Is delayed fixation worthwhile in patients with long bone fracture concomitant with mild traumatic brain injury? A propensity score-matched study.

INTRODUCTION: Early definite treatment for orthopedic patients is strongly advocated. However, a consensus has not been reached on the optimal timing of long bone fracture fixation for patients with associated mild traumatic brain injury (TBI). Surgeons lack evidence on the basis on which they should decide on the operation timing. METHODS: We retrospectively reviewed the data of patients with mild TBI and lower extremity long bone fractures from 2010 to 2020. The patients receiving internal fixation within and after 24 h were defined as the early- and delayed-fixation groups. We compared the discharge Glasgow Coma Scale (GCS) scores, lengths of stay, and in-hospital complications. Propensity score matching (PSM) with multiple adjusted variables and a 1:1 matching ratio was applied to reduce selection bias. RESULTS: In total, 181 patients were enrolled; 78 (43.1%) and 103 (56.9%) patients received early and delayed fracture fixation, respectively. After matching, each group had 61 participants and were statistically identical. The delayed group did not have better discharge GCS scores (early vs. delayed: 15.0 ± 0 vs. 15.0 ± 0.1; p = 0.158). The groups did not differ in their lengths of hospital stay (15.3 ± 10.6 vs. 14.8 ± 7.9; p = 0.789), intensive care unit stay (2.7 ± 4.3 vs. 2.7 ± 3.8; p = 0.947), or incidence of complications (23.0% vs. 16.4%; p = 0.494). CONCLUSIONS: Delayed fixation for patients with lower extremity long bone fractures concurrent with mild TBI does not result in fewer complications or improved neurologic outcomes compared with early fixation. Delaying fixation may not be necessary to prevent the second hit phenomenon and has not demonstrated any clear benefits.

Toward rational use of repeat imaging in children with mild traumatic brain injuries and intracranial injuries.

OBJECTIVE: Limited evidence exists on the utility of repeat neuroimaging in children with mild traumatic brain injuries (mTBIs) and intracranial injuries (ICIs). Here, the authors identified factors associated with repeat neuroimaging and predictors of hemorrhage progression and/or neurosurgical intervention. METHODS: The authors performed a multicenter, retrospective cohort study of children at four centers of the Pediatric TBI Research Consortium. All patients were ≤ 18 years and presented within 24 hours of injury with a Glasgow Coma Scale score of 13-15 and evidence of ICI on neuroimaging. The outcomes of interest were 1) whether patients underwent repeat neuroimaging during index admission, and 2) a composite outcome of progression of previously identified hemorrhage ≥ 25% and/or repeat imaging as an indication for subsequent neurosurgical intervention. The authors performed multivariable logistic regression and report odds ratios and 95% confidence intervals. RESULTS: A total of 1324 patients met inclusion criteria; 41.3% of patients underwent repeat imaging. Repeat imaging was associated with clinical change in 4.8% of patients; the remainder of the imaging tests were for routine surveillance (90.9%) or of unclear prompting (4.4%). In 2.6% of patients, repeat imaging findings were reported as an indication for neurosurgical intervention. While many factors were associated with repeat neuroimaging, only epidural hematoma (OR 3.99, 95% CI 2.22-7.15), posttraumatic seizures (OR 2.95, 95% CI 1.22-7.41), and age ≥ 2 years (OR 2.25, 95% CI 1.16-4.36) were significant predictors of hemorrhage progression and/or neurosurgery. Of patients without any of these risk factors, none underwent neurosurgical intervention. CONCLUSIONS: Repeat neuroimaging was commonly used but uncommonly associated with clinical deterioration. Although several factors were associated with repeat neuroimaging, only posttraumatic seizures, age ≥ 2 years, and epidural hematoma were significant predictors of hemorrhage progression and/or neurosurgery. These results provide the foundation for evidence-based repeat neuroimaging practices in children with mTBI and ICI.

