccharidosis (MPS) type I is a rare lysosomal storage disorder caused by an accumulation of glycosaminoglycans (GAGs) resulting in multisystem disease. Neurological morbidity includes hydrocephalus, spinal cord compression, and cognitive decline. While many neurological symptoms have been described, stroke is not a widely-recognized manifestation of MPS I. Accordingly, patients with MPS I are not routinely evaluated for stroke, and there are no guidelines for managing stroke in patients with this disease. We report the case of a child diagnosed with MPS I who presented with overt stroke and repeated neurological symptoms with imaging findings for severe ventriculomegaly, infarction, and bilateral terminal carotid artery stenosis. Direct intracranial pressure evaluation proved negative for hydrocephalus. The patient was subsequently treated with cerebral revascularization and at a 3-year follow-up, the patient reported no further neurological events or new ischemia on cerebral imaging. Cerebral arteriopathy in patients with MPS I may be associated with GAG accumulation within the cerebrovascular system and may predispose patients to recurrent strokes. However, further studies are required to elucidate the etiology of cerebrovascular arteriopathy in the setting of MPS I. Although the natural history of steno-occlusive arteriopathy in patients with MPS I remains unclear, our findings suggest that cerebral revascularization is a safe treatment option that may mitigate the risk of future strokes and should be strongly considered within the overall management guidelines for patients with MPS I.

Surgical Approaches to Stroke Risk Reduction

PURPOSE OF REVIEW

Surgical vascular intervention is an important tool in reducing the risk of stroke. This article examines the evidence for using the available options.

RECENT FINDINGS

Carotid endarterectomy is an effective treatment option for reducing the risk of stroke in appropriately selected patients. Patients should be stratified for future stroke risk based on both the degree of stenosis and the presence of symptoms referable to the culprit lesion. Carotid stenting is also useful in reducing stroke risk, again in carefully selected patients. Because of the publication of significant data regarding both carotid endarterectomy and carotid artery stenting in the last several years, selection can be far more personalized and refined for individual patients based on demographics, sex, patient preference, and medical comorbidities. Routine extracranial-intracranial bypass surgery remains unproven as a therapeutic option for large vessel occlusion in reducing the incidence of ischemic stroke although some carefully screened patient populations remaining at high risk may benefit; procedural risks and pathology related to alterations in blood flow dynamics are challenges to overcome. Indirect revascularization remains an appropriate solution for carefully selected patients with cerebral large vessel steno-occlusive disease, and multiple variations of surgical technique are patient specific. Indirect revascularization may benefit from clinical trials with larger patient populations for validation in specific pathologies and offers the advantages of lower surgical complication rates and reduced risk of pathologic responses to altered cerebral flow dynamics.

SUMMARY

Surgical solutions to reduce stroke risk provide important alternatives in appropriately selected patients and should be considered in addition to medical management and lifestyle modification for optimizing patient outcomes.

Moyamoya-like vasculopathy associated to MYH9-related thrombocytopenia manifested by multiple cerebral ischemic lesions: a case report

Background

Moyamoya-like vasculopathy (MMV) and myosin heavy chain 9-related platelet disorders (MYH9-RPDs) or macrothrombocitopenias are rare syndromes. Their association is even more infrequent.

Case presentation

A 29-year-old female with history of MYH9-RPD, presented to our department for episodes suggesting transient ischemic attacks. Based on the imaging studies that revealed multiple ischemic lesions and stenoses of both distal internal carotid arteries and the arteries of the circle of Willis, the diagnosis of MMV was established. The treatment with Verapamil was initiated, leading to symptom remission. Two months later, the patient presented one episode of dysarthria, followed by involuntary movements of the right upper limb, few days later. Long-term electroencephalogram monitoring depicted epileptiform abnormalities. Resolution of symptoms was obtained after increasing the dose of Verapamil, and initiating Levetiracetam.

