Image-based assessment of natural killer cell activity against glioblastoma stem cells.

Glioblastoma (GBM) poses a significant challenge in oncology and stands as the most aggressive form of brain cancer. A primary contributor to its relentless nature is the stem-like cancer cells, called glioblastoma stem cells (GSCs). GSCs have the capacity for self-renewal and tumorigenesis, leading to frequent GBM recurrences and complicating treatment modalities. While natural killer (NK) cells exhibit potential in targeting and eliminating stem-like cancer cells, their efficacy within the GBM microenvironment is limited due to constrained infiltration and function. To address this limitation, novel investigations focusing on boosting NK cell activity against GSCs are imperative. This study presents two streamlined image-based assays assessing NK cell migration and cytotoxicity towards GSCs. It details protocols and explores the strengths and limitations of these methods. These assays could aid in identifying novel targets to enhance NK cell activity towards GSCs, facilitating the development of NK cell-based immunotherapy for improved GBM treatment.

Which battering interventions work? An updated Meta-analytic review of intimate partner violence treatment outcome research.

This meta-analytic review is an update to the first meta-analysis of battering interventions (Babcock et al., 2004) and includes 59 studies that evaluated treatment efficacy for domestically violent men and women. The outcome literature of controlled quasi-experimental and experimental studies was reviewed to test the relative impact of Duluth, cognitive-behavioral therapy (CBT), and novel types of treatment on subsequent recidivism of violence. The first model examines studies comparing interventions to no treatment control conditions. The second model compares novel interventions to treatment as usual (i.e., the Duluth curriculum). Study design and type of treatment were tested as moderators in both models. Consistent with previous meta-analyses, effect sizes were in the small range, smaller in true experiments as compared to quasi-experimental designs when recidivism was based on partner or police reports. However, new experiments comparing novel treatments to the Duluth curriculum reveal effect sizes comparable to when comparing novel interventions to an untreated comparison group. Novel interventions, including Acceptance and Commitment Therapy and Circles of Peace had the largest effect sizes when put head-to-head with Duluth control groups. Future research directions include testing moderators and mechanisms of change of the battering interventions that work. Implications for evidence-based practice in criminal justice include broader implementation and continued testing of these novel interventions with demonstrated efficacy in stopping intimate partner violence.

Developmentally Unique Cerebellar Processing Prioritizes Self- over Other-Generated Movements.

Animals must distinguish the sensory consequences of self-generated movements (reafference) from those of other-generated movements (exafference). Only self-generated movements entail the production of motor copies (i.e., corollary discharges), which are compared with reafference in the cerebellum to compute predictive or internal models of movement. Internal models emerge gradually over the first three postnatal weeks in rats through a process that is not yet fully understood. Previously, we demonstrated in postnatal day (P) 8 and P12 rats that precerebellar nuclei convey corollary discharge and reafference to the cerebellum during active (REM) sleep when pups produce limb twitches. Here, recording from a deep cerebellar nucleus (interpositus, IP) in P12 rats of both sexes, we compared reafferent and exafferent responses with twitches and limb stimulations, respectively. As expected, most IP units showed robust responses to twitches. However, in contrast with other sensory structures throughout the brain, relatively few IP units showed exafferent responses. Upon finding that exafferent responses occurred in pups under urethane anesthesia, we hypothesized that urethane inhibits cerebellar cortical cells, thereby disinhibiting exafferent responses in IP. In support of this hypothesis, ablating cortical tissue dorsal to IP mimicked the effects of urethane on exafference. Finally, the results suggest that twitch-related corollary discharge and reafference are conveyed simultaneously and in parallel to cerebellar cortex and IP. Based on these results, we propose that twitches provide opportunities for the nascent cerebellum to integrate somatotopically organized corollary discharge and reafference, thereby enabling the development of closed-loop circuits and, subsequently, internal models.

Blood-Brain Barrier Disruption for the Treatment of Primary Brain Tumors: Advances in the Past Half-Decade.

