Evaluation of Patient Education Materials From Large-Language Artificial Intelligence Models on Carpal Tunnel Release.

BACKGROUND: ChatGPT, an artificial intelligence technology, has the potential to be a useful patient aid, though the accuracy and appropriateness of its responses and recommendations on common hand surgical pathologies and procedures must be understood. Comparing the sources referenced and characteristics of responses from ChatGPT and an established search engine (Google) on carpal tunnel surgery will allow for an understanding of the utility of ChatGPT for patient education. METHODS: A Google search of "carpal tunnel release surgery" was performed and "frequently asked questions (FAQs)" were recorded with their answer and source. ChatGPT was then asked to provide answers to the Google FAQs. The FAQs were compared, and answer content was compared using word count, readability analyses, and content source. RESULTS: There was 40% concordance among questions asked by the programs. Google answered each question with one source per answer, whereas ChatGPT's answers were created from two sources per answer. ChatGPT's answers were significantly longer than Google's and multiple readability analysis algorithms found ChatGPT responses to be statistically significantly more difficult to read and at a higher grade level than Google's. ChatGPT always recommended "contacting your surgeon." CONCLUSION: A comparison of ChatGPT's responses to Google's FAQ responses revealed that ChatGPT's answers were more in-depth, from multiple sources, and from a higher proportion of academic Web sites. However, ChatGPT answers were found to be more difficult to understand. Further study is needed to understand if the differences in the responses between programs correlate to a difference in patient comprehension.

Patterns, procedures, and indications for pediatric surgery in a Tanzanian Refugee Camp: a 20-year experience.

Background: There are 103 million displaced people worldwide, 41% of whom are children. Data on the provision of surgery in humanitarian settings are limited. Even scarcer is literature on pediatric surgery performed in humanitarian settings, particularly protracted humanitarian settings. Methods: We reviewed patterns, procedures, and indications for pediatric surgery among children in Nyarugusu Refugee Camp using a 20-year retrospective dataset. Results: A total of 1221 pediatric surgical procedures were performed over the study period. Teenagers between the ages of 12 and 17 years were the most common age group undergoing surgery (n=991; 81%). A quarter of the procedures were performed on local Tanzanian children seeking care in the camp (n=301; 25%). The most common procedures performed were cesarean sections (n=858; 70%), herniorrhaphies (n=197; 16%), and exploratory laparotomies (n=55; 5%). Refugees were more likely to undergo exploratory laparotomy (n=47; 5%) than Tanzanian children (n=7; 2%; p=0.032). The most common indications for exploratory laparotomy were acute abdomen (n=24; 44%), intestinal obstruction (n=10; 18%), and peritonitis (n=9; 16%). Conclusions: There is a significant volume of basic pediatric general surgery performed in the Nyarugusu Camp. Services are used by both refugees and local Tanzanians. We hope this research will inspire further advocacy and research on pediatric surgical services in humanitarian settings worldwide and illuminate the need for including pediatric refugee surgery within the growing global surgery movement.

What Proportion of East African Refugees Report Musculoskeletal Problems? A Cross-sectional Survey.

