Incidence of biomarkers in high-grade gliomas and their impact on survival in a diverse SouthEast Asian cohort - a population-based study.

BACKGROUND: Gliomas consist of a heterogeneous group of tumors. This study aimed to report the incidences of O6-methylguanine-DNA-methyltransferase (MGMT) promoter methylation, 1p19q co-deletion, isocitrate dehydrogenase (IDH) gene mutations, and inactivating mutations of alpha-thalassemia/mental retardation syndrome X-linked (ATRX) in high-grade gliomas in an ethnically diverse population. METHODS: Records of patients who underwent surgery for high-grade gliomas from January 2013 to March 2017 at our institution were obtained. The patients' age, gender, ethnicity, Karnofsky Performance Scale (KPS) score, ability to perform activities of daily living (ADLs), tumor location and biomarkers status were recorded. Data were analyzed using chi-square and Mann-Whitney U tests, Kaplan-Meier estimates and log-rank test. RESULTS: 181 patients were selected (56 with grade III gliomas, 125 with grade IV gliomas). In the grade III group, 55% had MGMT promoter methylation, 41% had 1p19q co-deletion, 35% had IDH1 mutation and none had ATRX loss. In the grade IV group, 30% had MGMT promoter methylation, 2% had 1p19q co-deletion, 15% had IDH1 mutation and 8% had ATRX loss. After adjusting for effects of age, surgery and pre-operative ADL statuses, only MGMT promoter methylation was found to be significantly associated with longer overall survival time in grade III (p = 0.024) and IV patients (p = 0.006). CONCLUSIONS: The incidences of MGMT promoter methylation and IDH1 mutation were found to be comparable to globally reported rates, but those of 1p19q co-deletion and ATRX loss seemed to be lower in our cohort. MGMT promoter methylation was associated with increased overall survival in our cohort and might serve as favorable prognostic factor.

Effects of surgery on neurocognitive function in patients with glioma: a meta-analysis of immediate post-operative and long-term follow-up neurocognitive outcomes.

PURPOSE: This study aims to identify the neuropsychological tests commonly used for assessment in each neurocognitive domain, and quantify the post-operative changes in neurocognitive function in the immediate post-operation and follow-up. METHODS: With the use of the PubMed, a comprehensive search of the English literature was performed following PRISMA (Preferred Reporting Items for Systematic reviews and Meta-Analyses) guidelines. There were 1021 publications identified for screening. Standardized mean differences (SMD) in neuropsychological task performance were calculated both for immediate post-operation (up to 1 week) and follow-up (up to 6 months). RESULTS: Out of 12 studies which met the inclusion criteria, 11 studies were analyzed in this meta-analysis, with a total of 313 patients (age range 18-82, 50% males) with intracranial gliomas (45% high-grade, 55% low-grade). Complex attention, language and executive function were the most frequently tested neurocognitive domains. Surgery had a positive impact in the domains of complex attention, language, learning and memory tasks in the immediate post-operative period and sustained improvement at follow-up. In contrast, surgery was found to negatively impact performance for executive function in the immediate post-operative period with sustained decline in performance in the long term. CONCLUSIONS: This meta-analysis suggests that surgery for glioma confers a benefit for the domains of complex attention, language, learning and memory, while negatively affecting executive function, in the periods immediately after surgery and at 6 months follow-up. In addition, awake surgery seemed to confer a beneficial effect on neurocognitive functions. Future research should attempt to standardize a battery of neuropsychological tests for patients undergoing surgical resection for glioma, perhaps with a particular focus on executive function.

External Validation of Hematoma Expansion Scores in Spontaneous Intracerebral Hemorrhage in an Asian Patient Cohort.