Pediatric Mild Traumatic Brain Injury: Who Can Be Managed at a Non-pediatric Trauma Center Hospital? A Systematic Review of the Literature.

BACKGROUND: Pediatric traumatic brain injury (TBI) affects about 475,000 children in the United States annually. Studies from the 1990s showed worse mortality in pediatric TBI patients not transferred to a pediatric trauma center (PTC), but did not examine mild pediatric TBI. Evidence-based guidelines used to identify children with clinically insignificant TBI who do not require head CT were developed by the Pediatric Emergency Care Applied Research Network (PECARN). However, which patients can be safely observed at a non-PTC is not directly addressed. METHODS: A systematic review of the literature was conducted, focusing on management of pediatric TBI and transfer decisions from 1990 to 2020. RESULTS: Pediatric TBI patients make up a great majority of preventable transfers and admissions, and comprise a significant portion of avoidable costs to the health care system. Majority of mild TBI patients admitted to a PTC following transfer do not require ICU care, surgical intervention, or additional imaging. Studies have shown that as high as 83% of mild pediatric TBI patients are discharged within 24 hrs. CONCLUSIONS: An evidence-based clinical practice algorithm was derived through synthesis of the data reviewed to guide transfer decision. The papers discussed in our systematic review largely concluded that transfer and admission was unnecessary and costly in pediatric patients with mild TBI who met the following criteria: blunt, no concern for NAT, low risk on PECARN assessment, or intermediate risk on PECARN with negative imaging or imaging with either isolated, nondisplaced skull fractures without ICH and/or EDH, or SDH <0.3 cm with no midline shift.

Predictors of neurosurgical intervention in complicated mild traumatic brain injury patients: a retrospective cohort study.

OBJECTIVES: To determine the predicting demographic, clinical and radiological factors for neurosurgical intervention in complicated mild traumatic brain injury (mTBI) patients. METHODS: Design: retrospective multicenter cohort study. Participants: patients aged ≥16 presenting to all level-I trauma centers in Quebec between 09/2016 and 12/2017 with mTBI(GCS 13-15) and complication on initial head CT (intracranial hemorrhage/skull fracture). Procedure: Consecutive medical records were reviewed and separated into two groups: no neurosurgical intervention and neurosurgical intervention (NSI). Main outcome: neurosurgical intervention. Analysis: multiple logistic regression model. RESULTS: Four hundred and seventy-eight patients were included and 40 underwent NSI. One patient had radiological deterioration but no clinical deterioration prior to surgery. Subdural hemorrhage ≥4 mm width (OR:3.755 [95% CI:1.290-10.928]) and midline shift (OR:7.507 [95% CI: 3.317-16.989]) increased the risk of NSI. Subarachnoid hemorrhage was associated with a lower risk of NSI (OR:0.312 [95% CI: 0.136-0.713]). All other intracranial hemorrhages were not associated with NSI. CONCLUSION: Radiological deterioration was not associated with the incidence of NSI. Subdural hemorrhage and midline shift should be predicting factors for neurosurgery. Some patients with isolated findings such as subarachnoid hemorrhage could be safely managed in their original center without being transferred to a level-I trauma center.

Therapeutic Effect of Aerobic Exercise for Adolescents After Mild Traumatic Brain Injury and Sport-Related Concussion: A Meta-Analysis from Randomized Controlled Trials.