PURPOSE OF REVIEW: To review relevant advances in the past half-decade in the treatment of primary brain tumors via modification of blood-brain barrier (BBB) permeability. RECENT FINDINGS: BBB disruption is becoming increasingly common in the treatment of primary brain tumors. Use of mannitol in BBB disruption for targeted delivery of chemotherapeutics via superselective intra-arterial cerebral infusion (SIACI) is the most utilized strategy to modify the BBB. Mannitol is used in conjunction with chemotherapeutics, oligonucleotides, and other active agents. Convection-enhanced delivery has become an attractive option for therapeutic delivery while bypassing the BBB. Other technologic innovations include laser interstitial thermal therapy (LITT) and focused ultrasound (FUS) which have emerged as prime modalities to directly target tumors and cause significant local BBB disruption. In the past 5 years, interest has significantly increased in studying modalities to disrupt the BBB in primary brain tumors to enhance treatment responses and improve clinical outcomes.

A Decade of Global Skull Base Researchers: Gender Data from over 2,700 Abstract Authors in the Journal of Neurological Surgery Part B: Skull Base.

Objective The North American Skull Base Society (NASBS) annual conference brings together skull base researchers from surgical and nonsurgical fields. Our objective was to quantify the contributions of the authors by gender, who presented their work at NASBS and were subsequently published in the Journal of Neurological Surgery Part B: Skull Base . Methods Oral and poster abstracts presented at the NASBS annual meeting from January 1, 2011 to December 31, 2020 were extracted from the Journal of Neurological Surgery Part B: Skull Base. The genderize.io Web application programming interface was utilized to determine authorship gender. A minority of first and last authors had departmental affiliations listed; a subgroup analysis was performed of these authors. Results Female gender was assigned to 498 (17.8%) of the 2,798 first authors and 269 (9.7%) of the 2,762 last authors. Female authorship has consistently increased over the last decade. Representation was higher in otolaryngology (23.3% of first authors, 12.1% of last authors; p = 0.018) than neurosurgery (13.5% of first authors, 4.3% of last authors; p = 0.004). Female researchers were not less likely than their male counterparts to receive prestigious oral presentations. Of the 52 total countries represented, 20 (38.5%) had at least one female first author. Representation varied dramatically between countries. Conclusion The NASBS' efforts have undoubtedly contributed to these impressive strides toward gender parity. More work is needed to ensure that the best and the brightest, regardless of background, continue to contribute to skull base surgery research.

A Decade of Global Skull Base Researchers: Authorship Trends from 3,295 Abstracts in the Journal of Neurological Surgery Part B: Skull Base.

Objective The North American Skull Base Society (NASBS) multidisciplinary annual conference hosts skull base researchers from across the globe. We hypothesized that the work presented at the NASBS annual conference would reveal diverse authorship teams in terms of specialty and geography. Methods In this retrospective review, abstracts presented at the NASBS annual meeting and subsequently published in the Journal of Neurological Surgery Part B: Skull Base between 01/01/2011 and 12/31/2020 were collected. Variables extracted included year, type of presentation, and author names and affiliations. Statistical analyses were performed with SPSS V23.0 with p -values less than 0.05 considered significant. Geographic heat maps were created to assess author distribution, and a network analysis was performed to display authorship collaboration between geographic regions. Results Of 3,312 published abstracts, 731 (22.1%) had an author with an affiliation outside of the United States. Fifty-seven distinct countries were represented. Three-hundred twenty-four abstracts (9.8%) had authorship teams representing at least 2 different countries. The top five US states by abstract representation were Pennsylvania, California, New York, Ohio, and Minnesota. A majority of authors reported neurosurgery affiliations (56.7% first authors, 53.2% last authors), closely followed by otolaryngology (39.1% first authors, 41.5% last authors). No solo authors and very few (3.3%) of the first authors reported a departmental affiliation outside of otolaryngology or neurosurgery. Conclusions Authors from many countries disseminate their work through poster and oral presentations at the NASBS annual meeting. Ten percent of abstracts were the product of international collaboration. Most authors were affiliated with a neurosurgery or otolaryngology department.

Developmentally unique cerebellar processing prioritizes self-over other-generated movements.

