Canadian Women in Neurosurgery: From Early Pioneers to World Leaders.

BACKGROUND: Since the emergence of neurosurgery as a distinct specialty ∼100 years ago in Canada, it took >40 years for Canadian women to enter the field in the province of Quebec, and longer in the other provinces. METHODS: We provide a historical overview of Canadian women in neurosurgery, from the early pioneers to the modern-day leaders and innovators in the field. We also define the current participation of women in Canadian neurosurgery. Chain-referral sampling, historical books, interviews, personal communications, and online resources were used as data sources. RESULTS: Our historical review highlights the exceptional journey and unique experiences of female neurosurgeons, describes their achievements, and identifies career obstacles and enabling factors. We also incorporate comments from Canadian female neurosurgeons, both retired and in active practice, addressing gender inequities in the field, and provide advice and encouragement to the new generations to come. Despite the achievements of these female trailblazers, women represent a small proportion of the Canadian neurosurgery trainees and the active workforce, in stark contrast to the increasing number of women in medical school. CONCLUSIONS: To the best of our knowledge, this study represents the first historical overview of female women neurosurgeons in Canada. Providing a historical context will help us to better understand the important role of women in modern neurosurgery, identify persistent gender issues in the field, and provide a vision for aspiring female neurosurgeons.

Acute Traumatic Subdural Hematoma and Anticoagulation Risk.

BACKGROUND: Anticoagulation is used to prevent thromboembolic events. It is a common practice to hold anticoagulation in the first few days following a traumatic brain injury (TBI) with intracranial hemorrhage. However, traumatic subdural hematomas (SDH) are prone to re-hemorrhage long after the trauma. Data are scarce in the literature on the best timing to resume anticoagulation following a TBI. METHODS: Review of 95 consecutive patients admitted to a level 1 trauma center with a diagnosis of traumatic SDH and requiring anticoagulation. The reasons for anticoagulation, the amount of time without anticoagulation, CT characteristics, and the incidence of thromboembolic events or SDH re-hemorrhage were collected. RESULTS: 41.3% used anticoagulation for coronary artery disease and peripheral vascular disease, 24% for atrial fibrillation, 12% for cardiac valve replacement, and 12% for venous thromboembolic events. Anticoagulation was held a median of 67 days. For most patients (82.1%), anticoagulation was re-introduced once the SDH had completely resolved. For 17.9%, anticoagulation was restarted while the SDH had not completely resolved. One (1.1%) patient suffered from an atrial clot while anticoagulation was held. For those with residual SDH, 41.2% suffered from a SDH re-hemorrhage and 17.6% required surgery. The risk of re-hemorrhage climbed to 62.5% if the SDH remnant was large. CONCLUSION: Anticoagulation while there is a residual SDH was associated with a significant risk of re-hemorrhage. This risk should be weighed against the risk of holding anticoagulation.

Penn State equation versus indirect calorimetry for nutritional assessment in patients with traumatic brain injury.

BACKGROUND: Nutritional assessment can be challenging in patients with traumatic brain injury (TBI), and indirect calorimetry may be a more suitable method than predictive equations. We compared the Penn State equation versus the gold standard of indirect calorimetry for the nutritional assessment of patients with TBI, and quantified the difference between nutritional requirements and actual patient intake. METHODS: This single-centre, prospective cohort study included patients with moderate (Glasgow Coma Scale score 9-12) and severe (Glasgow Coma Scale score 3-8) TBI admitted to the Montreal General Hospital intensive care unit (ICU) between June 2018 and March 2019. Penn State equation estimates and indirect calorimetry measurements were collected, and actual intake was drawn from medical records. We compared the 2 assessment methods using a Spearman correlation coefficient. RESULTS: Twenty-three patients with TBI (moderate in 7 and severe in 16) were included in the study. Overall, there was a moderate positive correlation between the Penn State equation estimate and indirect calorimetry readings (correlation coefficient 0.457, p = 0.03); however, the correlation was weaker in severe TBI (correlation coefficient 0.174, p = 0.5) than in moderate TBI (correlation coefficient 0.929, p = 0.003). When compared to indirect calorimetry assessment, patients received 5.4% (p = 0.5) of required intake on the first day and 43.9% (p = 0.8) of required daily intake throughout their ICU stay. CONCLUSION: Patients with moderate or severe TBI in the ICU received less than 50% of their nutritional requirements. The difference between the Penn State equation and indirect calorimetry assessments was most noticeable for patients with severe TBI, which indicates that indirect calorimetry may be a more suitable tool for assessment of nutritional needs in this population.