BACKGROUND: Musculoskeletal conditions are the leading cause of disability worldwide and disproportionally affect individuals in low-income and middle-income countries. There is a dearth of evidence on musculoskeletal problems among refugees, 74% of whom reside in low-income and middle-income countries. QUESTIONS/PURPOSES: (1) What proportion of refugees in Nyarugusu Camp, Kigoma, western Tanzania, are affected by musculoskeletal problems and what are the characteristics of those individuals? (2) What are the characteristics of these musculoskeletal problems, including their causes, location, and duration? (3) What forms of healthcare do those with musculoskeletal problems seek, including those for both musculoskeletal and nonmusculoskeletal problems? METHODS: We conducted a cross-sectional study among refugees in Nyarugusu Camp, using the Surgeons OverSeas Assessment of Surgical Need tool. The Surgeons OverSeas Assessment of Surgical Need tool is a validated population-based survey tool developed for use in limited-resource settings that is intended to determine the prevalence of surgical disease in a community. It uses a cluster random sampling methodology with house-to-house data collection in the form of a verbal head-to-toe examination that is performed by a trained community healthcare worker. A total of 99% responded, and 3574 records were analyzed. The mean age of respondents was 23 ± 18 years, with under 18 as the most-represented age group (44% [1563]). A total of 57% (2026) of respondents were women, 79% (2802 of 3536) were generally healthy, and 92% (3297 of 3570) had visited a camp medical facility. Only records endorsing musculoskeletal problems (extremity or back) were included in this analysis. Using all refugees surveyed as our denominator and refugees who endorsed a musculoskeletal problem (extremity or back) as the numerator, we calculated the proportion of refugees who endorsed a musculoskeletal problem. We then analyzed the characteristics of those endorsing musculoskeletal problems, including their healthcare-seeking behavior, and the characteristics of the musculoskeletal problems themselves. RESULTS: Among 3574 refugees interviewed, 22% (769) reported musculoskeletal problems, with 17% (609) reporting extremity problems and 7% (266) reporting back problems. Among all people surveyed, 8% (290) reported current extremity problems while 5% (188) reported current back problems. Among those reporting musculoskeletal problems, respondents younger than 18 years were the most-represented age group (28% [169 of 609]) whereas respondents between 30 and 44 years of age were the most-represented age group for back problems (29% [76 of 266]). Wounds from an injury or trauma (24% [133 of 557]) and acquired disability (24% [133 of 557]) were the most-common causes of extremity problems, whereas acquired disability (53% [97 of 184]) followed by a wound not from injury or trauma (25% [45 of 184]) were the most common causes of back problems. Fifty percent (303) of those with extremity problems characterized it as disabling, whereas 76% (203) of those with back problems did. CONCLUSION: Over one of five refugees endorsed musculoskeletal problems, which are most often caused by acquired disease and injury. These musculoskeletal problems are often characterized as disabling, yet only slightly more than half have sought treatment for problems. This warrants further research on care-seeking behavior in this setting, and emphasizes that investing in the spectrum of musculoskeletal health systems, including medical management and rehabilitation services, is critical to decreasing disability caused by musculoskeletal problems. LEVEL OF EVIDENCE: Level IV, prognostic study.

A Scoping Review of the Essential Components of Emergency Medical Response Systems for Mass Casualty Incidents.

OBJECTIVE: Emergency medical (EM) response systems require extensive coordination, particularly during mass casualty incidents (MCIs). The recognition of preparedness gaps and contextual priorities to MCI response capacity in low- and middle-income countries (LMICs) can be better understood through the components of EM reponse systems. This study aims to delineate essential components and provide a framework for effective emergency medical response to MCIs. METHODS: A scoping review was conducted using 4 databases. Title and abstract screening was followed by full-text review. Thematic analysis was conducted to identify themes pertaining to the essential components and integration of EM response systems. RESULTS: Of 20,456 screened citations, 181 articles were included in the analysis. Seven major and 40 sub-themes emerged from the content analysis as the essential components and supportive elements of MCI medical response. The essential components of MCI response were integrated into a framework demonstrating interrelated connections between essential and supportive elements. CONCLUSIONS: Definitions of essential components of EM response to MCIs vary considerably. Most literature pertaining to MCI response originates from high income countries with far fewer reports from LMICs. Integration of essential components is needed in different geopolitical and economic contexts to ensure an effective MCI emergency medical response.

Implementing HIV Prevention in Sub-Saharan Africa: A Systematic Review of Interventions Targeting Systems, Communities, and Individuals.

HIV remains a threat to global public health, disproportionately affecting countries across Sub-Saharan Africa. Although treatment and access to care have improved, prevention remains critical to ending new HIV infections by 2030. A variety of prevention strategies exist, yet their effectiveness is difficult to measure and variable due to the nature of the interventions and vulnerability of the intervention during implementation. This systematic review of 51 studies synthesizes data on the implementation and evaluation of evidence-based HIV prevention interventions across Sub-Saharan Africa. Studies were included if they occurred between January 1, 2008, and December 31, 2019, inclusive in Sub-Saharan Africa, were written in English, implemented an HIV prevention intervention in the field, and had reportable results. Using a modified social-ecological model for HIV prevention, we divided studies into three categories: interventions targeting health systems (n = 16), communities (n = 8), and individuals (n = 27). Across all categories, the data emphasized preventing mother-to-child transmission (PMTCT), medical interventions, and psychosocial interventions. The most successful programs bundled several interventions that were integrated into the health system. There is a notable lack of interventions targeting key populations and there are significant rates of loss to follow up (LTFU) across many studies. This review provides insight into the prioritization of evidence-based HIV prevention interventions across Sub-Saharan Africa.