Conclusions

This is an interesting case of a patient with two rare pathologies, who presented with cerebral ischemic strokes. To our knowledge there are few cases described in the literature presenting with cerebral hemorrhagic events but none of them with multiple cerebral ischemic lesions. As these cases are very rare, it is important to gather evidence regarding the best approach and treatment strategy.

Clinical outcomes after revascularization for pediatric moyamoya disease and syndrome: A single-center series

Moyamoya is a progressive cerebrovascular arteriopathy that affects children of any age. The goal of this study was to determine imaging and clinical outcomes as well as complication rates in a pediatric cohort undergoing either a combined direct/indirect or indirect-only revascularization approach. Patients with moyamoya disease or syndrome ≤ 18 years of age at the time of initial surgery were identified, and clinical data were collected retrospectively. Over a 12-year period, 26 patients underwent revascularization procedures on 49 hemispheres with a median follow-up of 2.6 years from surgery. Median age at surgery was 7.3 years (range 1.4-18.0 years). Thirty-three hemispheres (67.3%) underwent combined revascularization with a direct bypass and encephalomyosynangiosis, and sixteen hemispheres (32.7%) underwent indirect-only revascularization. The rate of 30-day perioperative complication was 10.2%, and the rate of postoperative clinical stroke by end of follow-up was 10.2% by hemisphere. There was a 5.7% rate of intraoperative bypass failure requiring conversion to an indirect revascularization approach. On follow-up imaging, 96.9% of direct bypasses remained patent. On multivariate analysis, higher preoperative Pediatric Stroke Outcome Measure (PSOM) scores were associated with lower rates of good clinical outcome on follow-up (unit OR 0.03; p = 0.03). Patients with age < 5.4 years had lower rates of good clinical outcome on follow-up. In this North American cohort, both combined direct/indirect and indirect only revascularization techniques were feasible. However, younger children < 5.4 years of age have worse outcomes than older children, similar to east Asian cohorts.

CRAO in Moyamoya Syndrome Associated With Southampton Hemoglobinopathy

The authors present the first case of central retinal artery occlusion (CRAO) resulting from moyamoya syndrome secondary to Southampton hemoglobinopathy. A 12-year-old Hispanic girl with a history of Southampton hemoglobinopathy with moyamoya syndrome presented with amaurosis fugax in her left eye that resolved within hours except for an inferior paracentral scotoma. She had left ophthalmic artery occlusion on magnetic resonance angiogram. Seven months later, spectral-domain optical coherence tomography showed diffuse inner retinal thinning. She was diagnosed with transient CRAO. The authors conclude that CRAO can result from moyamoya syndrome secondary to an underlying hemoglobinopathy. Multimodal imaging demonstrated residual inner retinal injury despite reperfusion. [Ophthalmic Surg Lasers Imaging Retina. 2019;50:e166-e170.].

Evaluation and treatment of children with radiation-induced cerebral vasculopathy

OBJECTIVE

Stenoocclusive cerebral vasculopathy is an infrequent delayed complication of ionizing radiation. It has been well described with photon-based radiation therapy but less so following proton-beam radiotherapy. The authors report their recent institutional experience in evaluating and treating children with radiation-induced cerebral vasculopathy.

METHODS

Eligible patients were age 21 years or younger who had a history of cranial radiation and subsequently developed vascular narrowing detected by MR arteriography that was significant enough to warrant cerebral angiography, with or without ischemic symptoms. The study period was January 2011 to March 2019.

RESULTS

Thirty-one patients met the study inclusion criteria. Their median age was 12 years, and 18 (58%) were male. Proton-beam radiation therapy was used in 20 patients (64.5%) and photon-based radiation therapy was used in 11 patients (35.5%). Patients were most commonly referred for workup as a result of incidental findings on surveillance tumor imaging (n = 23; 74.2%). Proton-beam patients had a shorter median time from radiotherapy to catheter angiography (24.1 months [IQR 16.8-35.4 months]) than patients who underwent photon-based radiation therapy (48.2 months [IQR 26.6-61.1 months]; p = 0.04). Eighteen hemispheres were revascularized in 15 patients. One surgical patient suffered a contralateral hemispheric infarct 2 weeks after revascularization; no child treated medically (aspirin) has had a stroke to date. The median follow-up duration was 29.2 months (IQR 21.8-54.0 months) from the date of the first catheter angiogram to last clinic visit.