BACKGROUND: Hematoma expansion (HE) occurs in approximately one-third of patients with intracerebral hemorrhage (ICH) and is known to be a strong predictor of neurological deterioration as well as poor functional outcome. This study aims to externally validate three risk prediction models of HE (PREDICT, 9-point, and BRAIN scores) in an Asian population. METHODS: A prospective cohort of 123 spontaneous ICH patients admitted to a tertiary hospital (certified stroke center) in Singapore was recruited. Logistic recalibrations were performed to obtain updated calibration slopes and intercepts for all models. The discrimination (c-statistic), calibration (Hosmer-Lemeshow test, le Cessie-van Houwelingen-Copas-Hosmer test, Akaike information criterion), overall performance (Brier score, R2), and clinical usefulness (decision curve analysis) of the risk prediction models were examined. RESULTS: Overall, the recalibrated PREDICT performed best among the three models in our study cohort based on the novel matrix comprising of Akaike information criterion and c-statistic. The PREDICT model had the highest R2 (0.26) and lowest Brier score (0.14). Decision curve analyses showed that recalibrated PREDICT was more clinically useful than 9-point and BRAIN models over the greatest range of threshold probabilities. The two scores (PREDICT and 9-point) which incorporated computed tomography (CT) angiography spot sign outperformed the one without (BRAIN). CONCLUSIONS: To our knowledge, this is the first study to validate HE scores, namely PREDICT, 9-Point and BRAIN, in a multi-ethnic Asian ICH patient population. The PREDICT score was the best performing model in our study cohort, based on the performance metrics employed in this study. Our findings also showed support for CT angiography spot sign as a predictor of outcome after ICH. Although the models assessed are sufficient for risk stratification, the discrimination and calibration are at best moderate and could be improved.

Incidence of Recurrent Intracerebral Hemorrhages in a Multiethnic South Asian Population.

INTRODUCTION: Spontaneous primary intracerebral hemorrhage (ICH) accounts for approximately 25% of all strokes in Singapore. Incidence of recurrent ICH is not well studied, and previous studies have reported inconsistent findings in the rate and risk factors associated with ICH recurrences. We aimed to study the incidence of recurrent ICHs in Singapore and to identify the associated risk factors as well as pattern of ICH recurrence. METHODS: A retrospective review of all consecutive admissions for intracerebral hemorrhage at the National Neuroscience Institute between January 2006 and November 2013 was performed. Imaging and computerized clinical records were reviewed. The demographic, clinical, and radiological characteristics of index and recurrent ICH were compared. Univariate analysis was performed using chi-square and Student's t-test, and logistic regression was used to analyze the predictors of ICH recurrence. RESULTS: In total, 1708 patients who survived the index ICH beyond 14 days were followed up for 6398 person-years. Sixty patients developed 68 recurrences of ICH, giving rise to an annual incidence rate of ICH recurrence of 1.1%. A history of previous ischemic stroke (P = .001) and index lobar location of ICH (P = .004) were significantly associated with the occurrence of ICH recurrences on multivariate analysis. The most common pattern on ICH recurrence was ganglionic-ganglionic (44.1%), followed by lobar-lobar (17.6%). Overall mortality of recurrent ICH was 17.6%. CONCLUSION: The average annual incidence rate of primary ICH recurrence in Singapore is 1.1%, and is associated with previous ischemic stroke and lobar location of index ICH.

Identifying risk factors of intracerebral hemorrhage stability using explainable attention model.