BACKGROUND: We searched PubMed, Embase, and the Cochrane Library for randomized controlled trials from January 1980 to April 2018 for adolescents with mild traumatic brain injury (mTBI) to explore the value of aerobic exercise in sport-related concussion (SRC) and mTBI treatment. METHODS: A meta-analysis for the postconcussion symptom scale (PCSS) score and time to recovery was performed with STATA software. RESULTS: We found that aerobic exercise versus usual treatment significantly decreased the PCSS score (weighted mean difference = 6.51, 95% confidence interval: 0.29, 12.72; P = 0.040), as well as the time to recovery (weighted mean difference = -3.87; 95% confidence interval: -6.50, -1.23; P = 0.004). However, aerobic exercise showed no significant improvement in immediate postconcussion assessment and cognitive testing (P = 0.471/0.129/0.648/0.800, respectively, in verbal memory, visual memory, visual motor speed, and reaction time). CONCLUSIONS: Compared with usual treatment, aerobic exercise promoted mTBI adolescents' recovery, assessed by PCSS and time to recovery. However, aerobic exercise may not help with neurocognitive function recovery.

Mild traumatic brain injury in children with ventricular shunts: a PREDICT study.

OBJECTIVE: Current clinical decision rules (CDRs) guiding the use of CT scanning in pediatric traumatic brain injury (TBI) assessment generally exclude children with ventricular shunts (VSs). There is limited evidence as to the risk of abnormalities found on CT scans or clinically important TBI (ciTBI) in this population. The authors sought to determine the frequency of these outcomes and the presence of CDR predictor variables in children with VSs. METHODS: The authors undertook a planned secondary analysis on children with VSs included in a prospective external validation of 3 CDRs for TBI in children presenting to 10 emergency departments in Australia and New Zealand. They analyzed differences in presenting features, management and acute outcomes (TBI on CT and ciTBI) between groups with and without VSs, and assessed the presence of CDR predictors in children with a VS. RESULTS: A total of 35 of 20,137 children (0.2%) with TBI had a VS; only 2 had a Glasgow Coma Scale score < 15. Overall, 49% of patients with a VS underwent CT scanning compared with 10% of those without a VS. One patient had a finding of TBI on CT scanning, with positive predictor variables on CDRs. This patient had a ciTBI. No patient required neurosurgery. For children with and without a VS, the frequency of ciTBI was 2.9% (95% CI 0.1%-14.9%) compared with 1.4% (95% CI 1.2%-1.6%) (difference 1.5% [95% CI -4.0% to 7.0%]), and TBI on CT 2.9% (95% CI 0.1%-14.9%) compared with 2.0% (95% CI 1.8%-2.2%) (difference 0.9%, 95% CI -4.6% to 6.4%). CONCLUSIONS: The authors' data provide further support that the risk of TBI is similar for children with and without a VS.

Development of clinical decision rules for traumatic intracranial injuries in patients with mild traumatic brain injury in a developing country.

BACKGROUND: The majority of clinical decision rules for prediction of intracranial injury in patients with mild traumatic brain injury (TBI) were developed from high-income countries. The application of these rules in low or middle-income countries, where the primary mechanism of injury was traffic accidents, is questionable. METHODS: We developed two practical decision rules from a secondary analysis of a multicenter, prospective cohort of 1,164 patients with mild TBI who visited the emergency departments from 2013 to 2016. The clinical endpoints were the presence of any intracranial injury on CT scans and the requirement of neurosurgical interventions within seven days of onset. RESULTS: Thirteen predictors were included in both models, which were age ≥60 years, dangerous mechanism of injury, diffuse headache, vomiting >2 episodes, loss of consciousness, posttraumatic amnesia, posttraumatic seizure, history of anticoagulant use, presence of neurological deficits, significant wound at the scalp, signs of skull base fracture, palpable stepping at the skull, and GCS <15 at 2 hours. For the model-based score, the area under the receiver operating characteristic curve (AuROC) was 0.85 (95%CI 0.82, 0.87) for positive CT results and 0.87 (95%CI 0.83, 0.91) for requirement of neurosurgical intervention. For the clinical-based score, the AuROC for positive CT results and requirement of neurosurgical intervention was 0.82 (95%CI 0.79, 0.85) and 0.84 (95%CI 0.80, 0.88), respectively. CONCLUSIONS: The models delivered good calibration and excellent discrimination both in the development and internal validation cohort. These rules can be used as assisting tools in risk stratification of patients with mild TBI to be sent for CT scans or admitted for clinical observation.