Determinants of hyponatremia following a traumatic brain injury.

BACKGROUND: Hyponatremia is common in patients with central nervous system disease. It may prolong hospitalization and increase morbidity and mortality. However, the incidence and risks factors remain largely unknown in traumatic brain injury (TBI). The objectives of this study are to characterize hyponatremia in TBI patients and find its main risk factors. METHODS: All patients admitted with a diagnosis of acute TBI over a 1-year period were included, except patients with known chronic hyponatremia, those who died within 72 h, and those receiving hyperosmolar therapy to treat their intracranial hypertension. Sodium levels throughout hospitalization were collected. Post-traumatic hyponatremia was defined as follows: borderline (1-2 points below normal and 1-2 days duration) and significant (more than 2 points below normal and/or more than 2 days duration). Demographic data, GCS, mechanism of injury, and CT findings were collected. These factors were correlated to the incidence of hyponatremia. RESULTS: Hyponatremia was found in 29% of the 283 included patients and was significant in 2/3 of the cases. Significant hyponatremia had a narrower peak, between 7 and 11 days, while borderline hyponatremia started earlier and was more distributed in time. Factors associated with hyponatremia were greater age (p = 0.004), worse ISS (p = 0.017), worse Marshall Grade on CT (p = 0.007), and a diffuse pattern of injury on CT (p < 0.001). Significant hyponatremia was associated with: a diffuse pattern of injury on CT (p = 0.032), the presence of intracerebral hemorrhage (p = 0.027), and multiple lesions on CT (p = 0.043). CONCLUSIONS: Post-traumatic hyponatremia is common and can lead to serious consequences in TBI patients. Adequate monitoring and treatment are therefore important. Older patients and those with more significant injury on CT are more at risk.

Comparison of executive functions and functional outcome between older patients with traumatic brain injury and normal older controls.

CONTEXT: The aim of this preliminary study was to assess the impact of traumatic brain injury (TBI) in older age on executive functioning and on their functional outcome. We also aimed to explore the influence of cognitive reserve (CR) and estimated premorbid cognitive functioning (EPCF) on these components. METHODS: A neuropsychological and functional assessment that included tests measuring Inhibition, Updating and Shifting, and functional outcome was administered to 29 patients who sustained a mild or moderate TBI in older age and a group of 24 healthy older participants. CR (level of education) and EPCF variables collected in the TBI group were associated with executive function performance and functional outcome. RESULTS: Patients with TBI obtained significantly worse performances on the spatial working memory (WM) task-reverse condition, and on the completion time of the Trails A and B than the control group. The TBI group also obtained worse functional outcome scores. A higher level of education was associated with better WM performance, and higher estimated premorbid cognitive functioning was associated with better functional outcome post TBI. CONCLUSIONS: Further studies with a larger sample should be conducted to better understand the profile and determinants of recovery from TBI in the elderly.

Longitudinal recovery of executive functions and social participation prediction following traumatic brain injury.