Segmentation of intracerebral hemorrhage (ICH) helps improve the quality of diagnosis, draft the desired treatment methods, and clinically observe the variations with healthy patients. The clinical utilization of various ICH progression scoring systems has limitations due to the systems' modest predictive value. This paper proposes a single pipeline of a multi-task model for end-to-end hemorrhage segmentation and risk estimation. We introduce a 3D spatial attention unit and integrate it into the state-of-the-art segmentation architecture, UNet, to enhance the accuracy by bootstrapping the global spatial representation. We further extract the geometric features from the segmented hemorrhage volume and fuse them with clinical features such as CT angiography (CTA) spot, Glasgow Coma Scale (GCS), and age to predict the ICH stability. Several state-of-the-art machine learning techniques such as multilayer perceptron (MLP), support vector machine (SVM), gradient boosting, and random forests are applied to train stability estimation and to compare the performances. To align clinical intuition with model learning, we determine the shapely values (SHAP) and explain the most significant features for the ICH risk scoring system. A total of 79 patients are included, of which 20 are found in critical condition. Our proposed single pipeline model achieves a segmentation accuracy of 86.3%, stability prediction accuracy of 78.3%, and precision of 82.9%; the mean square error of exact expansion rate regression is observed to be 0.46. The SHAP analysis reveals that CTA spot sign, age, solidity, location, and length of the first axis of the ICH volume are the most critical characteristics that help define the stability of the stroke lesion. We also show that integrating significant geometric features with clinical features can improve the ICH progression scoring by predicting long-term outcomes. Graphical abstract Overview of our proposed method comprising of spatial attention and feature extraction mechanisms. The architecture is trained on the input CT images, and the first step output is the predicted segmentation of the hemorrhagic region. The output is fed into a geometric feature extractor and is fused with clinical features to estimate ICH stability using a multilayer perceptron (MLP).

Longitudinal medication profile and cost savings in Parkinson's disease patients after bilateral subthalamic nucleus deep brain stimulation.

INTRODUCTION: Deep brain stimulation of the subthalamic nucleus (STN DBS) has been shown to reduce antiparkinsonian medication in Parkinson's disease. We aimed to investigate the changes in long-term medication profile with STN DBS. METHODS: Antiparkinsonian medication data for 56 patients were collected from as early as 3 years before STN DBS up to 10 years after. Cost spending on medication changes was analyzed. Mean levodopa equivalent daily dose (LEDD) was projected 10 years into the future based on preoperative data to create a comparator group wherein the patients did not undergo STN DBS. Use of neuroleptics and antidepressants was also recorded. RESULTS: LEDD requirement was significantly reduced by a mean of 31 ± 2% over 10 years after DBS, from 1049 ± 381 mg at pre-DBS baseline, to 713 ± 392 mg at 1 year post-DBS, and 712 ± 385 mg at 10 years post-DBS. This was associated with a mean reduction of 35 ± 3% in medicine cost. Modeled LEDD requirements for not having STN DBS were in the range of 1489 mg to 2721 mg at 10 years post-DBS (109-282% higher than the observed mean LEDD in DBS cohort). The proportion of patients increased from 5% before STN DBS to 14% at 10 year post-DBS for neuroleptics, and 11-23% for antidepressants. CONCLUSION: STN DBS led to LEDD reduction and antiparkinsonian medication cost savings in our South-East Asian cohort. Medication reduction with STN DBS in our cohort over the 10-year period was comparable to those reported in Western populations.

Survey on Willingness to Pay for Life-Saving Treatment, Functional Recovery, and Cosmesis in a Neuroscience Outpatient Clinic Setting in Singapore.

BACKGROUND: Neurologic disorders impose a heavy burden on healthcare in Singapore. To date, no data on the willingness to pay (WTP) for neurologic treatments has been reported in the local population. OBJECTIVES: We aimed to quantify the value of various health domains to neuroscience patients and their caregivers by comparing their WTP for different types of treatments. METHODS: A questionnaire using a mixed open-ended and closed-ended contingent valuation method was developed to elicit WTP and self-administered by 112 visitors to a neuroscience outpatient clinic. The WTP for treatments in 3 health domains (advanced restoration of function, life extension, and cosmesis) was evaluated and compared. Subgroup regression analysis was performed to investigate the impact of demographic and socioeconomic factors. RESULTS: Treatment that improved cosmesis had the highest median WTP of Singapore dollar (SGD) 35 000, followed by treatment that provided 1 year of life extension (SGD 20 000) and 1 year of advanced restored function (SGD 10 000; P < .001). Respondents with a university education were willing to pay as much as 2 to 3 times of those without across all health domains. CONCLUSION: This is the first study to provide data on how different health domains are valued by neuroscience patients and caregivers in our population. Respondents valued treatment that restored or improved their physical appearances the most. These findings could contribute to future policies on the improvement of neuroscience care.