Influence of Simulated Pre-Hospital Transport, Time to Analysis, and Storage Temperature on S100 Calcium-Binding Protein B Values.

According to in-hospital guidelines, the biomarker, S100 calcium-binding protein B (S100B), is used to rule out intracranial lesions in mild-moderate traumatic brain injury (TBI). It is currently investigated whether S100B is applicable in a pre-hospital setting. The aim was to compare S100B values and hemolysis index in blood samples drawn and stored under simulated pre-hospital conditions to standardized blood samples. Thirty patients undergoing craniotomy at Department of Neurosurgery, Aarhus University Hospital (Aarhus, Denmark) each had six blood samples drawn. Two samples, drawn in in-hospital standardized Beckton Dickinson tubes and pre-hospital Monovette tubes, respectively, were stored as references at 21°C for 30 min. Two samples were stored at 15°C and 29°C, respectively, one sample was stored at prolonged time (60 min), and one sample was transported for 30 min before centrifugation. S100B values were compared by equivalence test with a pre-defined equivalence margin of ±8.5%. There was no clinically relevant difference between samples stored in different tubes, at various temperatures, or time to analysis compared to reference samples. Transported samples had an 11.5% (90% confidence interval [CI], 6.55; 16.61) higher median S100B value and a 430% (95% CI, 279.6; 661.4) higher median hemolysis index compared to reference samples. Three of 30 (10%) patients had an S100B value above guideline cutoff in the transported sample, which was not found in reference samples (false positive). There were no false negatives. In conclusion, S100B values were not influenced by different tubes, temperatures, and time to analysis. Transported samples had higher median S100B values and hemolysis, icterus, and lipemia index compared to reference samples.

Can the "important brain injury criteria" predict neurosurgical intervention in mild traumatic brain injury? A validation study.

BACKGROUND: There is variability in the management of patients presenting to the emergency department (ED) with mild traumatic brain injury (MTBI) and abnormal findings on their initial head computed tomography (CT). The main objective of this study was to validate the value of the Important Brain Injury (IBI) criteria, introduced by the Canadian CT-Head Rule, in predicting the need for surgical intervention. The secondary objective was to identify independent predictors for neurosurgical intervention. METHODS: This is a post hoc analysis of a prospective cohort of adult patients presenting to the ED of one tertiary care, academic center, between 2008 and 2012, with MTBI and an abnormal initial head CT. Neurosurgical intervention was at the discretion of the treating physician. The sensitivity and specificity of the IBI criteria were calculated with 95% confidence intervals (CI95%). A multivariate logistic regression model was used to identify independent predictors for neurosurgical intervention with the direct entry method. RESULTS: A total of 678 patients (male = 65.9%, mean age = 62.5 years) were included, of whom 114 (16.8%) required neurosurgical intervention. All patients requiring neurosurgical intervention met IBI criteria on their initial head CT (sensitivity of 100% [CI95% 96.8-100]). However, 368 (65.2%) patients with findings of IBI did not require neurosurgical intervention (specificity of 34.8% [CI95% 30.8-38.8]). Age over 65 was independently associated with neurosurgical intervention in the IBI population. CONCLUSION: The IBI criteria for MTBI identified all patients who required neurosurgical intervention; however its specificity is low.

Perioperative Considerations in Patients With Concussion.

