Prediction of cerebral infarction after bypass surgery in adult moyamoya disease: using pulsatility index on TCD

BACKGROUND

At present, the most effective treatment for symptomatic moyamoya disease (MMD) is surgery. However, the high incidence of postoperative complications is a serious problem plaguing the surgical treatment of MMD, especially the acute cerebral infarction. Decreased cerebrovascular reserve is an independent risk factor for ischemic infarction, and the pulsatility index (PI) of transcranial Doppler (TCD) is a common intuitive index for evaluating intracranial vascular compliance. However, the relationship between PI and the occurrence of ischemic stroke after operation is unclear.

OBJECTIVE

To explore whether the PI in the middle cerebral artery (MCA) could serve as a potential predictor for the occurrence of ischemic infarction after bypass surgery in MMD.

METHODS

We performed a retrospective analysis of data from 71 patients who underwent combined revascularization surgery, including superficial temporal artery-middle cerebral artery (STA-MCA) anastomosis and encephalo-duro-myo-synangiosis (EDMS). The patients were divided into two groups according to the median of ipsilateral MCA-PI before operation, low PI group (MCA-PI < 0.614) and high PI group (MCA-PI ≥ 0.614). Univariate and multivariate regression analysis were used to explore risk factors affecting the occurrence of postoperative cerebral infarction.

RESULTS

Among the 71 patients with moyamoya disease, 11 patients had cerebral infarction within one week after revascularization. Among them, 10 patients' ipsilateral MCA-PI were less than 0.614, and another one's MCA- PI is higher than 0.614. Univariate analysis showed that the lower ipsilateral MCA-PI (0.448 ± 0.109 vs. 0.637 ± 0.124; P = 0.001) and higher Suzuki stage (P = 0.025) were linked to postoperative cerebral infarction. Multivariate analysis revealed that lower ipsilateral MCA-PI was an independent risk factor for predicting postoperative cerebral infarction (adjusted OR = 14.063; 95% CI = 6.265 ~ 37.308; P = 0.009).

CONCLUSIONS

A lower PI in the ipsilateral MCA may predict the cerebral infarction after combined revascularization surgery with high specificity. And combined revascularization appears to be safer for the moyamoya patients in early stages.

Predictive Factors for Seizures after Revascularization in Patients with Moyamoya Disease

BACKGROUND

Moyamoya disease (MMD) is a rare and complex cerebrovascular disorder that is diagnosed through imaging studies, such as computed tomography or magnetic resonance imagin, which show progressive narrowing of the terminal portion of the internal carotid arteries and the development of compensatory capillary collaterals. The objective of our study was to identify and clarify the predictive factors for seizures in patients with MMD.

METHODS

From January 2019 to March 2023, a total of 102 patients with MMD were enrolled in this study. Ten patients with seizures after surgery as the main presentation were included. Patients with epilepsy were compared to those without epilepsy in terms of their clinical characteristics. Multivariable analysis was applied to determine factors linked with postoperative seizures.

RESULTS

Ten patients developed seizures after revascularization for MMD. Logistic regression analysis revealed that early seizure (odds ratio [OR], 0.068; 95% CI, 0.014-0.342; P = 0.001), cortical involvement (OR, 9.593; 95% CI, 2.256-40.783; P = 0.002), and postoperative hyperperfusion (OR, 7.417; 95% CI, 1.077-51.093; P = 0.042) were significantly associated with seizures. In a multivariate analysis, it was found that early seizures were significantly associated with a higher likelihood of experiencing seizures (OR, 5.88; 95% CI, 1.01-33.96; P = 0.048), while patients who had seizures were more likely to have cortical involvement (OR, 8.90; 95% CI, 1.55-50.96; P = 0.014) or postoperative hyperperfusion (OR, 12.44; 95% CI, 1.21-127.74; P = 0.034).

CONCLUSIONS

Epilepsy in patients with MMD link with several clinical factors. In patients with MMD who undergo bypass surgery, early seizures, cortical involvement, and postoperative hyperperfusion are significant independent predictive factors for the development of epilepsy.