Effects of anticoagulant and antiplatelet agents in severe traumatic brain injury in an asian population - A matched case-control study.

The use of anticoagulation and antiplatelet agents (ACAP) has steadily increased over recent years. However, the effects of ACAP on traumatic brain injuries (TBI) are not well investigated. The aim of this study was to investigate the effects of pre-injury ACAP use on clinical outcome and mortality in severe TBI. A retrospective case-control study was performed for all patients who presented with severe TBI (GCS < 8) to the National Neuroscience Institute, Singapore, between 2006 and 2009. Patients with pre-injury ACAP use were compared to matched controls. Outcome measures were mortality at 14 days and 6 months, and Glasgow Outcome Score (GOS) at 6 months using a sliding dichotomy approach. Univariate analysis was performed using Chi-square and student's t-test and logistic regression was used to model the effect of ACAP on mortality rate. Forty-five patients with pre-injury use of ACAP were compared with matched controls. The mortality at 14 days (OR = 0.5, 95% CI 0.2-1.4) and 6 months (OR = 0.7, 95% CI 0.2-1.9) were not significantly different between the 2 groups. Using the sliding dichotomy approach, there was no difference in the odds for unfavorable functional outcomes at 6 months (OR = 1.2, 95% CI 0.4-3.7). In this case-control study, the use of ACAP did not have a significant effect on mortality and adverse outcomes in patients with severe TBI. This would suggest that in severe TBI, ACAP use may not contribute significantly to the overall prognosis.

A review on microelectrode recording selection of features for machine learning in deep brain stimulation surgery for Parkinson's disease.

OBJECTIVE: This study seeks to systematically review the selection of features and algorithms for machine learning and automation in deep brain stimulation surgery (DBS) for Parkinson's disease. This will assist in consolidating current knowledge and accuracy levels to allow greater understanding and research to be performed in automating this process, which could lead to improved clinical outcomes. METHODS: A systematic literature review search was conducted for all studies that utilized machine learning and DBS in Parkinson's disease. RESULTS: Ten studies were identified from 2006 utilizing machine learning in DBS surgery for Parkinson's disease. Different combinations of both spike independent and spike dependent features have been utilized with different machine learning algorithms to attempt to delineate the subthalamic nucleus (STN) and its surrounding structures. CONCLUSION: The state-of-the-art algorithms achieve good accuracy and error rates with relatively short computing time, however, the currently achievable accuracy is not sufficiently robust enough for clinical practice. Moreover, further research is required for identifying subterritories of the STN. SIGNIFICANCE: This is a comprehensive summary of current machine learning algorithms that discriminate the STN and its adjacent structures for DBS surgery in Parkinson's disease.

Validation of Prognostic Models to Predict Early Mortality in Spontaneous Intracerebral Hemorrhage: A Cross-Sectional Evaluation of a Singapore Stroke Database.