CONCLUSIONS

All children who receive cranial radiation therapy from any source, particularly if the parasellar region was involved and the child was young at the time of treatment, require close surveillance for the development of vasculopathy. A structured and detailed evaluation is necessary to determine optimal treatment.

Side-to-Side Superficial Temporal Artery to Middle Cerebral Artery Bypass Technique: Application of Fourth Generation Bypass in a Case of Adult Moyamoya Disease

BACKGROUND

Moyamoya disease (MMD) is a rare cause of cerebral hemorrhage and ischemia. Spontaneous development of collateral supply from the external carotid artery (ECA) may limit the use of donor arteries used in standard direct bypass techniques.

OBJECTIVE

To identify the technical feasibility of side-to-side (S-S) superficial temporal artery to middle cerebral artery (STA-MCA) bypass and demonstrate the application of fourth generational bypass techniques in the treatment of MMD.

METHODS

S-S bypass was performed in order to maintain distal outflow in the donor STA. Fourth generation bypass techniques, including atypical anastomosis construction and intraluminal suturing were utilized.

RESULTS

The novel S-S STA-MCA bypass was performed, with patent flow in both recipient MCA and endogenous ECA-ICA collaterals supplied by the distal STA. Technical nuances, including proper alignment of donor vessel, tension reduction, and S-S anastomosis construction with intraluminal suturing technique are essential for successful bypass. Unique flow properties of this bypass were identified, resulting in flow augmentation to the recipient territory compared to standard end-to-side (E-S) techniques.

CONCLUSION

Fourth generational bypass techniques can be successfully applied to MMD, allowing for novel bypass construction. S-S anastomosis can result in potentially beneficial flow properties compared to standard E-S constructions.

Preservation of the Arachnoid Membrane During Encephaloduroarteriosynangiosis Reduces Postoperative Complications without Undermining the Surgical Outcome in Pediatric Moyamoya Disease

BACKGROUND

Encephaloduroarteriosynangiosis (EDAS) is a commonly used indirect revascularization operation method to treat pediatric patients with Moyamoya disease (MMD). Arachnoid dissection frequently has been performed during the EDAS operation to promote better revascularization. However, no studies have yet proven its surgical benefits. In this study, we investigated the impact of arachnoid preservation on the surgical outcome and postoperative complication by comparing pediatric patients with MMD who had the arachnoid membrane preserved during EDAS operation with those who had it dissected.

METHODS

This was a retrospective cohort study based on a single surgeon's experience at a single institution. A total of 206 pediatric patients with MMD who underwent EDAS operation at Seoul National University Children's Hospital were recruited for the study. We compared the surgical outcome and the postoperation complication rate of these 2 groups. Furthermore, risk factors for postoperative complication were analyzed.

RESULTS

The overall clinical outcome (P = 0.342) and the extent of revascularization of middle cerebral artery territories (P = 0.736) were not different between the arachnoid dissection group and the arachnoid preservation group. However, the postoperative infarction/hemorrhage rate was significantly greater in the arachnoid dissection group (P = 0.005). Arachnoid dissection (P = 0.011) and young age (<3 years old, P = 0.012) were significantly associated with increased risk of postoperative complications.

CONCLUSIONS

Arachnoid preservation may help to reduce postoperative complications without decreasing the surgical outcome of EDAS. Furthermore, factors such as the patient's age should be taken into account when treating pediatric patients with MMD.