There is heterogeneity across studies and a lack of knowledge about recovery of EFs over time following traumatic brain injury (TBI). Also, EFs are associated with functional outcome, but there is still a gap in knowledge concerning the association between EFs and social participation following TBI. For this reason, we aim to (1) measure the recovery of the three executive function subcomponents of Miyake's model, namely flexibility, updating and inhibition between the acute phase (T1) and 6 months post TBI (T2) and (2) measure the relationship between EFs and social participation after TBI. Thus, a prospective longitudinal study that included 75 patients with TBI (mild and moderate-severe) and 50 patients with orthopedic injuries (controls) without brain damage was carried out. An extensive EFs test battery was administered at T1 and T2 whereas the Mayo-Portland Adaptability Inventory-4 (MPAI-4) was administered only at T2. In contrast with the controls, both TBI groups improved significantly between T1 and T2 on WMS-III Mental Control test (MC) and the D-KEFS Category Switching Condition of the Verbal Fluency task (SVF). Results also showed a simple time effect for the WAIS-IV Digit span and the Hayling tests. Moreover, there was an association between the SVF test and social participation (MPAI-4) at T2. In conclusion, the MC and SVF tests were found to be the best tools for measuring recovery of EFs following TBI. The SVF test was the most likely measure of EFs to give the neuropsychologist an idea of the patient's social participation.

Pitch and Rhythm Perception and Verbal Short-Term Memory in Acute Traumatic Brain Injury.

Music perception deficits are common following acquired brain injury due to stroke, epilepsy surgeries, and aneurysmal clipping. Few studies have examined these deficits following traumatic brain injury (TBI), resulting in an under-diagnosis in this population. We aimed to (1) compare TBI patients to controls on pitch and rhythm perception during the acute phase; (2) determine whether pitch and rhythm perception disorders co-occur; (3) examine lateralization of injury in the context of pitch and rhythm perception; and (4) determine the relationship between verbal short-term memory (STM) and pitch and rhythm perception. Music perception was examined using the Scale and Rhythm tests of the Montreal Battery of Evaluation of Amusia, in association with CT scans to identify lesion laterality. Verbal short-term memory was examined using Digit Span Forward. TBI patients had greater impairment than controls, with 43% demonstrating deficits in pitch perception, and 40% in rhythm perception. Deficits were greater with right hemisphere damage than left. Pitch and rhythm deficits co-occurred 31% of the time, suggesting partly dissociable networks. There was a dissociation between performance on verbal STM and pitch and rhythm perception 39 to 42% of the time (respectively), with most individuals (92%) demonstrating intact verbal STM, with impaired pitch or rhythm perception. The clinical implications of music perception deficits following TBI are discussed.

Recurrent Traumatic Brain Injury Surveillance Using Administrative Health Data: A Bayesian Latent Class Analysis.

Background: The initial injury burden from incident TBI is significantly amplified by recurrent TBI (rTBI). Unfortunately, research assessing the accuracy to conduct rTBI surveillance is not available. Accurate surveillance information on recurrent injuries is needed to justify the allocation of resources to rTBI prevention and to conduct high quality epidemiological research on interventions that mitigate this injury burden. This study evaluates the accuracy of administrative health data (AHD) surveillance case definitions for rTBI and estimates the 1-year rTBI incidence adjusted for measurement error. Methods: A 25% random sample of AHD for Montreal residents from 2000 to 2014 was used in this study. Four widely used TBI surveillance case definitions, based on the International Classification of Disease and on radiological exams of the head, were applied to ascertain suspected rTBI cases. Bayesian latent class models were used to estimate the accuracy of each case definition and the 1-year rTBI measurement-error-adjusted incidence without relying on a gold standard rTBI definition that does not exist, across children (<18 years), adults (18-64 years), and elderly (> =65 years). Results: The adjusted 1-year rTBI incidence was 4.48 (95% CrI 3.42, 6.20) per 100 person-years across all age groups, as opposed to a crude estimate of 8.03 (95% CrI 7.86, 8.21) per 100 person-years. Patients with higher severity index TBI had a significantly higher incidence of rTBI compared to patients with lower severity index TBI. The case definition that identified patients undergoing a radiological examination of the head in the context of any traumatic injury was the most sensitive across children [0.46 (95% CrI 0.33, 0.61)], adults [0.79 (95% CrI 0.64, 0.94)], and elderly [0.87 (95% CrI 0.78, 0.95)]. The most specific case definition was the discharge abstract database in children [0.99 (95% CrI 0.99, 1.00)], and emergency room visits claims in adults/elderly [0.99 (95% CrI 0.99, 0.99)]. Median time to rTBI was the shortest in adults (75 days) and the longest in children (120 days). Conclusion: Conducting accurate surveillance and valid epidemiological research for rTBI using AHD is feasible when measurement error is accounted for.