Patterns of referral for refugees in western Tanzania: a retrospective review.

Introduction: access to essential secondary and tertiary healthcare, including surgery and medical sub-specialties, is a challenge in low-and-middle income countries (LMICs), especially for displaced populations. Referrals from refugee camps are highly regulated and may pose barriers to accessing essential secondary healthcare in a timely manner. Refugee referral systems and the ways they interact with national systems are poorly understood. Such information is necessary for resource allocation and prioritization, optimizing patient outcomes, national-level planning, and investment in capacity-building. Methods: a retrospective review of referrals from Nyarugusu Refugee Camp in Tanzania to Kabanga Hospital between January 2016-May 2017 was conducted. Data was collected from logbooks on patient demographics, diagnosis, and reason for referral. Diagnoses and reasons for referral were further coded by organ system and specific referral codes, respectively. Results: there were 751 entries in the referral logbook between January 2016 and May 2017. Of these, 79 (10.5%) were excluded as they were caretakers or missing both diagnoses and reason for referral resulting in 672 (89.5%) total entries for analysis.The most common organ system of diagnosis was musculoskeletal (171, 25.5%) followed by head, ear, eye, nose and throat (n=164, 24.4%) and infectious disease (n=92, 13.7%). The most common reason for referral was imaging (n=250, 37.2%) followed by need for a specialist (n=214, 31.9%) and further management (n=116, 17.3%). X-ray comprised the majority of imaging referred (n=249, 99.6%). The most common specialties referred to were ophthalmology (n=104, 48.6%) followed by surgery (n=63, 29.4%), and otolaryngology (ENT) (n=17, 7.9%). Conclusion: given a large burden of referral for refugee patients and sharing of in and out-of-camp healthcare facilities with nationals, refugees should be included in national health care plans and have clear referral processes. Epidemiological data that include these intertwined referral patterns are necessary to promote efficient resource allocation, reduce unnecessary referrals, and prevent delays in care that could affect patient outcomes. International agencies, NGOs, and governments should conduct cost analyses to explore innovative capacity-building projects for secondary care in camp-based facilities.

External Validation of a Neural Network Model in Aneurysmal Subarachnoid Hemorrhage: A Comparison With Conventional Logistic Regression Models.

BACKGROUND: Interest in machine learning (ML)-based predictive modeling has led to the development of models predicting outcomes after aneurysmal subarachnoid hemorrhage (aSAH), including the Nijmegen acute subarachnoid hemorrhage calculator (Nutshell). Generalizability of such models to external data remains unclear. OBJECTIVE: To externally validate the performance of the Nutshell tool while comparing it with the conventional Subarachnoid Hemorrhage International Trialists (SAHIT) models and to review the ML literature on outcome prediction after aSAH and aneurysm treatment. METHODS: A prospectively maintained database of patients with aSAH presenting consecutively to our institution in the 2013 to 2018 period was used. The web-based Nutshell and SAHIT calculators were used to derive the risks of poor long-term (12-18 months) outcomes and 30-day mortality. Discrimination was evaluated using the area under the curve (AUC), and calibration was investigated using calibration plots. The literature on relevant ML models was surveyed for a synopsis. RESULTS: In 269 patients with aSAH, the SAHIT models outperformed the Nutshell tool (AUC: 0.786 vs 0.689, P = .025) in predicting long-term functional outcomes. A logistic regression model of the Nutshell variables derived from our data achieved adequate discrimination (AUC = 0.759) of poor outcomes. The SAHIT models outperformed the Nutshell tool in predicting 30-day mortality (AUC: 0.810 vs 0.636, P < .001). Calibration properties were more favorable for the SAHIT models. Most published aneurysm-related ML-based outcome models lack external validation and usable testing platforms. CONCLUSION: The Nutshell tool demonstrated limited performance on external validation in comparison with the SAHIT models. External validation and the dissemination of testing platforms for ML models must be emphasized.