Analysis on Intraoperative Electrocorticogram Characteristics for Evaluating the Risk of Postoperative Epilepsy. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2023;2023:1-4. [PMID: 38083022 DOI: 10.1109/embc40787.2023.10341027] [Citation(s) in RCA: 0] [Impact Index Per Article: 0]

Epilepsy is one of the most common complications after craniotomy, which happens suddenly and does great harm. There still lacks of effective prediction method during the operation. The main purpose of this paper is to explore the correlation between the characteristics of intraoperative electrocorticogram (ECoG) and postoperative epilepsy, and select effective features to establish a prediction model. This retrospective study uses intraoperative ECoG recordings of 144 patients with cerebrovascular diseases undergoing cerebral revascularization surgeries. The cases are divided into subtypes of ischemic and hemorrhagic. Nine types of ECoG features are designed on different frequency bands indicating clinical information, power spectrum, complexity, sequence change, and information quantity, while their changes in different surgical stages are also considered. Then statistical analysis is used to obtain features significantly related to postoperative epilepsy (p<0.05). The sparse representation method is used on these features to further screen and reduce the redundancy, and then machine learning methods are used to establish a prediction model for postoperative epilepsy. The accuracy, sensitivity and specificity of the best prediction model can achieve 0.817, 0.800 and 0.833 respectively under 5-fold cross validation.Clinical Relevance-This study explores the correlation between the characteristics of intraoperative ECoG and postoperative epilepsy, investigates the possibility to use the ECoG features and machine learning algorithms to assess the risk of postoperative epilepsy during the surgery. Further results are expected to provide reference for preventive measures to reduce the occurrence of postoperative epilepsy.

Efficacy of modified EDAS combined with a superficial temporal fascia attachment-dural reversal surgery for the precise treatment of ischemic cerebrovascular disease

Objective

To investigate the potential therapeutic benefits of Modified EDAS combined with superficial temporal fascia attachment-dural reversal surgery for the treatment of ischemic cerebrovascular disease.

Methods

Retrospective analysis was made on the clinical data of 33 patients with ischemic cerebrovascular disease, who were admitted to the Neurological Diagnosis and Treatment Center of the Second Affiliated Hospital of Xinjiang Medical University from December 2019 to June 2021. All patients were treated with Modified EDAS combined with superficial temporal fascia attachment-dural reversal surgery. At 3 months after operation, the outpatient department rechecked the patient's head CT perfusion imaging (CTP) to understand the intracranial cerebral blood flow perfusion. The DSA of the patient's head was re-examined 6 months after operation to observe the establishment of collateral circulation. The improved Rankin Rating Scale (mRS) score was used to evaluate the good prognosis rate of patients at 6 months after surgery. The mRS score ≤2 was defined as good prognosis.

Results

The preoperative cerebral blood flow (CBF), local blood flow peak time (rTTP), and local mean transit time (rMTT) of 33 patients were 28.235 ml/(100 g·min), 17.702 s, 9.796 s, respectively. At 3 months after surgery, CBF, rTTP, and rMTT were 33.743 ml/(100 g·min), 15.688, and 8.100 s, respectively, with significant differences (P &lt; 0.05). At 6 months after operation, the establishment of extracranial and extracranial collateral circulation was observed in all patients by re-examination of head DSA. At 6 months after operation, the good prognosis rate was 81.8%.

Conclusion

The Modified EDAS combined with superficial temporal fascia attachment-dural reversal surgery is safe and effective in the treatment of ischemic cerebrovascular disease, which can significantly increase the establishment of collateral circulation in the operation area and improve the prognosis of patients.

Outcomes after superficial temporal artery–middle cerebral artery anastomosis combined with multiple burr hole surgery and dural inversion synangiosis for moyamoya disease in adults

Objective

Several forms of cerebral revascularization have been carried out to treat moyamoya disease, however, the existing methods are accompanied by a variety of complications. In this study, the authors aimed to evaluate the clinical and angiographic outcomes of a new surgical procedure: superficial temporal artery–middle cerebral artery (STA-MCA) anastomosis combined with multiple burr hole (MBH) surgery and dural inversion synangiosis for the treatment of moyamoya disease in adults.

Methods

Patients treated for moyamoya disease from August 2019 to July 2021 were retrospectively reviewed. Clinical data, including perioperative complications and follow-up outcomes, were noted. Preoperative and postoperative angiograms were compared, and the diameters of the frontal branch of the superficial temporal artery (F-STA), the deep temporal artery (DTA), the distal superficial temporal artery (STA) before the bifurcation and the middle meningeal artery (MMA) were measured on preoperative and postoperative angiograms. Meanwhile, a Matsushima score was assigned from postoperative angiograms.