Early reading comprehension and speed of reading impairments in individuals with uncomplicated and complicated mild traumatic brain injury.

PURPOSE: Several studies have investigated cognitive-communication disorders affecting oral expression skills following TBI but very few have dealt with reading comprehension abilities. The current study aims to measure reading comprehension and speed of reading in adults with uncomplicated and complicated mild traumatic brain injury (TBI) and to determine which demographic and TBI-related variables are predictive of their performance. METHOD: The performances of three groups of participants were compared on the Chapman-Cook Speed of Reading Test (CCSRT). The CCSRT was administered in an acute care setting to 85 hospitalized participants with mild TBI showing traumatic cerebral lesions (complicated mild TBI), to 15 hospitalized participants with uncomplicated mild TBI (no cerebral lesions) and to 68 adults without TBI. Linear regression analyses were performed to determine which variables among sex, age, education, TBI severity (measured by the Glasgow Coma Scale score), speed of processing skills, and site of cerebral lesions significantly predicted CCSRT performances. RESULTS: The control group showed a lower percentage of errors than both TBI groups. On the total score of the CCSRT, the uncomplicated and complicated TBI groups performed worse than the control group. Moreover, as age and speed of processing skills increased, and education decreased, the odds of having a lower score on the CCSRT increased. CONCLUSION: These findings suggest that reading abilities are compromised after mild TBI. Furthermore, the CCSRT may be a useful bedside tool for clinicians who work with individuals with mild TBI.

Dural Venous Sinus Thrombosis in Patients Presenting with Blunt Traumatic Brain Injuries and Skull Fractures: A Systematic Review and Meta-Analysis.

BACKGROUND: Dural venous sinus thrombosis (DVST) is an increasingly recognized complication of blunt traumatic brain injury (TBI) and skull fractures. However, data concerning epidemiology and clinical significance of DVST are unclear. Determining the disease burden in patients with TBI is an important first step to guide future studies assessing the natural course of traumatic DVST or the effects of its treatment. Therefore, we performed to our knowledge the first systematic review and meta-analysis evaluating the prevalence of DVST in patients with TBI and skull fractures. METHODS: MEDLINE and Embase databases were systematically searched for relevant studies published up to March 2018. All studies that assessed the prevalence of DVST among patients with TBI who underwent a vascular imaging study were included. The primary outcome was the presence or absence of DVST on imaging. A random-effects meta-analysis was used to pool studies. RESULTS: Our systematic review yielded 638 articles, and 13 articles met inclusion criteria. In patients with skull fractures adjacent to a venous sinus, the prevalence was 26.2% (95% confidence interval = 19.4%-34.4%). This elevated risk was similar between adult (pooled estimate 23.8%; 95% CI = 16.2%-33.5%) and pediatric (pooled estimate 31.3%; 95% CI = 19.1%-46.9%) populations. CONCLUSIONS: We found an unexpectedly high and consistent frequency of DVST among patients with skull fractures regardless of age group or severity of brain injury. These findings are important and highlight the need for further understanding the natural history of DVST and providing better guidelines on its management.

Clinical Characterization of Traumatic Acute Interhemispheric Subdural Hematoma.

OBJECT: Interhemispheric subdural hematomas (IHSDHs) are thought to be rare. Surgical management of these lesions presents a challenge as they are in close proximity to the sagittal sinus and bridging veins. IHSDHs are poorly characterized clinically and their exact incidence is unknown. There are also no clear guidelines for the management of IHSDH. METHODS: This is a retrospective review of all admitted patients with a diagnosis of traumatic brain injury over a 4-year period at a Level I trauma centre. Clinical characteristics of all patients with subdural hematoma (SDH) and IHSDH were collected. RESULTS: Of 2165 admissions, 1182 patients had acute traumatic SDHs, 420 patients had IHSDHs (1.9% of admissions and 35.5% of SDH), 35 (8.3% of IHSDH) were ≥8 mm in width. IHSDH was isolated in 16 (3.8%) of the cases. Average age was 61.7 ± 21.5 years for all IHSDHs and 77.1 ± 10.4 for large IHSDH (p < 0.001). For large IHSDH, a transient loss of consciousness (LOC) occurred in 51.5% of individuals, post-traumatic amnesia (PTA) in 47.8% of cases, and motor weakness in 37.9% of patients. Five of the large IHSDH patients presented with motor deficits directly related to the IHSDH, and weakness resolved in four of these five individuals. None were treated surgically. Progression of IHSDH width occurred in one patient. CONCLUSION: IHSDHs are often referred to as rare entities. Our results show they are common. Conservative management is appropriate to manage most IHSDHs, as most resolve spontaneously, and their symptoms resolve as well.