OBJECTIVE: Numerous scores have been developed for prognostication of outcomes in intracerebral hemorrhage (ICH). Prediction models must be validated internally and externally before they are considered widely applicable. We aim to independently externally validate and compare 3 prediction models (ICH score, ICH grading scale [ICH-GS], and simplified ICH [sICH]) in our population, which has not been previously done. METHODS: We reviewed 1338 patients with spontaneous ICH consecutively admitted to the National Neuroscience Institute, Singapore, between January 2009 and November 2013. We analyzed prospectively collected data of admission characteristics (clinical, neuroimaging, and laboratory findings). All 3 scores prognosticated 30-day mortality. Validation was based on calibration, goodness-of-fit tests, and discrimination (area under receiver operating characteristic curve [AUC]). Akaike information criterion (AIC) and decision curve analysis (DCA) were used to directly compare the scores. RESULTS: All 3 models showed good calibration and both the Hosmer-Lemeshow and the le Cessie-van Houwelingen-Copas goodness-of-fit test showed P values >0.05. AUCs ranged from 0.86 to 0.90, indicating good discriminative ability, with the ICH-GS performing the best with the highest AUC, lowest AIC (849), and overall highest net benefit in the DCA. CONCLUSIONS: This study successfully independently validates the ICH score, ICH-GS, and sICH score in a large patient cohort with spontaneous ICH, which has not been previously done in this non-Western population. We recommend the use of the ICH-GS as a prognostication tool in our patients instead of the widely used ICH score.

Long-term recovery profile of patients with severe disability or in vegetative states following severe primary intracerebral hemorrhage.

PURPOSE: We conducted a single-center retrospective review to investigate the long-term recovery of patients who were severely disabled or vegetative secondary to primary intracerebral hemorrhage upon discharge from hospital from January 2009 to November 2013. METHODS: Patients were categorized into two groups based on their Glasgow outcome scale (GOS) scores at discharge, namely vegetative state (GOS 2; n = 91) and severely disabled (GOS 3; n = 278). Long-term outcomes at three years post discharge were defined as death, stable, deterioration and improvement from discharge to follow-up. RESULTS: Lower mortality (29% versus 69%) and higher neurological improvement rates at three years (33% versus 10%) were observed in the SD compared to VS group (both p = .0001). Age was a significant predictor of survival in the VS group (p = .03) and the SD group (p = .012). Age was also the only predictor of neurological improvement in the SD group (p = .01). CONCLUSIONS: Neurological status at discharge from hospital was not truly indicative of long-term prognosis for patients who were severely disabled or vegetative. Patients in both groups can potentially improve in the long term and may benefit from prolonged rehabilitation programmes to maximize their recovery potential.

Awake Craniotomy for Resection of Brain Metastases: A Systematic Review.

BACKGROUND: Surgery for brain metastases aims to reduce mass effect and achieve local control through maximizing resection. There is increasing recognition that awake craniotomy (AC) is especially relevant for resection of brain metastases in eloquent areas. This study seeks to examine the neurologic outcomes of using AC for brain metastases resection. METHODS: A systematic search for studies examining the role of AC in patients with brain metastases was conducted via PubMed without limitations on the year of publication, language, or study design, using the following search terms: (cerebral OR brain) and (metastases OR tumor) and (awake OR intraoperative OR eloquent OR supramarginal). Studies were included if patients underwent AC for resection of brain metastases and data on pre- and postoperative neurologic function were available. RESULTS: Seven studies published between 2001 and 2017 with 104 patients who underwent 107 ACs were identified. Gross total resection was achieved in 61% of patients, supramarginal resection was achieved in 32%, and subtotal resection was achieved in 7%. Immediately after operation, 73% of patients experienced no change or improvement in neurologic outcomes, whereas 27% experienced worsening. In the long term, 96% of those with postoperative worsening of function experienced improvements in neurologic function. CONCLUSIONS: Most patients experienced improvements in neurologic function immediately after AC, and most patients that experienced short-term worsening of neurologic function after the procedure showed excellent recovery. AC should be considered as a technique to optimize outcomes in brain metastases in eloquent areas.

Improving Surgical Outcome Using Diffusion Tensor Imaging Techniques in Deep Brain Stimulation.