Results

This study included 66 patients (67 hemispheres). During the follow-up period, a median of 18 (IQR, 13–21) months, no stroke or death occurred in any of the patients. The clinical outcomes were excellent in 27 patients (40.9%), good in 34 patients (51.6%), fair in 4 patients (6.0%), and poor in 1 patient (1.5%); the overall rate of favorable clinical outcomes (excellent and good) was 92.5%. The modified Rankin Scale (mRS) score was significantly improved at follow-up (P < 0.001). There were 41 hemispheres imaged by cerebral angiography after the operation, at a median postoperative interval of 9 (IQR, 8–12) months; among them, 34 (82.9%) hemispheres had Matsushima scores of grade A and grade B. The average postoperative diameters in the STA, DTA and MMA were increased significantly in 41 hemispheres at follow-up (P < 0.001). Sixteen (24.2%) patients suffered from perioperative complications, including focal hyperperfusion syndrome (HS) in 8 (12.2%) patients, cerebral infarction in 3 (4.5%) patients (including one case accompanied by wound infection), cerebral hemorrhage in 2 (3.0%) patients, seizures in 2 (3.0%) patients, and subdural effusion in 1 (1.5%) patient.

Conclusions

The procedure of STA-MCA anastomosis combined with MBH surgery and dural inversion synangiosis may be a safe and effective treatment for adult patients with moyamoya disease.

Minimally invasive cerebral revascularization in moyamoya disease in adult patients

BACKGROUND

Moyamoya disease (MMD) affects young patients, is generally progressive, and results in strokes or cerebral hemorrhages for which medical management is not effective.

OBJECTIVE

To determine the effectiveness of surgical management with minimally invasive cerebral revascularization in MMD.

MATERIAL AND METHODS

We conducted a retrospective cohort study of patients undergoing extracranial-intracranial microsurgical revascularization surgery with mini-craniotomy, analyzing the epidemiological, clinical, neuroimaging, postoperative evolution, and complications. We describe the technique in detail. Key outcomes included graft patency, complications, and recurrence of ischemic or hemorrhagic stroke.

RESULTS

From September 2017 to December 2020, 12 brain revascularization procedures for MMD were performed in eight patients (four bilateral), and all 12 grafts were classified as patent. The main complication was contralateral cerebral infarction identified by postoperative neuroimaging in a patient without clinical symptomatology. There was no case of scalp ischemia or necrosis when performing the minimally invasive approach with linear incision.

CONCLUSIONS

The results of this study suggest that the minimally invasive extracranial-intracranial cerebral revascularization procedure for MMD in adults is effective, with graft patency in all cases and minimal morbidity.

Clinical Management of Moyamoya Patients

Moyamoya angiopathy (MMA) is a peculiar cerebrovascular condition characterized by progressive steno-occlusion of the terminal part of the internal carotid arteries (ICAs) and their proximal branches, associated with the development of a network of fragile collateral vessels at the base of the brain. The diagnosis is essentially made by radiological angiographic techniques. MMA is often idiopathic (moyamoya disease-MMD); conversely, it can be associated with acquired or hereditary conditions (moyamoya Syndrome-MMS); however, the pathophysiology underlying either MMD or MMS has not been fully elucidated to date, and this poor knowledge reflects uncertainties and heterogeneity in patient management. MMD and MMS also have similar clinical expressions, including, above all, ischemic and hemorrhagic strokes, then headaches, seizures, cognitive impairment, and movement disorders. The available treatment strategies are currently shared between idiopathic MMD and MMS, including pharmacological and surgical stroke prevention treatments and symptomatic drugs. No pharmacological treatment able to reverse the progressive disappearance of the ICAs has been found to date in both idiopathic and syndromic cases. Antithrombotic agents are usually prescribed in ischemic MMA, although the coexisting hemorrhagic risk should be considered. Surgical revascularization techniques, which are currently the best available treatment in symptomatic MMA, are associated with good long-term outcomes and reduced ischemic and hemorrhagic risks. Given the lack of dedicated randomized clinical trials, current treatment is mainly based on observational studies and physicians’ and surgeons’ expertise.