Animals must distinguish the sensory consequences of self-generated movements (reafference) from those of other-generated movements (exafference). Only self-generated movements entail the production of motor copies (i.e., corollary discharges), which are compared with reafference in the cerebellum to compute predictive or internal models of movement. Internal models emerge gradually over the first three postnatal weeks in rats through a process that is not yet fully understood. Previously, we demonstrated in postnatal day (P) P8 and P12 rats that precerebellar nuclei convey corollary discharge and reafference to the cerebellum during active (REM) sleep when pups produce limb twitches. Here, recording from a deep cerebellar nucleus (interpositus, IP) in P12 rats of both sexes, we compared reafferent and exafferent responses to twitches and limb stimulations, respectively. As expected, most IP units showed robust responses to twitches. However, in contrast with other sensory structures throughout the brain, relatively few IP units showed exafferent responses. Upon finding that exafferent responses occurred in pups under urethane anesthesia, we hypothesized that urethane inhibits cerebellar cortical cells, thereby disinhibiting exafferent responses in IP. In support of this hypothesis, ablating cortical tissue dorsal to IP mimicked the effects of urethane on exafference. Finally, the results suggest that twitch-related corollary discharge and reafference are conveyed simultaneously and in parallel to cerebellar cortex and IP. Based on these results, we propose that twitches provide opportunities for the nascent cerebellum to integrate somatotopically organized corollary discharge and reafference, thereby enabling the development of closed-loop circuits and, subsequently, internal models.

Predictors of Surgical Outcomes in Patients with Abducens Nerve Schwannoma: A Comprehensive Systematic Review and a Case Report.

BACKGROUND: Abducens nerve (AN) schwannomas are extremely rare tumors. Clinical characteristics and factors that influence postoperative outcomes are not well defined. OBJECTIVE: To characterize clinical features of AN schwannomas and predictors of surgical outcomes. METHODS: PRISMA-guided systematic review of the literature on AN schwannomas was performed. Subsequently, univariate and multivariate regression analyses were performed to identify the predictive value of variables that influence postoperative outcomes. RESULTS: A total of 42 studies with 55 patients were evaluated. The mean age at presentation was 43.9 ± 14.6 years. The most common presenting symptom was cranial nerve VI palsy (69.1%). Cavernous sinus (49.1%) and prepontine cistern (36.3%) were the most commonly involved locations. Complete recovery after surgery was seen in 36.3% at a median follow-up of 28.4 ± 25.8 months. Preoperative AN palsy (P < 0.001), suboccipital approach (P = 0.007), and subtotal resection of tumor (P = 0.044) were significant protective factors for postoperative complications. Prepontine location and postoperative complications were poor prognostic indicators of AN recovery (odds ratio [OR], 0.10, P = 0.030 and OR, 0.10, P = 0.028, respectively). Subtotal resection was significantly correlated with higher odds of AN recovery (OR, 6.06; P = 0.040). CONCLUSIONS: AN schwannomas are rare but serious tumors that can cause significant morbidity, with only approximately one third of patients showing complete recovery after surgery. The suboccipital approach was a protective factor for postoperative complications, especially when combined with subtotal resection. Knowledge of these factors along with tumor characteristics helps optimize surgical planning and preoperative counseling.

Hope and anxiety.

Anxiety-related disorders continue to be one of the most prevalent and burdensome psychiatric disorders. Research has examined resilience factors, such as hope, that can build resilience toward or mitigate the impact of anxiety disorders. The following review provides a summary of hope as a factor of resilience as well as a mechanism of change in reducing levels of anxiety. First, hope and anxiety are conceptualized as future-oriented traits. Then, hope as a source of resilience against trait anxiety is discussed. The article then discusses the moderate, indirect relationship between hope and general as well as specific forms of anxiety before providing empirical support for hope as a mechanism of change in the reduction of anxiety. Finally, considerations for future study of hope and anxiety are discussed.

Factor structure of the Impact of Events Scale-Revised in Latin American young adults.

OBJECTIVE: More than 550 million people speak Spanish and, yet, psychometric data on psychological instruments in Spanish lags. Given evidence of significant traumatic exposure and distress among Spanish speakers, the aim of the current study was to examine the factor structure of the Impact of Events Scale-Revised (IES-R), in a large sample of Spanish-speaking adults. METHOD: Participants (n = 725) were university students living in Latin America (M = 21.02; SD = 3.12). Most were born in Mexico (77.6%) and the next largest subgroup was from Ecuador (18.9%). Respondents completed the 22-item IES-R. RESULTS: The IES-R mean score was 20.08 (SD = 21.34) and 26.6% of the sample met the cutoff score for clinically significant symptoms. Regarding factor structure, eight different factor structures that have demonstrated a good fit in the extant literature were examined. The one-factor model demonstrated an acceptable fit, χ²(209) = 839.13, p < .0001; root-mean-square error (RMSEA) = 0.06, 95% confidence interval (CI) [0.06, 0.07]; comparative fit index (CFI) = 0.91, Tucker-Lewis index (TLI) = 0.90. The two-factor model demonstrated good fit, χ²(208) = 746.70, p < .0001; RMSEA = 0.06, 95% CI [0.05, 0.06]; CFI = 0.92, TLI = 0.91, and nested model comparisons of the two-factor and one-factor models using the chi-square difference test supported the two-factor model. CONCLUSIONS: The most parsimonious of the multifactor models, a two-factor model with Avoidance symptoms as one factor and Intrusions and Hyperarousal combined into a second may be of greatest use for this particular version of the IES-R. The current research demonstrates strong psychometric support for Intrusion/Hyperarousal and Avoidance subscales when measuring traumatic stress in Spanish speakers and underscores the need for culturally and contextually sensitive assessment in this population, in which posttraumatic stress is prevalent. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Hope, optimism, and self-efficacy predicting mental health and illness in a community sample exposed to Hurricane Harvey.