Concussions affect the normal functioning of the autonomic nervous system and glucose metabolism, impair cerebral autoregulation to Paco2, and produce abnormal variances in myogenic and vagal tone. Because anesthesia also has an impact on these same processes, it is vital to delineate the best practice in the perianesthesia period to minimize additional damage to the concussed brain. There are currently no practice guidelines surrounding perianesthesia management of patients with concussion to guide practice. To answer 4 clinically pertinent questions for nurse anesthesia practice, the authors completed a literature review. Articles obtained from the search that were identified as randomized controlled trials, systematic reviews, or integrative reviews were evaluated for relevance to clinical practice. Many of the literature recommendations emphasize the prevention of secondary neurologic injury. Optimal outcomes are believed to best align with careful attention to mean arterial pressures and Paco2 to prevent global hypoperfusion. The impact of particular anesthetic agents on concussion injuries is unknown. Major advances in neuroimaging, biomarker identification, and technology have occurred. However, further research is needed to identify evidence-based interventions for managing patients after concussion requiring anesthesia.

A Rapid Neurological Assessment Protocol for Repeated Mild Traumatic Brain Injury in Awake Rats.

Preclinical models for mild traumatic brain injury (mTBI) need to recapitulate several essential clinical features associated with mTBI, including a lack of significant neuropathology and the onset of neurocognitive symptoms normally associated with mTBI. Here we show how to establish a protocol for reliably and repeatedly inducing a mild awake closed head injury (ACHI) in rats, with no mortality or clinical indications of persistent pain. Moreover, we implement a new rapid neurological assessment protocol (NAP) that can be completely conducted within 1 min of each impact. This ACHI model will help to rectify the paucity of data on how repeated mTBI (r-mTBI) impacts the juvenile brain, an area of significant concern in clinical populations where there is evidence that behavioral sequelae following injury can be more persistent in juveniles. In addition, the ACHI model can help determine if r-mTBI early in life can predispose the brain to exhibiting greater neuropathology (i.e., chronic traumatic encephalopathy) later in life and can facilitate the identification of critical periods of vulnerability to r-mTBI across the lifespan. This article describes the protocol for administering an awake closed head mTBI (i.e., ACHI) to rats, as well as how to perform a rapid NAP following each ACHI. Methods for administering the ACHI to individual subjects repeatedly are described, as are the methods and scoring system for the NAP. The goal of this article is to provide a standardized set of procedures allowing the ACHI and NAP protocols to be used reliably by different laboratories. © 2019 by John Wiley & Sons, Inc.

Intracranial arachnoid cyst rupture after mild TBI in children: have we underestimated this risk?

The association between intracranial arachnoid cyst rupture and mild brain trauma is infrequently reported. The purpose of this case report is to describe the case of a child with a left temporal arachnoid cyst who suffered rupture with haemorrhage after mild trauma during a football match. The child presented with chronic headache of mild intensity that progressed to a more intense headache after a traumatic event. He underwent surgical intervention after diagnosis of chronic haemorrhage in an arachnoid cyst in the ipsilateral subdural space. The risk of intracranial arachnoid cyst rupture should be considered during the evaluation of oligosymptomatic patients because it is a potentially catastrophic event.

Intracranial pressure management and neurological outcome for patients with mild traumatic brain injury who required neurosurgical intervention: a Japanese database study.

Purpose: Among mild traumatic brain injuries (mTBI; a Glasgow Coma Scale score ≥13 on arrival), few result in severe neurological deficit, especially when they needed neurosurgical intervention. We investigated the association of intracranial pressure (ICP) control management with neurological outcome in patients with mTBI who needed neurosurgical intervention. Methods: From 1,092 records of the Japan Neurotrauma Data Bank during 2009-2011, we retrospectively identified 195 patients with neurosurgical intervention for mTBI. Using the Glasgow Outcome Scale, we grouped records into two: favorable and poor outcome. We analyzed neurological outcomes using a logistic regression analysis adjusted for ICP control managements. Results: Seventy patients had a poor outcome. Logistic regression analysis revealed that sedatives, hyperosmotic agents, and hyperventilation therapy were significantly associated with poor outcome (odds ratio [OR]: 2.36, 95% confidence interval [CI]: 1.31-4.26; OR: 2.81, 95% CI: 1.17-6.75; OR: 9.36, 95% CI: 1.81-48.35). However, temperature management was significantly related with favorable outcome (OR: 0.26, 95% CI: 0.10-0.66). Conclusions: Our study, using a Japanese multicenter brain trauma registry, suggested that requirement of sedatives, hyperosmotic agents, and hyperventilation is associated with poor neurological outcome for patients with mTBI who underwent neurosurgical intervention, although temperature management was associated with favorable neurological outcome.