Use of a panel of four microRNAs in CSF as a predicted biomarker for postoperative neoangiogenesis in moyamoya disease

INTRODUCTION AND AIMS

At present, the treatment for moyamoya disease (MMD) primarily consists of combined direct and indirect bypass surgery. Nevertheless, more than half of indirect bypass surgeries fail to develop good collaterals from the dura and temporal muscle. This study aimed to investigate whether microRNAs (miRNAs) in cerebrospinal fluid (CSF) could serve as biomarkers for the prediction of postoperative collateral formation.

METHODS

Moyamoya disease patients with indirect bypass surgery were divided into angiogenesis and non-angiogenesis groups, CSF was obtained, and miRNA sequencing was performed using the CSF. Candidate miRNAs were filtered and subsequently verified through qRT-PCR. The diagnostic utility of these differential miRNAs was investigated by using receiver operating characteristic (ROC) curve analysis. Finally, the potential biological processes and signaling pathways associated with candidate miRNAs were analyzed using R software.

RESULTS

The expression levels of four miRNAs (miR-92a-3p, miR-486-3p, miR-25-3p, and miR-155-5p) were significantly increased in the angiogenesis group. By combining these four miRNAs (area under the curve [AUC] =0.970), we established an accurate predictive model of collateral circulation after indirect bypass surgery in MMD patients. GO and KEGG analyses demonstrated a high correlation with biological processes and signaling pathways related to angiogenesis.

CONCLUSION

The 4-miRNA signature is a good model to predict angiogenesis after indirect bypass surgery and help the surgeon to select a appreciate bypass strategy.

Postoperative incidence of seizure and cerebral infarction in pediatric patients with epileptic type moyamoya disease: a meta-analysis of single rate

Background

Surgery is a conventional mature treatment for moyamoya disease (MMD). However, whether surgery is also an effective therapy for epileptic type MMD has seldom been investigated systematically. The study aims to summarize the pooled postoperative incidence of seizure and cerebral infarction in pediatric patients with epileptic type moyamoya disease.

Method

The study was a systematic review and critical appraisal with a meta-analysis of cohort studies, both prospective and retrospective. Studies were identified by a computerized search of PubMed, Embase, Web of Science, Wanfang, and CNKI databases. In a literature search, a total of 7 cohort studies were identified. The I²statistic was used to quantify heterogeneity. A fixed-effect model was used to synthesize the results. The linear regression test of funnel plot asymmetry was used to estimate the potential publication bias.

Results

The pooled estimated postoperative incidence of seizure in pediatric patients with epileptic type moyamoya disease was 23.44%. The pooled estimated postoperative incidence of cerebral infarction in pediatric patients with epileptic type moyamoya disease was 9.12%. Low substantial heterogeneity and potential publication bias were present.

Conclusions

Evidence from this study suggests that the postoperative incidence of seizure and cerebral infarction is relatively low. Surgery is an effective and secure therapy for pediatric patients with epileptic type moyamoya disease.

Preventive Effect of Bypass Surgery on Rebleeding in Patients with Hemorrhagic Twiglike Middle Cerebral Artery

BACKGROUND

Aplastic or twiglike middle cerebral artery (Ap/T-MCA) is a rare cerebrovascular anomaly correlated to stroke. The most common characteristic of the disease is intracerebral hemorrhage. However, treatment measures that can prevent rebleeding have not yet been established.

OBJECTIVE

We sought to validate whether extracranial-intracranial (EC-IC) bypass is effective in preventing recurrent intracerebral hemorrhage in patients with Ap/T-MCA.

METHODS

Ap/T-MCA was defined on the basis of the following criteria: 1) M1 occlusion with plexiform vessels, 2) unilateral MCA involvement without progression to the contralateral side, 3) no significant stenosis in the M2 segment, and 4) no stenoocclusive lesions in other intracranial major arteries. The clinical features, surgical procedures, radiologic changes, and treatment outcomes of patients with Ap/T-MCA who presented with ipsilateral intracerebral hemorrhage at our institution from April 2004 to December 2019 were retrospectively reviewed.

RESULTS

Seven patients fulfilled the criteria for hemorrhagic Ap/T-MCA. Female preponderance was observed, and the mean age at the time of onset was 38 (range: 28-47) years. Three patients presented with pure intraventricular hemorrhage and 4 with intraparenchymal hemorrhage. Of the 4 patients, 2 had intraventricular extension. All patients underwent EC-IC bypass and did not present with stroke during the follow-up period (median: 36 [range: 5-140] months). Follow-up magnetic resonance imaging revealed regression of the twiglike vessels or periventricular choroidal anastomosis within 1 year after surgery in all patients.