Aspirin in childhood acute ischemic stroke: The evidence for treatment and efficacy testing

Aspirin is the most commonly prescribed antiplatelet agent worldwide, but evidence supporting its use varies by age and disease process. Despite its frequent use in childhood acute ischemic stroke prevention and management, major knowledge gaps exist about optimal pediatric aspirin use, particularly in this setting, where high-quality clinical trials are urgently needed. This review focuses upon the evidence for aspirin use in childhood acute ischemic stroke, includes a summary of aspirin pharmacology to highlight misconceptions and common clinical situations which may limit its efficacy, and discusses the techniques and potential role of laboratory monitoring of aspirin efficacy in children.

Results of more than 20 years of follow-up in pediatric patients with moyamoya disease undergoing pial synangiosis

OBJECTIVE

There are limited data on the long-term outcomes for children undergoing surgical revascularization for moyamoya disease (MMD) in North America. The authors present a series of pediatric MMD patients who underwent a standard revascularization procedure, pial synangiosis, more than 20 years previously at a single institution by a single surgical team.

METHODS

This study is a retrospective review of all patients aged 21 years or younger treated for MMD at Boston Children's Hospital who were operated on more than 20 years previously by the senior author (R.M.S.). Radiographic and operative reports, outpatient clinical records, and communications with patients and families were reviewed to document current clinical status, ability to perform daily activities, and concurrent or new medical conditions.

RESULTS

A total of 59 patients (38 female [64.4%], 21 male [35.6%]; median age at surgery 6.2 years [IQR 0.5-21 years]) were identified who were diagnosed with MMD and underwent surgical revascularization procedures more than 20 years previously. Clinically, all but 2 patients (96.6%) presented with the following symptoms alone or in combination: 43 (73%) presented with stroke, 22 (37%) with transient ischemic attack, 12 (20%) with seizures, 7 (12%) with headache, 3 (5%) with choreiform movements, and 2 (3%) with hemorrhage; MMD was incidentally detected in 2 patients (3%). Five patients had unilateral MMD at presentation, but 3 of these ultimately progressed to develop bilateral MMD after an average of 16 months; therefore, pial synangiosis was ultimately performed in a total of 116 hemispheres during the study period. Clinical follow-up was available at a median interval of 20.6 years (IQR 16.1-23.2 years). Modified Rankin Scale scores were stable or improved in 43 of 50 patients with evaluable data; 45 of 55 are currently independent. There were 6 patient deaths (10.2%; 3 due to intracranial hemorrhage, 2 due to tumor-related complications, and 1 due to pulmonary artery stenosis), 4 of whom had a history of previous cranial radiation. One patient (1.7%) experienced a late stroke. Synangiosis vessels remained patent on all available late MRI and MRA studies. Four patients reported uneventful pregnancies and vaginal deliveries years following their revascularization procedures.

CONCLUSIONS

Revascularization for MMD by pial synangiosis appears to confer protection from stroke for pediatric patients over long-term follow-up. A history of cranial radiation was present in 4 of the 6 patients who died and in the lone patient with late stroke. Most patients can expect productive, independent lives following revascularization surgery in the absence of significant preoperative neurological deficits and comorbidities.

Radial Artery Fascial Flow-Through Free Flap for Complex Cerebral Revascularization: Technical Notes and Long-Term Neurologic and Radiographic Outcomes

BACKGROUND

Surgical innovation is critical for the management of challenging cerebrovascular pathology. Flow-through free flaps are versatile composite grafts that combine viable tissue with a revascularization source. Neurosurgical experience with these flaps is limited.

OBJECTIVE

To provide an in-depth technical description of the radial artery fascial (and fasciocutaneous) flow-through free flap (RAFF and RAFCF, respectively) for complex cerebral revascularizations.

METHODS

An Institutional Review Board-approved, prospective database was retrospectively reviewed to identify patients that underwent extracranial-to-intracranial cerebral bypass with a RAFF or RAFCF. Patient demographics, underlying pathology, surgical treatment, complications, and outcomes were recorded.