Adapting the 5-factor modified frailty index for prediction of postprocedural outcome in patients with unruptured aneurysms.

OBJECTIVE: The 5-factor modified frailty index (mFI-5) is a practical tool that can be used to estimate frailty by measuring five accessible factors: functional status, history of diabetes, chronic obstructive pulmonary disease, congestive heart failure, and hypertension. The authors aimed to validate the utility of mFI-5 for predicting endovascular and microsurgical treatment outcomes in patients with unruptured aneurysms. METHODS: A prospectively maintained database of consecutive patients with unruptured aneurysm who were treated with clip placement or endovascular therapy was used. Because patient age is an important predictor of treatment outcomes in patients with unruptured aneurysm, mFI-5 was supplemented with age to create the age-supplemented mFI-5 (AmFI-5). Associations of scores on these indices with major complications (symptomatic ischemic or hemorrhagic stroke, pulmonary embolism, pneumonia, or surgical site infection requiring reoperation) were evaluated. Validation was carried out with the American College of Surgeons National Surgical Quality Improvement Program (NSQIP) database (2006-2017). RESULTS: The institutional database included 275 patients (88 underwent clip placement, and 187 underwent endovascular treatment). Multivariable analysis of the surgical cohort showed that major complication was significantly associated with mFI-5 (OR 2.0, p = 0.046) and AmFI-5 (OR 1.9, p = 0.028) scores. Significant predictive accuracy for major complications was provided by mFI-5 (c-statistic = 0.709, p = 0.011) and AmFI-5 (c-statistic = 0.720, p = 0.008). The American Society of Anesthesiologists Physical Status Classification System (ASA) provided poor discrimination (area under the curve = 0.541, p = 0.618) that was significantly less than that of mFI-5 (p = 0.023) and AmFI-5 (p = 0.014). Optimal relative fit was achieved with AmFI-5, which had the lowest Akaike information criterion value. Similar results were obtained after equivalent analysis of the endovascular cohort, with additional significant associations between index scores and length of stay (ß = 0.6 and p = 0.009 for mFI-5; ß = 0.5 and p = 0.003 for AmFI-5). In 1047 patients who underwent clip placement and were included in the NSQIP database, mFI-5 (p = 0.001) and AmFI-5 (p < 0.001) scores were significantly associated with severe postoperative adverse events and provided greater discrimination (c-statistic = 0.600 and p < 0.001 for mFI-5; c-statistic = 0.610 and p < 0.001 for AmFI-5) than ASA score (c-statistic = 0.580 and p = 0.003). CONCLUSIONS: mFI-5 and AmFI-5 represent potential predictors of procedure-related complications in unruptured aneurysm patients. After further validation, integration of these tools into clinical workflows may optimize patients for intervention.

Development of an Open-Access Webinar Series on Pathways for Global Surgery Engagement for Applicants to US Residency Programs.

BACKGROUND: Global surgery (GS) training pathways in residency are unclear and vary by specialty and program. Furthermore, information on these pathways is not always accessible. To address this gap, we produced a collection of open-access webinars for senior medical students focused on identifying GS training pathways during residency. METHODS: The Global Surgery Student Alliance (GSSA) is a national nonprofit that engages US students and trainees in GS education, research, and advocacy. GSSA organized nine one-hour, specialty-specific webinars featuring residents of surgical specialties, anesthesia, and OBGYN programs. Live webinars were produced via Zoom from August to October 2020, and all recordings were posted to the GSSA YouTube channel. Medical students moderated webinars with predetermined standardized questions and live questions submitted by attendees. Participant data were collected in mandatory registration forms. RESULTS: A total of 539 people were registered for 9 webinars. Among registrants, 189 institutions and 36 countries were represented. Registrants reported education/training levels from less than undergraduate education to attending physicians, while medical students represented the majority of registrants. Following the live webinars, YouTube recordings of the events were viewed 839 times. Webinars featuring otolaryngology and general surgery residents accrued the greatest number of registrations, while anesthesia accrued the least. CONCLUSIONS: Medical students at all levels demonstrated interest in both the live and recorded specialty-specific webinars on GS in residency. To address the gap in developing global surgery practitioners, additional online, open-access education materials and mentorship opportunities are needed for students applying to US residencies.