In 2017, Hurricane Harvey flooded more than 300,000 buildings causing an estimated $125 billion in damages and resulting in 68 deaths (National Hurricane Center). This actual or threatened loss of life and physical harm led many to report negative effects on mental well-being and greater mental illness. However, many individuals have been able to experience similar adverse events without a significant negative impact on their mental health and well-being. Positive thinking factors such as hope, optimism, and self-efficacy have been proposed as protective factors in the face of difficult life events. Hope, optimism, and self-efficacy are related but distinct constructs that have often been studied separately, but whose unique impact on well-being and mental illness is less clear, especially in the context of a natural hazard. The current study uses structural equation modeling to measure the unique contribution of hope, optimism, and hurricane-coping self-efficacy on mental well-being and mental illness in a community sample of 300 subjects who experienced Hurricane Harvey, recruited from Mechanical Turk.

Safe Patient Handling and Pressure Injury Prevention for Patients With Delayed Sternal Closure.

BACKGROUND: Pressure injuries are associated with increased morbidity, mortality, and cost. Patients with delayed sternal closure after cardiac surgery are at increased risk of developing pressure injury because of their reduced mobility and inability to undergo complete skin assessment. LOCAL PROBLEM: Safe patient handling of patients with delayed sternal closure is challenging because of mobility restrictions, leading to increased risk for patient and staff harm. METHODS: An interprofessional team composed of bedside nurses, ergonomic specialists, a wound ostomy continence nurse, and cardiothoracic surgeons developed a patient mobility protocol for patients with delayed sternal closure consisting of levitating the patient for thorough skin assessment and care. A multimodal educational strategy was used to disseminate the new protocol. Patient information was collected on the type of surgery, results of the levitation, completion of the skin assessment, and subsequent interventions. Staff injury related to this work was monitored. RESULTS: After implementation of the protocol, 84 levitations were performed including 50 patients. No staff injuries were reported. Comprehensive skin assessments and care were completed for 98% of patients. Five patients were identified with pressure injury development, and appropriate interventions were applied. DISCUSSION: A standardized patient mobility protocol for patients with delayed sternal closure that leveraged available equipment was successful in reducing the risk for injury among staff and patients. The protocol allowed assessment and care and thus also reduced the risk for pressure injury development in these patients. CONCLUSION: Development of an innovative protocol to safely mobilize patients with delayed sternal closure resulted in improved patient care and increased staff safety.

Establishment and characterization of patient-derived xenograft of a rare pediatric anaplastic pleomorphic xanthoastrocytoma (PXA) bearing a CDC42SE2-BRAF fusion.