RESULTS

A total of 4 patients were treated with RAFFs or RAFCFs (average age 40 ± 8.8 yr). Two patients with progressive moyamoya disease involving multiple vascular territories with predominantly anterior cerebral artery (ACA) symptoms and flow alterations underwent combined direct ACA and indirect middle cerebral artery (MCA) bypass with a RAFF. The third patient with moyamoya disease and concomitant proximal fusiform aneurysms requiring internal carotid artery sacrifice underwent dual direct ACA and MCA bypass and indirect MCA revascularization with posterior tibial artery and RAFF grafts. The fourth patient with a large MCA bifurcation aneurysm and recurrent wound complications underwent a direct MCA bypass and complex wound reconstruction using a RAFCF. Good neurologic outcomes (Glasgow Outcomes Scale score ≥4 at discharge) were achieved in all patients. There were no perioperative surgical complications, and graft patency was confirmed on long-term follow-up.

CONCLUSION

The RAFF and RAFCF are versatile grafts for complex cerebral revascularizations.

Superficial temporal artery-to-middle cerebral artery bypass in combination with indirect revascularization in moyamoya patients ≤ 3 years of age

OBJECTIVE Revascularization is indicated in the management of moyamoya disease (MMD), with options that include direct and indirect techniques. Indirect bypass is popular in young children because the diminutive caliber of donors and recipients makes direct bypass difficult. The authors reviewed a series of patients treated with direct superficial temporal artery (STA)–to–middle cerebral artery (MCA) bypass in combination with encephalomyosynangiosis (EMS) in children 3 years or younger to demonstrate feasibility and safety. METHODS A retrospective review of all surgeries for MMD over a 19-year period identified 11 procedures in 6 patients. Surgical results, angiographic outcomes, and clinical outcomes were analyzed. RESULTS Patients had a mean age of 22.4 months. The symptomatic hemisphere was revascularized first, and the contralateral hemisphere was revascularized on average 2.8 months later in 5 patients. All direct bypasses were patent postoperatively and remained patent at late follow-up (mean 4.1 years), with both STA and MCA diameters increasing significantly (n = 5, p < 0.03). At last follow-up (mean follow-up duration, 5.0 years), favorable outcomes (modified Rankin Scale scores 0–2) were observed in 5 of the 6 patients (83%), with 1 dependent patient remaining unchanged postoperatively. CONCLUSIONS Direct STA-MCA bypass in combination with EMS for MMD is feasible and safe in patients 3 years or younger, based on favorable clinical and radiological outcomes in this patient cohort. Direct bypass should be considered when immediate revascularization is needed, without the biological delay associated with indirect bypass. ABBREVIATIONS EDAS = encephaloduroarteriosynangiosis; EMS = encephalomyosynangiosis; MCA = middle cerebral artery; MMD = moyamoya disease; mRS = modified Rankin Scale; STA = superficial temporal artery; TIA = transient ischemic attack.

The management of childhood cancer survivors at risk for stroke: A Delphi survey of regional experts

BACKGROUND

Evidence is not available to guide management of childhood cancer survivors (CCS) at risk for radiation-associated cerebral vascular disease (CVD) and stroke. We propose to use a consensus-based methodology to describe the collective opinion of regional experts for the care of these patients and identify areas of controversy.

PROCEDURE

Thirty physicians from the New England region who care for CCS participated in a Delphi panel querying their management approach (imaging, laboratory tests, medications, counseling, referrals) to a CCS treated with cranial radiation formatted as five clinical scenarios (asymptomatic, small- and large-vessel CVD, transient ischemia, stroke) in three rounds of anonymous questionnaires. Consensus defined as ≥90% agreement.