Microsurgical resection versus stereotactic radiosurgery for low-grade intracranial arteriovenous malformations: A 27-year institutional experience.

The role of microsurgery and radiosurgery in the management of low-grade (Spetzler-Martin grade 1 and 2) arteriovenous malformations (AVMs) remains controversial. We aimed to compare outcomes of low-grade AVMs following microsurgery and radiosurgery using a database of AVM patients presenting between 1990 and 2017. Procedure-related complications, obliteration, and functional status at last follow-up were compared between groups. Hemorrhage-free survival was compared using Kaplan-Meier analysis with subgroup analyses by rupture status on presentation. The study involved 233 patients, of which 113 and 120 were treated with microsurgery and radiosurgery, respectively. The complication rates were statistically comparable between both treatment modalities. Mean follow-up time was 5.1 ± 5.2 years. In the complete cohort, there was no significant difference in hemorrhage-free survival between microsurgery and radiosurgery (log-rank p = 0.676, Breslow p = 0.493). When excluding procedure-related hemorrhage and partial resection, hemorrhage-free survival was significantly higher in the surgically treated cohort (log-rank = 0.094, Breslow p = 0.034). The obliteration rate was significantly higher in the surgical cohort (96% vs. 57%, p < 0.001), while functional status was similar. Microsurgery may offer superior hemorrhage-free survival in the early post-treatment period and demonstrates equivalent long-term hemorrhage control and functional outcome at 5 years compared to radiosurgery with nearly complete obliteration rates. Persistent neurologic deficits following microsurgery and symptomatic cerebral edema represent important treatment risks despite low SM grading. Appropriate patient selection even when dealing with low-grade AVMs is advised, as judicious patient selection and emphasis on technical success can minimize procedure-related hemorrhage and the incidence of subtotal resection.

Humanitarian surgical service utilization by a host country population: comparing surgery patterns between refugees and Tanzanians using an interrupted time-series analysis.

BACKGROUND: While current estimates suggest that up to three million additional surgical procedures are needed to meet the needs of forcibly displaced populations, literature on surgical care for refugee or forced migrant populations has often focused on acute phase and war-related trauma or violence with insufficient attention to non-war related pathologies. To our knowledge, no study has compared refugee versus host population utilization of surgical services in a refugee camp-based hospital over such an extended period of twenty years. The aim of this paper is to first describe the patterns of surgical care by comparing refugee and host population utilization of surgical services in Nyarugusu refugee camp between 2000 and 2020, then evaluate the impact of a large influx of refugees in 2015 on refugee and host population utilization. METHODS: The study was based on a retrospective review of surgical logbooks in Nyarugusu refugee camp (Kigoma, Tanzania) between 2000 and 2020. We utilized descriptive statistics and multiple group, interrupted time series methodology to assess baseline utilization of surgical services by a host population (Tanzanians) compared to refugees and trends in utilization before and after a large influx of Burundian refugees in 2015. RESULTS: A total of 10,489 operations were performed in Nyarugusu refugee camp between 2000 and 2020. Refugees underwent the majority of procedures in this dataset (n = 7,767, 74.0%) versus Tanzanians (n = 2,722, 26.0%). The number of surgeries increased over time for both groups. The top five procedures for both groups included caesarean section, bilateral tubal ligation, herniorrhaphy, exploratory laparotomy and hysterectomy. In our time series model, refugees had 3.21 times the number of surgeries per quarter at baseline when compared to Tanzanians. The large influx of Burundian refugees in 2015 impacted surgical output significantly with a 38% decrease (IRR = 0.62, 95% CI 0.46-0.84) in surgeries in the Tanzanian group and a non-significant 20% increase in the refugee group (IRR = 1.20, 95% CI 0.99-1.46). The IRR for the difference-in-difference (ratio of ratios of post versus pre-intervention slopes between refugees and Tanzanians) was 1.04 (95% CI 1.00-1.07), and this result was significant (p=0.028). CONCLUSIONS: Surgical care in conflict and post-conflict settings is not limited to war or violence related trauma but instead includes a large burden of obstetrical and general surgical pathology. Host population utilization of surgical services in Nyarugusu camp accounted for over 25% of all surgeries performed, suggesting some host population benefit of the protracted refugee situation in western Tanzania. Host population utilization of surgical services was apparently different after a large influx of refugees from Burundi in 2015.