CONCLUSIONS

EC-IC bypass may be a treatment option that can prevent rebleeding in patients with hemorrhagic Ap/T-MCA.

Large Craniotomy Increases the Risk of Minor Perioperative Complications in Revascularization Surgery for Moyamoya Disease

OBJECTIVE

Larger craniotomy is expected to increase blood flow over a wider range after indirect revascularization. However, the optimal size of craniotomy has not been established. In this study perioperative complications in revascularization surgery for moyamoya disease are evaluated, focusing on craniotomy size.

METHODS

We retrospectively analyzed 87 hemispheres in 65 patients with moyamoya disease who had undergone revascularization surgery. Areas and types of craniotomy were classified as 1-piece craniotomy in the middle cerebral artery (MCA) territory (1-piece group) in 54 hemispheres (mean area of craniotomy, 40.6 ± 13.5 cm²); 2-piece craniotomy in the MCA territory with anterior cerebral artery (ACA) territory (2-piece group) in 16 hemispheres (mean area of craniotomy, 55.4 ± 12.0 cm²); and 1-piece craniotomy in both MCA and ACA territories (large group) in 17 hemispheres (mean area of craniotomy, 84.2 ± 11.0 cm²). Perioperative complication rates in each craniotomy group were analyzed.

RESULTS

Perioperative complications occurred in 45 hemispheres (52%). Transient, moderate, and severe complications occurred in 38 hemispheres, 3 hemispheres, and 4 hemispheres, respectively. Complication rates in the 1-piece, 2-piece, and large groups were 41%, 63%, and 76%, respectively. Large craniotomy was associated with a significantly higher frequency of complications (P = 0.01). However, no significant difference was found among groups when limiting analysis to moderate and severe complications. Multivariate analysis showed large craniotomy as the only factor independently related to complications (odds ratio, 2.93; 95% confidence interval, 1.08-7.92; P = 0.034).

CONCLUSIONS

Large craniotomy is associated with more frequent perioperative complications, especially transient symptoms.

Electroencephalographic features in pediatric patients with moyamoya disease in China

Background

Moyamoya disease (MMD) is a relatively important and common disease, especially in East Asian children. There are few reports about EEG in children with MMD in China till now. This study is aimed to analyze the electroencephalographic features of MMD in pediatric patients in China preliminarily.

Methods

Pediatric patients with MMD who were hospitalized in Peking University International Hospital and Beijing Tiantan Hospital from January 2016 to December 2018 were collected. Clinical and electroencephalography (EEG) findings were analyzed retrospectively.

Results

A total of 110 pediatric patients with MMD were involved, and 17 (15.5%) cases had a history of seizure or epilepsy. Ischemic stroke was associated with a 1.62-fold relative risk of seizure. A subset of 15 patients with complete EEG data was identified. Indications for EEG in patients with MMD included limb shaking, unilateral weakness, or generalized convulsion. Abnormal EEG was seen in 14 (93.3%) cases, with the most common findings being focal slowing 12 (80.0%), followed by epileptiform discharge 10 (66.7%), and diffuse slowing 9 (60.0%). “Re-build up” phenomenon on EEG was observed in one patient.

Conclusions

Seizure and abnormal background activity or epileptiform discharge on EEG were common in pediatric patients with MMD. EEG may play a role in differential diagnosis among the transient neurological events in MMD such as transient ischemic attack and seizure.

Cerebral Hyperperfusion Syndrome After Revascularization Surgery in Patients with Moyamoya Disease: Systematic Review and Meta-Analysis

BACKGROUND

Cerebral hyperperfusion syndrome (CHS) after bypass surgery is known as a complication of moyamoya disease (MMD). However, the incidence of CHS has not been accurately reported, and there is no consensus on related risk factors.

OBJECTIVE

To evaluate the incidence and characteristics of CHS in patients with MMD after revascularization surgery via meta-analysis.

METHODS

Relevant cohort studies were retrieved through a literature search of PubMed, Embase, and Ovid until December 1, 2018. Eligible studies were identified per search criteria. A systematic review and meta-analysis were used to assess the CHS total incidence, incidence in pediatric patients with MMD and adult patients with MMD, incidence for direct and combined bypass surgery, progress rate, and proportion of each symptom (including transient neurologic deficits [TNDs], hemorrhage, and seizure).