Optimal Bone Flap Size for Decompressive Craniectomy for Refractory Increased Intracranial Pressure in Traumatic Brain Injury: Taking the Patient's Head Size into Account.

BACKGROUND: Decompressive craniectomy (DC) is a widely used treatment for refractory high intracranial pressure (ICP). While the Brain Trauma Foundation guidelines favor large DC, there remains a lack of consensus regarding the optimal size of DC in relationship to the patient's head size. The aim of this study is to determine the optimal size of DC to effectively control refractory ICP in traumatic brain injury and to measure that size with a method that takes into consideration the patient's head size. METHODS: All cases of unilateral DC performed to control refractory increased ICP due to cerebral edema during a 7½-year period were included. Demographic and injury-related data were collected by retrospective chart review. The patients were categorized in 2 groups: 21 patients with a "small flaps" and 9 patients with a "large flap." RESULTS: Two groups had similar preoperative characteristics. The amount of cerebrospinal fluid drained and the doses of hyperosmolar therapy given were not different between the 2 groups. The postoperative ICP was significantly lower for the large craniectomy flap group: 13.3 mm Hg confidence interval 99% [12.7, 13.8] versus 16.9 mm Hg confidence interval 99% [16.5, 17.2] (P = 0.01), and this difference was maintained for 96 hours postoperatively. CONCLUSIONS: Better ICP control was achieved in patients who underwent a large decompressive craniectomy (ratio >65%) when compared with smaller craniectomy sizes. The proposed method of measuring the craniectomy size, to our knowledge, is the first to take into account the patient's head size and can be easily measured intraoperatively.

Fast and Accurate Bacterial Species Identification in Urine Specimens Using LC-MS/MS Mass Spectrometry and Machine Learning.

Fast identification of microbial species in clinical samples is essential to provide an appropriate antibiotherapy to the patient and reduce the prescription of broad-spectrum antimicrobials leading to antibioresistances. MALDI-TOF-MS technology has become a tool of choice for microbial identification but has several drawbacks: it requires a long step of bacterial culture before analysis (≥24 h), has a low specificity and is not quantitative. We developed a new strategy for identifying bacterial species in urine using specific LC-MS/MS peptidic signatures. In the first training step, libraries of peptides are obtained on pure bacterial colonies in DDA mode, their detection in urine is then verified in DIA mode, followed by the use of machine learning classifiers (NaiveBayes, BayesNet and Hoeffding tree) to define a peptidic signature to distinguish each bacterial species from the others. Then, in the second step, this signature is monitored in unknown urine samples using targeted proteomics. This method, allowing bacterial identification in less than 4 h, has been applied to fifteen species representing 84% of all Urinary Tract Infections. More than 31,000 peptides in 190 samples were quantified by DIA and classified by machine learning to determine an 82 peptides signature and build a prediction model. This signature was validated for its use in routine using Parallel Reaction Monitoring on two different instruments. Linearity and reproducibility of the method were demonstrated as well as its accuracy on donor specimens. Within 4h and without bacterial culture, our method was able to predict the predominant bacteria infecting a sample in 97% of cases and 100% above the standard threshold. This work demonstrates the efficiency of our method for the rapid and specific identification of the bacterial species causing UTI and could be extended in the future to other biological specimens and to bacteria having specific virulence or resistance factors.

Antithrombotic agents and traumatic brain injury in the elderly population: hemorrhage patterns and outcomes.