Emphasizing the Role of Neurosurgery Within Global Health and National Health Systems: A Call to Action.

Background: Worldwide, neurological disorders are the leading cause of disability-adjusted life years lost and the second leading cause of death. Despite global health capacity-building efforts, each year, 22.6 million individuals worldwide require neurosurgeon's care due to diseases such as traumatic brain injury and hydrocephalus, and 13.8 million of these individuals require surgery. It is clear that neurosurgical care is indispensable in both national and international public health discussions. This study highlights the role neurosurgeons can play in supporting the global health agenda, national surgical plans, and health strengthening systems (HSS) interventions. Methods: Guided by a literature review, the authors discuss key topics such as the global burden of neurosurgical diseases, the current state of neurosurgical care around the world and the inherent benefits of strong neurosurgical capability for health systems. Results: Neurosurgical diseases make up an important part of the global burden of diseases. Many neurosurgeons possess the sustained passion, resilience, and leadership needed to advocate for improved neurosurgical care worldwide. Neurosurgical care has been linked to 14 of the 17 Sustainable Development Goals (SDGs), thus highlighting the tremendous impact neurosurgeons can have upon HSS initiatives. Conclusion: We recommend policymakers and global health actors to: (i) increase the involvement of neurosurgeons within the global health dialogue; (ii) involve neurosurgeons in the national surgical system strengthening process; (iii) integrate neurosurgical care within the global surgery movement; and (iv) promote the training and education of neurosurgeons, especially those residing in Low-and middle-income countries, in the field of global public health.

Epidemiology of surgery in a protracted humanitarian setting: a 20-year retrospective study of Nyarugusu Refugee Camp, Kigoma, Western Tanzania.

BACKGROUND: There are 80 million forcibly displaced persons worldwide, 26.3 million of whom are refugees. Many refugees live in camps and have complex health needs, including a high burden of non-communicable disease. It is estimated that 3 million procedures are needed for refugees worldwide, yet very few studies exist on surgery in refugee camps, particularly protracted refugee settings. This study utilizes a 20-year dataset, the longest dataset of surgery in a refugee setting to be published to date, to assess surgical output in a setting of protracted displacement. METHODS: A retrospective review of surgeries performed in Nyarugusu Camp was conducted using paper logbooks containing entries between November 2000 and September 2020 inclusive. Abstracted data were digitized into standard electronic form and included date, patient nationality, sex, age, indication, procedure performed, and anesthesia used. A second reviewer checked 10% of entries for accuracy. Entries illegible to both reviewers were excluded. Demographics, indication for surgery, procedures performed, and type of anesthesia were standardized for descriptive analysis, which was performed in STATA. RESULTS: There were 10,799 operations performed over the 20-year period. Tanzanians underwent a quarter of the operations while refugees underwent the remaining 75%. Ninety percent of patients were female and 88% were 18 years of age or older. Caesarean sections were the most common performed procedure followed by herniorrhaphies, tubal ligations, exploratory laparotomies, hysterectomies, appendectomies, and repairs. The most common indications for laparotomy procedures were ectopic pregnancy, uterine rupture, and acute abdomen. Spinal anesthesia was the most common anesthesia type used. Although there was a consistent increase in procedural volume over the study period, this is largely explained by an increase in overall camp population and an increase in caesarean sections rather than increases in other, specific surgical procedures. CONCLUSION: There is significant surgical volume in Nyarugusu Camp, performed by staff physicians and visiting surgeons. Both refugees and the host population utilize these surgical services. This work provides context to the surgical training these settings require, but further study is needed to assess the burden of surgical disease and the extent to which it is met in this setting and others.

Comparison of management approaches in deep-seated intracranial arteriovenous malformations: Does treatment improve outcome?

