Traumatic brain injury with and without late posttraumatic seizures: what are the impacts in the post-acute phase: a NIDRR Traumatic Brain Injury Model Systems study

Post-Traumatic Epilepsy: Observations from an Urban Level 1 Trauma Center

There are approximately 2.5 million cases of traumatic brain injury (TBI) in the U.S. each year. Post-traumatic epilepsy (PTE), a sequela of TBI, has been shown to occur in approximately 15% of TBI patients. Pre-disposing risk factors for the development of PTE include severe TBI and penetrating head injury. PTE is associated with poor functional outcomes, increased negative social factors, and mental illness. We conducted a retrospective chart review with a 5-year timeframe at an urban Level 1 Trauma Center. Patients with ICD-10-CM codes associated with TBI were identified. Patients were coded as TBI with or without PTE by the presence of codes associated with PTE. Datapoints collected included risk factors for PTE and encounters with neurologists. A total of 1886 TBI patients were identified, with 178 (9.44%) classified as TBI with PTE. The most significant risk factor associated with PTE was severe brain injury, with an odds ratio (OR) of 2.955 (95% CI [2.062,4.236]; p < 0.0001). Only 19 of 178 patients (10.7%) visited a neurologist beyond 6 months after TBI. Our results suggest the presence of a significant population of patients with PTE and the need for better follow-up.

Mortality among veterans with epilepsy: Temporal significance of traumatic brain injury exposure

OBJECTIVE

Epilepsy is associated with significant mortality risk. There is limited research examining how traumatic brain injury (TBI) timing affects mortality in relation to the onset of epilepsy. We aimed to assess the temporal relationship between epilepsy and TBI regarding mortality in a cohort of post-9/11 veterans.

METHODS

This retrospective cohort study included veterans who received health care in the Defense Health Agency and the Veterans Health Administration between 2000 and 2019. For those diagnosed with epilepsy, the index date was the date of first antiseizure medication or first seizure; we simulated the index date for those without epilepsy. We created the study groups by the index date and first documented TBI: (1) controls (no TBI, no epilepsy), (2) TBI only, (3) epilepsy only, (4) TBI before epilepsy, (5) TBI within 6 months after epilepsy, and (6) TBI >6 months after epilepsy. Kaplan-Meier estimates of all-cause mortality were calculated, and log-rank tests were used to compare unadjusted cumulative mortality rates among groups compared to controls. Cox proportional hazard models were used to compute hazard ratios (HRs) with 95% confidence intervals (CIs).

RESULTS

Among 938 890 veterans, 27 436 (2.92%) met epilepsy criteria, and 264 890 (28.22%) had a TBI diagnosis. Mortality was higher for veterans with epilepsy than controls (6.26% vs. 1.12%; p < .01). Veterans with TBI diagnosed ≤6 months after epilepsy had the highest mortality hazard (HR = 5.02, 95% CI = 4.21-5.99) compared to controls, followed by those with TBI before epilepsy (HR = 4.25, 95% CI = 3.89-4.58), epilepsy only (HR = 4.00, 95% CI = 3.67-4.36), and TBI >6 months after epilepsy (HR = 2.49, 95% CI = 2.17-2.85). These differences were significant across groups.

SIGNIFICANCE

TBI timing relative to epilepsy affects time to mortality; TBI within 6 months after epilepsy or before epilepsy diagnosis was associated with earlier time to death compared to those with epilepsy only or TBI >6 months after epilepsy.

Prognostic Implications of Early Prediction in Posttraumatic Epilepsy

Posttraumatic epilepsy (PTE) is a complication of traumatic brain injury that can increase morbidity, but predicting which patients may develop PTE remains a challenge. Much work has been done to identify a variety of risk factors and biomarkers, or a combination thereof, for patients at highest risk of PTE. However, several issues have hampered progress toward fully adapted PTE models. Such issues include the need for models that are well-validated, cost-effective, and account for competing outcomes like death. Additionally, while an accurate PTE prediction model can provide quantitative prognostic information, how such information is communicated to inform shared decision-making and treatment strategies requires consideration of an individual patient's clinical trajectory and unique values, especially given the current absence of direct anti-epileptogenic treatments. Future work exploring approaches integrating individualized communication of prediction model results are needed.

Insights into epileptogenesis from post-traumatic epilepsy

Post-traumatic epilepsy (PTE) accounts for 5% of all epilepsies. The incidence of PTE after traumatic brain injury (TBI) depends on the severity of injury, approaching one in three in groups with the most severe injuries. The repeated seizures that characterize PTE impair neurological recovery and increase the risk of poor outcomes after TBI. Given this high risk of recurrent seizures and the relatively short latency period for their development after injury, PTE serves as a model disease to understand human epileptogenesis and trial novel anti-epileptogenic therapies. Epileptogenesis is the process whereby previously normal brain tissue becomes prone to recurrent abnormal electrical activity, ultimately resulting in seizures. In this Review, we describe the clinical course of PTE and highlight promising research into epileptogenesis and treatment using animal models of PTE. Clinical, imaging, EEG and fluid biomarkers are being developed to aid the identification of patients at high risk of PTE who might benefit from anti-epileptogenic therapies. Studies in preclinical models of PTE have identified tractable pathways and novel therapeutic strategies that can potentially prevent epilepsy, which remain to be validated in humans. In addition to improving outcomes after TBI, advances in PTE research are likely to provide therapeutic insights that are relevant to all epilepsies.