RESULTS

Response rate was 100% for all three rounds. Panelists reached consensus on laboratory tests to assess stroke risk factors, stroke risk and prevention counseling, brain imaging to monitor survivors with known CVD, and acute care for stroke symptoms. Only 67% panelists agreed with MRI screening asymptomatic survivors with no history of CVD, 87% endorsed aspirin as stroke prevention for large-vessel CVD and 57% for small-vessel CVD. There was no consensus on specialty referrals. Overall, panelists practicing at large institutions and neurology subspecialists were more likely to advocate for screening, interventions, and referrals.

CONCLUSIONS

Despite lack of evidence to guide stroke prevention in CCS treated with cranial radiation, a panel of regional physicians reached consensus on managing most clinical scenarios. Controversial areas requiring further study are surveillance imaging for asymptomatic survivors, aspirin for stroke prevention, and indications for specialty referral.

Progress in moyamoya disease

Moyamoya disease is characterized by progressive stenosis or occlusion of the intracranial portion of the internal carotid artery and their proximal branches, resulting in ischemic or hemorrhagic stroke with high rate of disability and even death. So far, available treatment strategies are quite limited, and novel intervention method is being explored. This review encapsulates current advances of moyamoya disease on the aspects of epidemiology, etiology, clinical features, imaging diagnosis and treatment. In addition, we also bring forward our conjecture, which needs to be testified by future research.

Moyamoya Vasculopathy in Indian Children: Our Experience

Background:

Moyamoya vasculopathy is a chronic progressive vaso-occlusive disease affecting the distal intracranial carotid arteries and their proximal branches. It is an important cause of recurrent strokes in children. Surgical revascularization procedures are now considered as the treatment option for moyamoya vasculopathy. The data from Indian children with moyamoya vasculopathy are limited to a very few studies.

Study Design:

We analyzed the records of children with moyamoya vasculopathy treated at our tertiary care center from 2000 to 2014. Our study population included all patients (aged 0–18 years) with moyamoya disease/syndrome (MMD/MMS). The demographic data, clinical characteristics, imaging, treatment details, and surgical procedures performed were reviewed.

Results:

A total of 41 patients (females-19, males-22) were identified. Thirty-three (80.48%) had MMD and eight (19.5%) had MMS. The mean age (±standard deviation) at presentation was 6.26 ± 3.79 years (range: 6 months–14 years). Majority had ischemic events at onset; none had hemorrhagic manifestations. Twenty-eight (68.29%) patients underwent surgery (a total of 33 surgical procedures, bilateral in five and unilateral in 23) and 13 (31.7%) were managed conservatively. The median duration of follow-up was 2.2 ± 1.85 years (range: 4 months–7 years). Two/thirteen patients (15%), who were managed conservatively, had recurrent strokes as against none (0/28) in the operated patients. No mortality was observed in our cohort.

Conclusion:

We agree with previous studies that Indian patients with moyamoya vasculopathy differ from their Asian and European counterparts. The availability of expertise in revascularization surgeries in various centers should prompt surgery as an efficient and safe treatment option.

[Revascularization experience and results in ischaemic cerebrovascular disease: Moyamoya disease and carotid occlusion]

INTRODUCTION

Cerebral revascularization techniques are an indispensable tool in the current armamentarium of vascular neurosurgeons. We present revascularization surgery experience and results in both moyamoya disease and occlusive cerebral ischaemia.

PATIENTS AND METHODS

Patients with ischaemic occlusive disease and moyamoya disease who underwent microsurgical revascularization between October 2014 and September 2017 were analysed.

RESULTS

In the study period, 23 patients with occlusive ischaemic disease underwent microsurgical revascularization. Three patients presented with serious postoperative complications (2 intraparenchymal haemorrhages in the immediate postoperative period and one thrombosis of the femoral artery). All patients, except one, achieved normalization of the cerebral hemodynamic reserve (CHR) in the SPECT study. Twenty patients had a good neurological result, with no ischaemic recurrence of the revascularized territory. Among patients with moyamoya, 20 had moyamoya disease and 5 had moyamoya syndrome with unilateral involvement. Five patients were treated at paediatric age. Haemorrhagic onset occurred in 2 patients. The CHR study showed hemodynamic compromise in all patients. Cerebral SPECT at one year showed resolution of the hemodynamic failure in all patients. There have been 4 postoperative complications (acute subdural hematoma, two subdural collections and one dehiscence of the surgical wound). No patient presented with neurological worsening at 6 and 12months of follow-up.