Deep-seated intracranial arteriovenous malformations (AVMs) represent a subset of AVMs characterized by variably reported outcomes regarding the risk of hemorrhage, microsurgical complications, and response to stereotactic radiosurgery (SRS). We aimed to compare outcomes of microsurgery, SRS, endovascular therapy, and conservative follow-up in deep-seated AVMs. A prospectively maintained database of AVM patients (1990-2017) was queried to identify patients with ruptured and unruptured deep-seated AVMs (extension into thalamus, basal ganglia, or brainstem). Comparisons of hemorrhage-free survival and poor functional outcome (modified Rankin scale [mRS] > 2) were performed between conservative management, microsurgery (±pre-procedural embolization), SRS (±pre-procedural embolization), and embolization utilizing multivariable Cox and logistic regression analyses controlling for univariable factors with p < 0.05. Of 789 AVM patients, 102 had deep-seated AVMs (conservative: 34; microsurgery: 6; SRS: 54; embolization: 8). Mean follow-up time was 6.1 years and did not differ significantly between management groups (p = 0.393). Complete obliteration was achieved in 49% of SRS patients. Upon multivariable analysis controlling for baseline rupture with conservative management as a reference group, embolization was associated with an increased hazard of hemorrhage (HR = 6.2, 95%CI [1.1-40.0], p = 0.037), while microsurgery (p = 0.118) and SRS (p = 0.167) provided no significant protection from hemorrhage. Controlling for baseline mRS, microsurgery was associated with an increased risk of poor outcome (OR = 9.2[1.2-68.3], p = 0.030), while SRS (p = 0.557) and embolization (p = 0.541) did not differ significantly from conservative management. Deep AVMs harbor a high risk of hemorrhage, but the benefit from intervention Remains uncertain. SRS may be a relatively more effective approach if interventional therapy is indicated.

Monocyte-based inflammatory indices predict outcomes following aneurysmal subarachnoid hemorrhage.

The contribution of specific immune cell populations to the post-hemorrhagic inflammatory response in aneurysmal subarachnoid hemorrhage (aSAH) and correlations with clinical outcomes, such as vasospasm and functional status, remains unclear. We aimed to compare the predictive value of leukocyte ratios that include monocytes as compared to the neutrophil-to-lymphocyte ratio (NLR) in aSAH. A prospectively accrued database of consecutive patients presenting to our institution with aSAH between January 2013 and December 2018 was used. Patients with signs and symptoms of infection (day 1-3) were excluded. Admission values of the NLR, monocyte-neutrophil-to-lymphocyte ratio (M-NLR), and lymphocyte-to-monocyte ratio (LMR) were calculated. Associations with functional status, the primary outcome, and vasospasm were evaluated using univariable and multivariable logistic regression analyses. In the cohort of 234 patients with aSAH, the M-NLR and LMR, but not the NLR, were significantly associated with poor functional status (modified Rankin scale > 2) at 12-18 months following discharge (p = 0.001, p = 0.023, p = 0.161, respectively). The area under the curve for predicting poor functional status was significantly lower for the NLR (0.543) compared with the M-NLR (0.603, p = 0.024) and LMR (0.608, p = 0.040). The M-NLR (OR = 1.01 [1.01-1.02]) and LMR (OR = 0.88 [0.78-0.99]) were independently associated with poor functional status while controlling for age, hypertension, Fisher grade, and baseline clinical status. The LMR was significantly associated with vasospasm (OR = 0.84 [0.70-0.99]) while adjusting for age, hypertension, Fisher grade, aneurysm size, and current smoking. Inflammatory indices that incorporate monocytes (e.g., M-NLR and LMR), but not those that include only neutrophils, predict outcomes after aSAH.

Hemorrhage Following Complete Arteriovenous Malformation Resection With No Detectable Recurrence: Insights From a 27-Year Registry.