Three­time point view of mild brain injuries' structural alteration and their association with cognitive domains.

BACKGROUND: Mild traumatic brain injury (mTBI) accounts for 70­80% of total neurotrauma, majority among them manifest with cognitive deficits. Till date there are few/or no 3­time­point longitudinal studies that have evidenced brain volume changes. The current study has investigated volume changes at 3­time­points and their association with cognitive sequel. METHODS: Twenty­one mTBI patients with normal imaging and 15 GCS were recruited. Initially these patients were evaluated with magnetic resonance imaging (MRI) scan ≤36hours and neuropsychological test (NPT) during 2­3weeks after­injury. All the patients were available for follow­up for repeat MRI and NPT on 3­4 and 6­7months. The imaging and test scores were analyzed using repeated measures of analysis (P<0.05). The brain volumes were correlated with respective test­scores using partial­correlation. RESULTS: Left frontal lobe (P<0.029) and thalamus (P=0.049) showed significant increase in mean volume overtime, whereas corpus callosum (mid­anterior [P=0.011] and central [P=0.04]) and left cerebellum (P=0.043) showed significant decrease in mean volume overtime. Clinically cognitive scores improved with time. Eventual improvements in attention and memory scores were positively associated with increase in cingulate gyrus volume. CONCLUSIONS: The 3­time­point longitudinal study illustrates brain areas that changes with time and their association with improving cognitive scores. The study provides hint about the pattern of natural recovery.

High prevalence of prior contact sports play and concussion among orthopedic and neurosurgical department chairs.

OBJECTIVE Increased understanding of the consequences of traumatic brain injury has heightened concerns about youth participation in contact sports. This study investigated the prevalence of high school and collegiate contact sports play and concussion history among surgical department chairs. METHODS A cross-sectional survey was administered to 107 orthopedic and 74 neurosurgery chairs. Responses were compared to published historical population norms for contact sports (high school 27.74%, collegiate 1.44%), football (high school 10.91%, collegiate 0.76%), and concussion prevalence (12%). One-proportion Z-tests, chi-square tests, and binary logistic regression were used to analyze differences. RESULTS High school contact sports participation was 2.35-fold higher (65.3%, p < 0.001) for orthopedic chairs and 1.73-fold higher (47.9%, p = 0.0018) for neurosurgery chairs than for their high school peers. Collegiate contact sports play was 31.0-fold higher (44.7%, p < 0.001) for orthopedic chairs and 15.1-fold higher (21.7%, p < 0.001) for neurosurgery chairs than for their college peers. Orthopedic chairs had a 4.30-fold higher rate of high school football participation (46.9%, p < 0.001) while neurosurgery chairs reported a 3.05-fold higher rate (33.3%, p < 0.001) than their high school peers. Orthopedic chairs reported a 28.1-fold higher rate of collegiate football participation (21.3%, p < 0.001) and neurosurgery chairs reported an 8.58-fold higher rate (6.5%, p < 0.001) compared to their college peers. The rate at which orthopedic (42.6%, p < 0.001) and neurosurgical (42.4%, p < 0.001) chairs reported having at least 1 concussion in their lifetime was significantly higher than the reported prevalence in the general population. After correction for worst possible ascertainment bias, all results except high school contact sports participation remained significant. CONCLUSIONS The high prevalence of youth contact sports play and concussion among surgical specialty chairs affirms that individuals in careers requiring high motor and cognitive function frequently played contact sports. The association highlights the need to further examine the relationships between contact sports and potential long-term benefits as well as risks of sport-related injury.