RESULTS

A total of 27 cohort studies with 2225 patients were included in this meta-analysis. The weighted proportions per random-effects model were 16.5% (range, 11.3%-22.3%) for CHS total incidence, 3.8% (range, 0.3%-9.6%) for pediatric patients with MMD, 19.9% (range, 11.7%-29.4%) for adult patients with MMD, 15.4% (range, 5.4%-28.8%) for direct bypass surgery, and 15.2% (range, 8.4%-23.2%) for combined bypass surgery. Progress rate was 39.5% (range, 28.7%-50.8%). The most common CHS-related symptom was TNDs (70.2%; range, 56.3%-82.7%), followed by hemorrhage (15.0%; range, 5.5%-26.9%) and seizure (5.3%; range, 0.6%-12.9%).

CONCLUSIONS

CHS is a common complication after revascularization surgery in MMD. It is more frequently seen in adult patients. The most common CHS-related symptom was TNDs, followed by hemorrhage and seizure.

Angiographic and clinical outcomes of non-patent anastomosis after bypass surgery in adult moyamoya disease

BACKGROUND

The clinical and radiologic outcomes of symptomatic adult moyamoya disease (MMD) patients who have an occluded anastomosis immediately after bypass surgery are poorly studied. The clinical and angiographic outcomes of non-patent anastomosis in symptomatic adult MMD patients were retrospectively reviewed.

METHODS

From August 2011 to November 2016, 31 revascularization surgeries, consisting of direct and indirect bypass, were performed on 29 adult MMD patients. Primary outcomes were evaluated based on the frequency of transient ischaemic attack (TIA) incidence and the recurrence of cerebral infarction and were assessed as improvement or worsening.

RESULTS

Among 31 cases, computed tomography angiography (CTA) on the first day after surgery showed patent anastomosis in 20 hemispheres and non-patent anastomosis in 11 hemispheres. Follow-up conventional angiographies showed spontaneous recanalization of non-patent anastomosis in all occlusion cases. The incidence of TIA decreased in both the non-patent and the patent groups. Two newly developed cerebral infarctions were observed, which occurred in the patent group. Patients in the non-patent group also showed clinical improvement after surgery (p = 0.04), and no significant relationship was found between immediate postoperative patency and the primary outcome (p = 0.53).

CONCLUSIONS

In our series, regardless of patency immediately after bypass surgery, delayed recanalization and clinical improvement can be expected after bypass surgery for adult MMD.

Single Vessel Double Anastomosis for Flow Augmentation – A Novel Technique for Direct Extracranial to Intracranial Bypass Surgery

BACKGROUND

A double anastomosis using a single superficial temporal artery (STA) donor branch for both a proximal side-to-side (S2S) and a distal end-to-side anastomosis is a novel direct bypass technique for use in selected patients necessitating flow augmentation.

OBJECTIVE

To describe the single-vessel double anastomosis (SVDA) technique, including its indications, advantages, and limitations, in addition to reporting our cases series of patients who underwent a SVDA bypass surgery.

METHODS

Patients undergoing a SVDA bypass at a single institution between January 2010 and February 2016 were retrospectively reviewed. Intraoperative flow data was collected, including STA cut-flow, bypass flows, and cut flow index (CFI). Bypass patency was assessed by cerebral angiography and quantitative magnetic resonance angiography with noninvasive optimal vessel analysis. Adverse events occurring during the hospital stay and clinical status at last follow up was recorded.

RESULTS

Seven patients underwent SVDA bypass. Mean follow-up was 14.5 mo. Initial CFI for the S2S bypasses averaged 0.56 ± 0.25 and CFI after the SVDA averaged 1.15 ± 0.24. There was a statistically significant average difference in CFI before and after the SVDA bypass (p < .013). Thirteen bypasses (93%) were patent postoperatively, and remained patent at last follow up. Four patients experienced various postoperative complications. None of the patients had a new stroke since hospital discharge.

CONCLUSION

SVDA is a novel technique that can be advantageous for selected cases of extracranial-to-intracranial bypass. Expertise in bypass procedures is a necessary prerequisite. Graft patency rates and complications appear comparable to other bypass techniques.