BACKGROUND: Although recurrence and de novo formation of arteriovenous malformations (AVMs) have been reported following complete resection, the occurrence of hemorrhage in the same location of an AVM with no detectable lesion (lesion-negative hemorrhage) has not been described after microsurgery. OBJECTIVE: To characterize the incidence and properties of lesion-negative hemorrhage following complete microsurgical resection. METHODS: A prospectively maintained registry of AVM patients seen at our institution between 1990 and 2017 was used. Microsurgically treated patients were selected, and the incidence of a lesion-negative hemorrhage was calculated and described with a Kaplan-Meier curve. Baseline characteristics as well as functional outcome at last follow-up were compared between patients with and without a lesion-negative hemorrhage. RESULTS: From a total of 789 AVM patients, 619 (79%) were treated, and 210 out of 619 patients (34%) underwent microsurgery with or without preoperative embolization or radiosurgery. The microsurgically treated cohort was followed up for a mean of 6.1 ± 3.0 yr after surgery with 5 (2.4%) patients experiencing postresection lesion-negative hemorrhage (3.9 per 1000 person-years) at an average of 8.6 ± 9.0 yr following surgery. Follow-up angiograms after hemorrhage (up to 2 mo posthemorrhage) confirmed the absence of a recurrent or de novo AVM in all cases. All patients with a lesion-negative hemorrhage initially presented with rupture before resection (Fisher P = .066; log-rank P = .057). The occurrence of a lesion-negative hemorrhage was significantly associated with worse modified Rankin scale scores at last follow-up (P = .031). CONCLUSION: A lesion-negative hemorrhage can occur following complete microsurgical resection in up to 2.4% of patients. Exploration of possible underlying causes is warranted.

Aging Patient Population With Ruptured Aneurysms: Trend Over 28 Years.

BACKGROUND: Given increasing life expectancy in the United States and worldwide, the proportion of elderly patients affected by aneurysmal subarachnoid hemorrhage (aSAH) would be expected to increase. OBJECTIVE: To determine whether an aging trend exists in the population of aSAH patients presenting to our institution over a 28-yr period. METHODS: A prospectively maintained database of consecutive patients presenting to our institution with subarachnoid hemorrhage between January 1991 and December 2018 was utilized. The 28-yr period was categorized into 4 successive 7-yr quarter intervals. The age of patients was compared among these intervals, and yearly trends were derived using linear regression. RESULTS: The cohort consisted of 1671 ruptured aneurysm patients with a mean age of 52.8 yr (standard deviation = 15.0 yr). Over the progressive 7-yr time intervals during the 28-yr period, there was an approximately 4-fold increase in the proportion of patients aged 80 yr or above (P < .001) and an increase in mean patient age from 51.2 to 54.6 yr (P = .002). Independent of this trend but along the same lines, there was a 29% decrease in the proportion of younger patients (<50 yr) from 49% to 35%. On linear regression, there was 1-yr increase in mean patient age per 5 calendar years (P < .001). CONCLUSION: Analyses of aSAH patients demonstrate an increase in patient age over time with a considerable rise in the proportion of octogenarian patients and a decrease in patients younger than 50 yr. This aging phenomenon presents a challenge to the continued improvement in outcomes of aSAH patients.

Corpus callosum axon diameter relates to cognitive impairment in multiple sclerosis.

OBJECTIVE: To evaluate alterations in apparent axon diameter and axon density obtained by high-gradient diffusion MRI in the corpus callosum of MS patients and the relationship of these advanced diffusion MRI metrics to neurologic disability and cognitive impairment in MS. METHODS: Thirty people with MS (23 relapsing-remitting MS [RRMS], 7 progressive MS [PMS]) and 23 healthy controls were scanned on a human 3-tesla (3T) MRI scanner equipped with 300 mT/m maximum gradient strength using a comprehensive multishell diffusion MRI protocol. Data were fitted to a three-compartment geometric model of white matter to estimate apparent axon diameter and axon density in the midline corpus callosum. Neurologic disability and cognitive function were measured using the Expanded Disability Status Scale (EDSS), Multiple Sclerosis Functional Composite (MSFC), and Minimal Assessment of Cognitive Function in MS battery. RESULTS: Apparent axon diameter was significantly larger and axon density reduced in the normal-appearing corpus callosum (NACC) of MS patients compared to healthy controls, with similar trends seen in PMS compared to RRMS. Larger apparent axon diameter in the NACC of MS patients correlated with greater disability as measured by the EDSS (r = 0.555, P = 0.007) and poorer performance on the Symbol Digits Modalities Test (r = -0.593, P = 0.008) and Brief Visuospatial Memory Test-Revised (r = -0.632, P < 0.01), tests of interhemispheric processing speed and new learning and memory, respectively. INTERPRETATION: Apparent axon diameter in the corpus callosum obtained from high-gradient diffusion MRI is a potential imaging biomarker that may be used to understand the development and progression of cognitive impairment in MS.