Definition of Traumatic Brain Injury, Neurosurgery, Trauma Orthopedics, Neuroimaging, Psychology, and Psychiatry in Mild Traumatic Brain Injury.

Traumatic brain injury (TBI) disrupts the normal function of the brain. This condition can adversely affect a person's quality of life with cognitive, behavioral, emotional, and physical symptoms that limit interpersonal, social, and occupational functioning. Although many systems exist, the simplest classification includes mild, moderate, and severe TBI depending on the nature of injury and the impact on the patient's clinical status. Patients with TBI require prompt evaluation and multidisciplinary management. Aside from the type and severity of the TBI, recovery is influenced by individual patient characteristics, social and environmental factors, and access to medical and rehabilitation services.

Epidemiology of Mild Traumatic Brain Injury with Intracranial Hemorrhage: Focusing Predictive Models for Neurosurgical Intervention.

OBJECTIVE: To outline differences in neurosurgical intervention (NI) rates between intracranial hemorrhage (ICH) types in mild traumatic brain injuries and help identify which ICH types are most likely to benefit from creation of predictive models for NI. METHODS: A multicenter retrospective study of adult patients spanning 3 years at 4 U.S. trauma centers was performed. Patients were included if they presented with mild traumatic brain injury (Glasgow Coma Scale score 13-15) with head CT scan positive for ICH. Patients were excluded for skull fractures, "unspecified hemorrhage," or coagulopathy. Primary outcome was NI. Stepwise multivariable logistic regression models were built to analyze the independent association between ICH variables and outcome measures. RESULTS: The study comprised 1876 patients. NI rate was 6.7%. There was a significant difference in rate of NI by ICH type. Subdural hematomas had the highest rate of NI (15.5%) and accounted for 78% of all NIs. Isolated subarachnoid hemorrhages had the lowest, nonzero, NI rate (0.19%). Logistic regression models identified ICH type as the most influential independent variable when examining NI. A model predicting NI for isolated subarachnoid hemorrhages would require 26,928 patients, but a model predicting NI for isolated subdural hematomas would require only 328 patients. CONCLUSIONS: This study highlighted disparate NI rates among ICH types in patients with mild traumatic brain injury and identified mild, isolated subdural hematomas as most appropriate for construction of predictive NI models. Increased health care efficiency will be driven by accurate understanding of risk, which can come only from accurate predictive models.

The clinical significance of isolated traumatic subarachnoid hemorrhage in mild traumatic brain injury: A meta-analysis.

BACKGROUND: The rates of clinical and radiographic progression and the need for neurosurgical intervention in patients with isolated traumatic subarachnoid hemorrhage (itSAH) after mild traumatic brain injury (Glasgow Coma Scale score, 13-15) has not been well established.The aim of this work was to review the evidence regarding patient outcomes after mild traumatic brain injury with itSAH. METHODS: Two authors independently extracted the data according to a predefined protocol. The proportions of patients who had the outcomes of interest were pooled using random-effects model. The quality of included studies was assessed using the methodological index for nonrandomized studies scale. RESULTS: Thirteen studies reporting on 15,327 patients met inclusion criteria, and outcomes were pooled where available. No patient required neurosurgical intervention on presentation to hospital, and the incidence of need for eventual neurosurgical intervention was 0.0017% (95% confidence interval [CI], 0-0.39%). Moreover, the pooled analyses for all patients with available data showed an incidence of 5.76% (95% CI, 1.18-12.94%) for radiographic progression, 0.75% (95% CI, 0-2.39%) for neurologic deterioration, and 0.60% (95% CI, 0.09-1.41%) for mortality. Only one patient had died due to neurological injury. CONCLUSIONS: These patients experience very low rates of radiographic progression and neurologic deterioration and rarely require neurosurgical intervention or die due to neurological injury. LEVEL OF EVIDENCE: Meta-analysis, level III.