Pleomorphic xanthoastrocytoma (PXA) is a rare subset of primary pediatric glioma with 70% 5-year disease free survival. However, up to 20% of cases present with local recurrence and malignant transformation into more aggressive type anaplastic PXA (AXPA) or glioblastoma. The understanding of disease etiology and mechanisms driving PXA and APXA are limited, and there is no standard of care. Therefore, development of relevant preclinical models to investigate molecular underpinnings of disease and to guide novel therapeutic approaches are of interest. Here, for the first time we established, and characterized a patient-derived xenograft (PDX) from a leptomeningeal spread of a patient with recurrent APXA bearing a novel CDC42SE2-BRAF fusion. An integrated -omics analysis was conducted to assess model fidelity of the genomic, transcriptomic, and proteomic/phosphoproteomic landscapes. A stable xenoline was derived directly from the patient recurrent tumor and maintained in 2D and 3D culture systems. Conserved histology features between the PDX and matched APXA specimen were maintained through serial passages. Whole exome sequencing (WES) demonstrated a high degree of conservation in the genomic landscape between PDX and matched human tumor, including small variants (Pearson's r = 0.794-0.839) and tumor mutational burden (~ 3 mutations/MB). Large chromosomal variations including chromosomal gains and losses were preserved in PDX. Notably, chromosomal gain in chromosomes 4-9, 17 and 18 and loss in the short arm of chromosome 9 associated with homozygous 9p21.3 deletion involving CDKN2A/B locus were identified in both patient tumor and PDX sample. Moreover, chromosomal rearrangement involving 7q34 fusion; CDC42SE-BRAF t (5;7) (q31.1, q34) (5:130,721,239, 7:140,482,820) was identified in the PDX tumor, xenoline and matched human tumor. Transcriptomic profile of the patient's tumor was retained in PDX (Pearson r = 0.88) and in xenoline (Pearson r = 0.63) as well as preservation of enriched signaling pathways (FDR Adjusted P < 0.05) including MAPK, EGFR and PI3K/AKT pathways. The multi-omics data of (WES, transcriptome, and reverse phase protein array (RPPA) was integrated to deduce potential actionable pathways for treatment (FDR < 0.05) including KEGG01521, KEGG05202, and KEGG05200. Both xenoline and PDX were resistant to the MEK inhibitors trametinib or mirdametinib at clinically relevant doses, recapitulating the patient's resistance to such treatment in the clinic. This set of APXA models will serve as a preclinical resource for developing novel therapeutic regimens for rare anaplastic PXAs and pediatric high-grade gliomas bearing BRAF fusions.

The Cost of Gunshot Wounds to the Head: An Unevenly Distributed Burden.

BACKGROUND: Despite the significant clinical consequences and socioeconomic costs of gunshot wounds to the head (GSWH), studies examining prehospital risk factors, geospatial patterns, and economic cost are lacking. METHODS: A retrospective analysis was performed for patients with GSWH (single or multiple injuries) presenting to the level one Ryder Trauma Center (hospital patients) as well as the Miami-Dade County Medical Examiner (ME) Department, from October 2013 to October 2015. In addition, ME data were queried from the previous decade (2008-2017) to analyze longitudinal trends. RESULTS: A total of 402 consecutive patients met the inclusion criteria: 297 (74%) presented to the ME and 105 (26%) presented to the hospital. GSWH in our cohort had a case fatality rate of 89%, predominantly affecting males, whites, and individuals who committed suicide, with a mean age of 41.9 ± 20.6 years. Hospital patients were more likely to be black males from low socioeconomic status (SES) regions involved in assault. Older white males were overrepresented in patients attempting and completing suicide and thus comprised a higher percentage of ME cases. Geospatial analysis of hospital patient injury zip codes shows that GSWH are significantly clustered in low-income urban centers with greater poverty rates. In Miami-Dade County, the economic burden of GSWH, as measured by total health care costs and lifetime productivity losses, was estimated to be $11,867,415 and $246,179,498, respectively. CONCLUSIONS: In the first analysis of GSWH with the inclusion of both hospital and ME data in a representative urban setting, our findings show prehospital risk factors and the unequal distribution of the significant economic costs of GSWH.

Neuro-oncology authorship trends in gender since 1944: a systematic review of 14,020 articles from five top-tier academic journals.