INTRODUCTION: Recent advances in surgical imaging include the use of diffusion tensor imaging (DTI) in deep brain stimulation (DBS) and provide a detailed view of the white matter tracts and their connections which are not seen with conventional magnetic resonance imaging. Given that the efficacy of DBS depends on the precise and accurate targeting of these circuits, better surgical planning using information obtained from DTI may lead to improved surgical outcome. We aim to review the available literature to evaluate the efficacy of such a strategy. METHODS: A search of PubMed was performed to identify all articles using the search terms "(diffusion tractography OR diffusion tensor imaging OR DTI) AND (deep brain stimulation OR DBS)." Studies were included if DTI was used and clinical outcomes were reported. RESULTS: We identified 35 studies where the use of DTI in DBS was evaluated. The most studied pathology was movement disorders (17 studies), psychiatric disorders (11 studies), and pain (7 studies). The overall responder rates for tremor reduction was 70.0% (SD = 26.1%) in 69 patients, 36.5% (SD = 19.1%) for obsessive-compulsive disorder in 9 patients, 48.3% (SD = 40.0%) for depression in 40 patients, and 49.7% (SD = 35.1%) for chronic pain in 23 patients. DISCUSSION: The studies reviewed show that the use of DTI for surgical planning is feasible, provide additional information over conventional targeting methods, and can improve surgical outcome. Patients in whom the DBS electrodes were within the DTI targets experienced better outcomes than those in whom the electrodes were not. Many current studies are limited by their small sample size or retrospective nature. The use of DTI in DBS planning appears underutilized and further studies are warranted given that surgical outcome can be optimized using this non-invasive technique.

Decompressive Craniectomy in Spontaneous Intracerebral Hemorrhage: A Case-Control Study.

BACKGROUND: Decompressive craniectomy is performed to relieve intracranial pressure as an emergency procedure. There is no large study to systematically evaluate the benefit of decompressive craniectomy versus best medical therapy. This study evaluates the survival and long-term functional outcomes of decompressive craniectomy for spontaneous intracranial hemorrhage. METHODS: A total of 54 eligible patients with spontaneous supratentorial hemorrhage (median age, 55 years; interquartile range, 47-64 years) who underwent decompressive craniectomy were retrospectively matched to 72 patients managed with best medical treatment (median age, 58 years; interquartile range, 32-74 years). Glasgow Outcome Scale (GOS) scores were dichotomized into favorable and unfavorable outcomes. Survival and functional outcomes were analyzed at discharge, 3, 6, and 12 months. RESULTS: Survival in the craniectomy group was significantly higher compared with the medical treatment group at 30 days, 6, and 12 months (76%, 70%, and 70% vs. 60%, 57%, and 52% respectively; all P ≤ 0.05). There was no difference in functional outcomes at discharge, 3, 6, or 12 months after hemorrhage (all P > 0.05). Decompressive craniectomy was associated with longer hospital stay (median of 30 days vs. 7 days in the control group; P < 0.001). Hospital adverse events were more frequent in the craniectomy group than in the control group (76% vs. 33%; P < 0.001), the commonest adverse events being pneumonia and urinary tract infections. CONCLUSIONS: We showed that decompressive craniectomy significantly improved survival compared with medical treatment with lasting benefits. This improvement came at a cost of increased length of hospital stay and related adverse events. There was no improvement in functional outcome.

Models of Mortality and Morbidity in Severe Traumatic Brain Injury: An Analysis of a Singapore Neurotrauma Database.