Progress on Complications of Direct Bypass for Moyamoya Disease

Moyamoya disease (MMD) involves progressive occlusion of the intracranial internal carotid artery resulting in formation of moyamoya-like vessels at the base of the brain. It can be characterized by hemorrhage or ischemia. Direct vascular bypass is the main and most effective treatment of MMD. However, patients with MMD differ from those with normal cerebral vessels. MMD patients have unstable intracranial artery hemodynamics and a poor blood flow reserve; therefore, during the direct bypass of superficial temporal artery (STA)-middle cerebral artery (MCA) anastomosis, perioperative risk factors and anesthesia can affect the hemodynamics of these patients. When brain tissue cannot tolerate a high blood flow rate, it becomes prone to hyperperfusion syndrome, which leads to neurological function defects and can even cause intracranial hemorrhage in severe cases. The brain tissue is prone to infarction when hemodynamic equilibrium is affected. In addition, bypass vessels become susceptible to occlusion or atrophy when blood resistance increases. Even compression of the temporalis affects bypass vessels. Because the STA is used in MMD surgery, the scalp becomes ischemic and is likely to develop necrosis and infection. These complications of MMD surgery are difficult to manage and are not well understood. To date, no systematic studies of the complications that occur after direct bypass in MMD have been performed, and reported complications are hidden among various case studies; therefore, this paper presents a review and summary of the literature in PubMed on the complications of direct bypass in MMD.

Predictive factors for epilepsy in moyamoya disease

BACKGROUND

Epilepsy cannot always be recognized in patients with moyamoya disease. In this report, the clinical features of patients with epilepsy were evaluated for assessing the predictive factors of epilepsy in moyamoya disease.

METHODS

A total of 64 consecutive patients with moyamoya disease were included in this study. During their follow-up periods, 7 patients were diagnosed with epilepsy. Then, the patients with epilepsy were compared with the patients without epilepsy regarding their clinical features.

RESULTS

Analysis of patient background characteristics revealed a significantly higher incidence of epilepsy in patients with high modified Rankin Scale (mRS) scores, high cerebrovascular attack scores, onset age of 3 years or less, early seizures, cortical involvement, stroke subtype, and diffuse brain atrophy. A logistic analysis of epilepsy data revealed significant differences between the 2 groups in mRS score, cerebrovascular attack score, onset age 3 years or less, early seizure, cortical involvement, stroke subtype, and diffuse brain atrophy. Of these, significant differences were noted in 3 items (mRS score, early seizure, and diffuse brain atrophy) on multivariate analysis. These 3 items were selected as the basis of our new moyamoya disease epilepsy risk scale (MDERS), which we then evaluated. The cutoff value estimated by the receiver operating characteristic curve was set at 1 (sensitivity, .857; specificity, .825) or 2 (sensitivity, .571; specificity, 1.000).

CONCLUSIONS

Epilepsy in moyamoya disease is associated with clinical factors and is not an independent category. For prediction of epilepsy in moyamoya disease, MDERS is a simple and convenient assessment scale.

Electroencephalographic features of moyamoya in adults

OBJECTIVE

Electroencephalography is useful for evaluating transient neurological events in the setting of moyamoya disease.

METHODS

EEG findings of adults with moyamoya seen at a large moyamoya referral center are summarized. Patients were identified by retrospective chart review.

RESULTS

EEGs were ordered after cerebral revascularization for altered mental status, aphasia, limb shaking, or facial twitching. Among the study population of 103 patients having EEGs, 24% of adults with moyamoya had a history of clinical seizures. Ischemic or hemorrhagic strokes were associated with a twofold relative risk of seizures. Overall, 90% of EEGs were abnormal, most commonly focally (78%), or diffusely slow (68%). Epileptiform EEG discharges were seen in 24%. Whereas hemispheres with an ischemic stroke had a 19% risk of epileptiform discharges and an 8% risk of seizures on EEG, hemispheres with hemorrhagic stroke had a 35% risk of epileptiform discharges and 19% risk of seizures on EEG. Focal amplitude attenuation was seen in 19%, breach rhythm in 15%, rhythmic delta in 14%, and electrographic seizures in 12%.

CONCLUSIONS

Seizures and epileptiform EEG changes are common in patients with moyamoya disease.

SIGNIFICANCE

Transient events in patients with moyamoya can result from seizures as well as ischemia.