OBJECTIVE: Among the elderly, use of antithrombotics (ATs), antiplatelets (APs; aspirin, clopidogrel), and/or anticoagulants (ACs; warfarin, direct oral ACs [DOACs; dabigatran, rivaroxaban, apixaban]) to prevent thromboembolic events must be carefully weighed against the risk of intracranial hemorrhage (ICH) with trauma. The goal of this study was to assess the risk of sustaining a traumatic brain injury (TBI), ICH, and poorer outcomes in relation to AT use among all patients 65 years or older presenting to a single institution with head trauma. METHODS: Data were collected from all head trauma patients 65 years or older presenting to the authors' supraregional tertiary trauma center over a 24-month period and included age, sex, injury mechanism, medical history, international normalized ratio, Glasgow Coma Scale (GCS) score, ICH presence and type, hospital admission, reversal therapy, surgery, discharge destination, Extended Glasgow Outcome Scale (GOSE) score at discharge, and mortality. RESULTS: A total of 1365 head trauma patients 65 years or older were included; 724 were on AT therapy (413 on APs, 151 on ACs, 59 on DOACs, 48 on 2 APs, 38 on AP+AC, and 15 on AP+DOAC) and 641 were not. Among all head trauma patients, the risk of sustaining a TBI was associated with AP use after adjusting for covariates. Of the 731 TBI patients, those using ATs had higher rates of ICH (p <0.0001), functional dependency at discharge (GOSE score ≤ 4; p < 0.0001), and mortality (p < 0.0001). Elevated rates of ICH progression on follow-up CT scanning were observed in patients in the warfarin monotherapy (OR 5.30, p < 0.0001) and warfarin + AP (OR 6.15, p = 0.0011). Risk of mortality was not associated with single antiplatelet use but was notably high with 2 APs (OR 4.66, p = 0.0056), warfarin (OR 5.18, p = 0.0003), and DOAC use (OR 5.09, p = 0.0149). CONCLUSIONS: Elderly trauma patients on ATs, especially combination therapy, are at elevated risk of ICH and poor outcomes compared with those not on AT therapy. While both AP and warfarin use alone and in combination were associated with significantly elevated odds of sustaining an ICH among TBI patients, only warfarin use was a predictor of hemorrhage progression on follow-up scans. The use of a single AP was not associated with mortality; however, the combination of both aspirin and clopidogrel was. Warfarin and DOAC users had comparable mortality rates; however, DOAC users had lower rates of ICH progression, and fewer survivors were functionally dependent at discharge than were warfarin users. DOACs are an overall safer alternative to warfarin for patients at high risk of falls.

Frontal assessment battery (FAB) performance following traumatic brain injury hospitalized in an acute care setting.

The Frontal Assessment Battery (FAB) has been shown to be useful in several clinical settings. The aim of the present study was to examine the performance of patients with traumatic brain injury (TBI) on the FAB and to predict their acute outcome. The FAB was administered to 89 patients with mild (27 = uncomplicated and 39 = complicated) and moderate (n = 23) TBI during hospitalization in an acute care setting. The length of stay in days (LOS), Glasgow Outcome Scale-Revised score (GOSE) and Disability Rating Scale (DRS) score were collected. Results showed no significant differences between the three groups on the FAB score, but age and education were significantly associated with the FAB score. Parietal lesions were associated with lower total FAB score, and with the Similarities, Motor series and Conflicting instructions subscales, while frontal lesions were associated with lower performance on the Motor series and Conflicting instructions subscales. Total FAB score was significantly correlated with all outcome measures, and together the FAB total score and the Glasgow Coma Scale (GCS) score explained 30.8% of the variance in the DRS score. The FAB may be useful clinically to acutely assess frontal and parietal lobe functions at bedside in patients with TBI and, in combination with the GCS score to measure TBI severity, can enable clinicians to predict early outcome.

Effect of Intrawound Vancomycin on Surgical Site Infections in Nonspinal Neurosurgical Procedures: A Systematic Review and Meta-Analysis.