OBJECTIVE: This study was performed to compare authorship trends, by gender, in the neurosurgical oncology literature. METHODS: Complete author listings for neurosurgical oncology articles published between 1944 and 2021 in five top neuro-oncology journals were extracted from the PubMed database and journal websites on December 2, 2021. Author gender was characterized with the web application programming interface (API) genderize.io. The statistical significance (p < 0.05) of time-, journal-, and gender-based differences was determined by independent-samples t-test, chi-square test, and/or Fisher's exact test. RESULTS: A total of 14,020 articles were written by 67,115 unique authors occupying 97,418 authorship spots. The gender for 80,030 authorship positions (82.2%) was successfully characterized. Male authors were significantly more likely than the female authors to have a first-author publication, have a last-author publication, and have authored multiple articles within the data set. Among authors who published in multiple different years (n = 11,532), women had a shorter time window of publishing (5.46 vs 6.75 years between first and last publication: mean difference [MD] 1.28 [95% CI 1.06-1.50] years, p < 0.001). During this window, however, they were slightly more productive than the men, based on the mean number of publications per year (1.06 vs 1.01 articles: MD 0.05 [95% CI 0.02-0.09] articles, p = 0.002). The percentage of female authors on each neuro-oncology research team has increased by 3.3% (95% CI 2.6%-3.9%) per decade to a mean of 26.5% in the 2020s. Having a female last author was positively associated with having a female first author (OR 2.57 [95% CI 2.29-2.89]) and a higher proportion of women on the research team overall. The percentages of female first and last authors increased at significantly higher rates in medically oriented journals than in surgically oriented journals (first authors: 0.72% [95% CI 0.58%-0.87%] vs 0.36% [95% CI 0.30%-0.42%] per year, p < 0.001; and last authors: 0.50% [95% CI 0.38%-0.62%] vs -0.03% [95% CI -0.10% to 0.05%] per year, p < 0.001). CONCLUSIONS: Female authorship in top neuro-oncology journals has increased since the 1940s, with female-led teams showing greater gender diversity. However, female researchers lag behind their male counterparts in quantity of published research and are less likely to hold first or last authorship positions. This difference is more pronounced in the three neurosurgical oncology journals than in the two medical neuro-oncology journals, which may reflect the relatively low female representation in neurosurgery relative to medical oncology. Collectively, these trends have meaningful implications for career advancement, which is often dependent on academic productivity.

Image-Based Assessment of Natural Killer Cell Activity against Glioblastoma Stem Cells.

Glioblastoma (GBM) poses a significant challenge in oncology and stands as the most aggressive form of brain cancer. A primary contributor to its relentless nature is the stem-like cancer cells, called glioblastoma stem cells (GSCs). GSCs have the capacity for self-renewal and tumorigenesis, leading to frequent GBM recurrences and complicating treatment modalities. While natural killer (NK) cells exhibit potential in targeting and eliminating stem-like cancer cells, their efficacy within the GBM microenvironment is limited due to constrained infiltration and function. To address this limitation, novel investigations focusing on boosting NK cell activity against GSCs are imperative. This study presents two streamlined image-based assays assessing NK cell migration and cytotoxicity towards GSCs. It details protocols and explores the strengths and limitations of these methods. These assays could aid in identifying novel targets to enhance NK cell activity towards GSCs, facilitating the development of NK cell-based immunotherapy for improved GBM treatment.

Direct Bypass Surgery for Moyamoya and Steno-occlusive Vasculopathy: Clinical Outcomes, Intraoperative Blood Flow Analysis, Long-term Follow-up, and Long-term Bypass Patency in a Single Surgeon Case Series of 162 Procedures.

BACKGROUND: Cerebral extracranial-intracranial (EC-IC) direct bypass is a commonly used procedure for the treatment of cerebral hypoperfusion secondary to chronic steno-occlusive vasculopathy. We sought to determine clinical outcomes, intraoperative blood flow analysis, long term follow up, and long term patency rates from a single surgeon's series of direct cerebral bypass for moyamoya disease, moyamoya syndrome, and steno-occlusive disease. METHODS: We reviewed clinical, demographic, operative and neuroimaging records for all patients who underwent a direct EC-IC bypass by the senior author between August 1999 and November 2020. Primary outcomes analyzed were functional long-term outcomes (by modified Rankin score [mRS]), surgical complications, and short-term and long-term bypass patency. RESULTS: A total of 162 revascularization procedures in 124 patients were performed. Mean clinical follow up time was 2 years 11 months. The combined immediate and long term postoperative stroke and/or intracerebral hemorrhage rate was 6.2%. There were 17 bypasses (10%) that were found to be occluded at long-term follow-up, all but one were asymptomatic. Long-term graft occlusion was correlated with presence of complete collateralization on preoperative angiography but not cut flow index (CFI). Overall, patients had a significant clinical improvement with a mean mRS score 1.8 preoperatively and 1.2 postoperatively. CONCLUSIONS: In our consecutive series of patients treated with direct EC-IC cerebral bypass, there was significant improvement in functional outcome as measured by the mRS. The long term patency rate was 90%. There was a statistically significant correlation between complete or incomplete angiographic collateralization patterns and long-term bypass occlusion. There was no correlation between bypass type, clinical syndrome, or CFI and long-term occlusions. The role of bypass surgery and the need for surgical expertise remain strong in the treatment of moyamoya variants and a select group of atherosclerotic steno-occlusive patients.