OBJECTIVE: Current prognostic models for traumatic brain injury (TBI) are developed from diverse historical data sets. We aimed to construct a prognostication tool for patients with severe TBI, as this group would benefit most from an accurate model. METHODS: Model development was based on a cohort of 300 patients with severe TBI (Glasgow Coma Scale score ≤8) consecutively admitted to a neurosurgical intensive care unit at the National Neuroscience Institute (NNI), Singapore, between February 2006 and December 2009. We analyzed prospectively collected data of admission characteristics using univariate and multivariate logistic regressions to predict 14-day and 6-month mortality and 6-month unfavorable outcome. Comparison with Corticosteroid Randomization After Significant Head Injury (CRASH) and Mission for Prognosis and Analysis of Clinical Trials in TBI (IMPACT) models was done using Akaike information criterion. RESULTS: Two prediction models, NNI Clinical (age, Glasgow Coma Scale score, pupillary reactivity) and NNI+ (NNI Clinical model with addition of obliteration of third ventricle or basal cisterns, presence of subdural hemorrhage, hypoxia, and coagulopathy), were derived from this data set. Both models predicted well across 3 outcome measures with area under the curve values of 0.84-0.91, with adequate calibration. Comparison with CRASH and IMPACT models showed better performance by both derived models with lower Akaike information criterion and higher area under the curve values. CONCLUSIONS: Two accurate prognostic models, NNI Clinical and NNI+, were developed from our cohort of patients with severe TBI. Both models are specific to severe TBI and could be better alternatives to current available models. External validation is required to assess performance of models in a different setting.

Characterization of Pyramidal Tract Shift in High-Grade Glioma Resection.

OBJECTIVE: This study aimed to characterize pyramidal tract shift in different regions of the brain during glioma resection and its association with head position and tumor location. METHODS: From 2008-2013, 14 patients presenting at the National Neuroscience Institute with high-grade glioma (World Health Organization III or IV) underwent preoperative and intraoperative diffusion tensor imaging. A novel method of placing landmarks along the preoperative and intraoperative tracts, with anterior commissure as the origin, was used to determine pyramidal tract shift. Shift was evaluated in x (lateromedial), y (anteroposterior), and z (craniocaudal) directions for 3 brain regions: brainstem, around third and lateral ventricles, and above ventricles. Shift radius is calculated as the distance between preoperative and postoperative landmarks. RESULTS: Mean shift radius was 2.72 ± 0.55, 2.98 ± 0.53, and 4.04 ± 0.58 mm at the brainstem, third and lateral ventricles, and above the ventricles, respectively (P < 0.001). Only shift in the y direction (P < 0.03) and shift radius (P < 0.03) were significantly different among regions. Head position during surgery strongly influenced shift radius above the ventricles (P < 0.005), but tumor location had no significant effect. The z-direction shift did not differ significantly among regions. CONCLUSION: Direction of pyramidal tract shift in 3 dimensions is unpredictable; hence shift radius is a more clinical useful concept. Shift radius was largest above the ventricles and was strongly influenced by head position, with a trend for temporal lobe tumors to exhibit larger shifts.

Prevalence of Asymptomatic Unruptured Intracranial Aneurysms in a Southeast Asian Population.

BACKGROUND: The prevalence of asymptomatic unruptured intracranial aneurysms (AUIA) in a Southeast Asian population has not been previously studied. Knowing the disease burden and population at risk can assist us in making informed decisions when managing AUIAs. We aimed to determine if the local prevalence of AUIAs differed from other populations in the published literature. METHODS: Magnetic resonance angiography radiology reports and images for 4572 patients between January 2013 and January 2014 were reviewed for AUIAs. RESULTS: The overall prevalence of AUIAs was 3.5% (160/4572). It was significantly higher in women (4.5%) compared with men (2.6%) (P < 0.001). The mean aneurysm size was 3.2 ± 1.7 mm. Of the aneurysms, 88.5% (146/165) measured less than 5 mm, 9.7% (16/165) measured 5-9 mm, and 1.8% (3/165) measured more than 9 mm. Most of the aneurysms were located in the cavernous segment (72/165, 43.6%) and ophthalmic segment (34/165, 20.6%) of the internal carotid artery, followed by the middle cerebral artery (16/165, 9.7%). The posterior circulation contributed 9.1% (15/165) of the AUIAs. During the study period, 1 aneurysm ruptured and the rest of the aneurysms did not show any growth. CONCLUSIONS: In this large cohort of a Southeast Asian population, the prevalence of AUIA was 3.5%. Most of the AUIAs were less than 5 mm and did not require intervention at time of discovery and did not progress within the year of follow-up.