BACKGROUND: Applying vancomycin into the surgical site has been well-described in spinal neurosurgery, with extensive institutional experience and systematic reviews describing its effectiveness in reducing surgical site infections (SSIs). Its use in nonspinal neurosurgical procedures is a logical extension of those findings; however, recent studies have described varying degrees of success. We have summarized the effect of local vancomycin application on SSIs in nonspinal neurosurgical procedures and describe the quality of the supporting evidence. METHODS: MEDLINE, Embase, and Google Scholar were searched through June 2018. Information on study design, demographic data, exposure, and outcomes was extracted. The estimates were combined using random-effects models. RESULTS: Our search retrieved 9 studies for quantitative analysis. They assessed vancomycin use in craniotomy, cranioplasty, deep brain stimulator-related procedures, and ventriculoperitoneal shunt surgery. Most of the studies had serious methodological shortcomings that introduced confounding. We found an overall beneficial effect on SSI incidence (odds ratio, 0.25; 95% confidence interval, 0.12-0.52), which was seen across all subspecialties, except for cranioplasty. The use of vancomycin did not result in the emergence of resistant infections or in a significant increase in the proportion of infections caused by gram-negative organisms. CONCLUSIONS: Vancomycin use in nonspinal neurosurgery is not supported by high-quality evidence, limiting the strength of the conclusions that can be drawn on the topic. Nonetheless, we found an overall favorable effect on SSIs (except in the context of cranioplasty), which should be reproduced in a randomized controlled fashion.

Accuracy of Administrative Health Data for Surveillance of Traumatic Brain Injury: A Bayesian Latent Class Analysis.

BACKGROUND: Traumatic brain injury surveillance provides information for allocating resources to prevention efforts. Administrative data are widely available and inexpensive but may underestimate traumatic brain injury burden by misclassifying cases. Moreover, previous studies evaluating the accuracy of administrative data surveillance case definitions were at risk of bias by using imperfect diagnostic definitions as reference standards. We assessed the accuracy (sensitivity/specificity) of traumatic brain injury surveillance case definitions in administrative data, without using a reference standard, to estimate incidence accurately. METHODS: We used administrative data from a 25% random sample of Montreal residents from 2000 to 2014. We used hierarchical Bayesian latent class models to estimate the accuracy of widely used traumatic brain injury case definitions based on the International Classification of Diseases, or on head radiologic examinations, covering the full injury spectrum in children, adults, and the elderly. We estimated measurement error-adjusted age- and severity-specific incidence. RESULTS: The adjusted traumatic brain injury incidence was 76 (95% CrI = 68, 85) per 10,000 person-years (underestimated as 54 [95% CrI = 54, 55] per 10,000 without adjustment). The most sensitive case definitions were radiologic examination claims in adults/elderly (0.48; 95% CrI = 0.43, 0.55 and 0.66; 95% CrI = 0.54, 0.79) and emergency department claims in children (0.45; 95% CrI = 0.39, 0.52). The most specific case definitions were inpatient claims and discharge abstracts (0.99; 95% CrI = 0.99, 1.00). We noted strong secular trends in case definition accuracy. CONCLUSIONS: Administrative data remain a useful tool for conducting traumatic brain injury surveillance and epidemiologic research when measurement error is adjusted for.

CT Perfusion to Guide Placement of Invasive Cerebral Perfusion Monitor in Subarachnoid Hemorrhage Induced Vasospasm.

BACKGROUND: Vasospasm is a challenging component of the subarachnoid hemorrhage "syndrome" that is unpredictable and very difficult to monitor using noninvasive or invasive monitoring technologies in neurocritical units. METHODS: We describe the novel use of computerized tomography perfusion (CTP) imaging to choose proper targets for invasive cerebral blood flow monitors. RESULTS: A total of 3 patients are included in this report. CTP parameters were used to generate points of interest to target using invasive cerebral monitoring of the cerebral blood flow and initiate vasodilator therapy and subsequently guide its weaning. CONCLUSIONS: CTP can be useful in localizing a specific anatomical target for invasive monitoring in subarachnoid hemorrhage patients suffering from vasospasm.