CONCLUSIONS

Cerebral revascularization through end-to-side anastomosis between the superficial temporal artery and a cortical branch of the middle cerebral artery is an indisputable technique in the treatment of moyamoya disease and possibly in a subgroup of patients with symptomatic occlusive ischaemic cerebrovascular disease.

Intermittent Hemiplegia in a Boy with Primary Moyamoya Disease: A Case Report from Iran

Moyamoya is a rare chronic progressive occlusive cerebrovascular disease. Its manifestation varies from stroke, progressive learning impairment and transient ischemic attack to headache and seizure. There is no accepted medical treatment and surgery usually, is needed. We report here a case of 8 yr old boy referred to psychiatrist outpatient. An eight yr old boy with intermittent hemiplegia was brought to Imam Ali Clinic, Yazd, Iran in 2015 because his headache and medical problem began from 6 yr old. Stress and excitement exacerbated his condition. His first attack was at the age of 6 yr old. During attack, he had incontinence, severe headache, alogia, pallor, claudication and left hemiplegia (Left lower limb). Magnetic resonance angiography (MRA) was done and our diagnosis was moyamoya disease. Moyamoya is a mysterious disease and psychiatrists should consider it in differential diagnosis of alogia and plegia. Acute management of this disease is mainly symptomatic. Nowadays, surgery is a good choice and early diagnosis of this disease can change our patient's life.

Surgical Outcome for Moyamoya Disease: Clinical and Perfusion Computed Tomography Correlation

OBJECTIVES

To compare surgical outcome both radiologically and clinically after interventions for patients with Moyamoya disease.

METHODS

This retrospective observational study included 25 patients who were treated surgically for Moyamoya disease in the past 14 years. Clinical outcomes were analyzed by subgroups stratified by age, disease presentation, and surgical intervention. Serial postoperative brain computed tomography perfusion records were analyzed with respect to the cerebral blood flow and cerebrovascular reserve capacity (CVRC) of the middle cerebral artery territory. Changes in both the intervention (n = 23) and nonintervtion (n = 9) cerebral hemispheres were compared.

RESULTS

All children treated by synangiosis (n = 9), all adults receiving synangiosis (n = 5), and 88.9% of adults undergoing bypass (n = 9) had no neurologic deterioration, with a duration of at least 50.6 months, 85.7 months, and 27.7 months, respectively. Radiologically, CVRC improved more markedly after bypass surgery than synangiosis, particularly 12-24 months postoperatively (51.1% vs. -2.86%). The hemispheres that did not undergo intervention showed similar improvement in cerebral blood flow over time compared with the hemispheres that did undergo intervention, after surgery was performed.

CONCLUSIONS

Bypass surgery improved CVRC greater than synangiosis, which may correlate with decreased future stroke risks. The decision for bypass is to be balanced with a greater risk of postoperative neurologic deterioration in adults after this procedure. The hemisphere that did not undergo intervention also appeared to benefit from surgery performed on the contralateral brain.

Transient Intraoperative Central Diabetes Insipidus in Moyamoya Patients Undergoing Revascularization Surgery: A Mere Coincidence?

We present 2 patients with Moyamoya disease undergoing revascularization surgery who developed transient intraoperative central diabetes insipidus with spontaneous resolution in the immediate postoperative period. We speculate that patients with Moyamoya disease may be predisposed to a transient acute-on-chronic insult to the arginine vasopressin-producing portion of their hypothalamus mediated by anesthetic agents. We describe our management, discuss pertinent literature, and offer possible mechanisms of this transient insult. We hope to improve patient safety by raising awareness of this potentially catastrophic complication.