Posttraumatic Epilepsy and Dementia Risk

Importance

Although both head injury and epilepsy are associated with long-term dementia risk, posttraumatic epilepsy (PTE) has only been evaluated in association with short-term cognitive outcomes.

Objective

To investigate associations of PTE with dementia risk.

Design, Setting, and Participants

The Atherosclerosis Risk in Communities (ARIC) study initially enrolled participants from 1987 to 1989 and this prospective cohort study uses data through December 31, 2019, with a median follow-up of 25 years. Data were analyzed between March 14, 2023, and January 2, 2024. The study took place in 4 US communities in Minnesota, Maryland, North Carolina, and Mississippi. Of 15 792 ARIC study participants initially enrolled, 2061 were ineligible and 1173 were excluded for missing data, resulting in 12 558 included participants.

Exposures

Head injury was defined by self-report and International Classification of Diseases (ICD) diagnostic codes. Seizure/epilepsy was defined using ICD codes. PTE was defined as a diagnosis of seizure/epilepsy occurring more than 7 days after head injury. Head injury, seizure/epilepsy, and PTE were analyzed as time-varying exposures.

Main Outcomes and Measures

Dementia was defined using cognitive assessments, informant interviews, and ICD and death certificate codes. Adjusted Cox and Fine and Gray proportional hazards models were used to estimate dementia risk.

Results

Participants had a mean (SD) age of 54.3 (5.8) years at baseline, 57.7% were female, 28.2% were of self-reported Black race, 14.4% were ultimately categorized as having head injury, 5.1% as having seizure/epilepsy, and 1.2% as having PTE. Over a median follow-up of 25 (25th to 75th percentile, 17-30) years, 19.9% developed dementia. In fully adjusted models, compared with no head injury and no seizure/epilepsy, PTE was associated with 4.56 (95% CI, 4.49-5.95) times the risk of dementia, while seizure/epilepsy was associated with 2.61 (95% CI, 2.21-3.07) times the risk and head injury with 1.63 (95% CI, 1.47-1.80) times the risk. The risk of dementia associated with PTE was significantly higher than the risk associated with head injury alone and with nontraumatic seizure/epilepsy alone. Results were slightly attenuated in models accounting for the competing risks of mortality and stroke, but patterns of association remained similar. In secondary analyses, the increased dementia risk associated with PTE occurring after first vs second head injury and after mild vs moderate/severe injury was similar.

Conclusions and Relevance

In this community-based cohort, there was an increased risk of dementia associated with PTE that was significantly higher than the risk associated with head injury or seizure/epilepsy alone. These findings provide evidence that PTE is associated with long-term outcomes and supports both the prevention of head injuries via public health measures and further research into the underlying mechanisms and the risk factors for the development of PTE, so that efforts can also be focused on the prevention of PTE after a head injury.

Epilepsy phenotype and its reproducibility after lateral fluid percussion-induced traumatic brain injury in rats: Multicenter EpiBioS4Rx study project 1

OBJECTIVE

This study was undertaken to assess reproducibility of the epilepsy outcome and phenotype in a lateral fluid percussion model of posttraumatic epilepsy (PTE) across three study sites.

METHODS

A total of 525 adult male Sprague Dawley rats were randomized to lateral fluid percussion-induced brain injury (FPI) or sham operation. Of these, 264 were assigned to magnetic resonance imaging (MRI cohort, 43 sham, 221 traumatic brain injury [TBI]) and 261 to electrophysiological follow-up (EEG cohort, 41 sham, 220 TBI). A major effort was made to harmonize the rats, materials, equipment, procedures, and monitoring systems. On the 7th post-TBI month, rats were video-EEG monitored for epilepsy diagnosis.

RESULTS

A total of 245 rats were video-EEG phenotyped for epilepsy on the 7th postinjury month (121 in MRI cohort, 124 in EEG cohort). In the whole cohort (n = 245), the prevalence of PTE in rats with TBI was 22%, being 27% in the MRI and 18% in the EEG cohort (p > .05). Prevalence of PTE did not differ between the three study sites (p > .05). The average seizure frequency was .317 ± .725 seizures/day at University of Eastern Finland (UEF; Finland), .085 ± .067 at Monash University (Monash; Australia), and .299 ± .266 at University of California, Los Angeles (UCLA; USA; p < .01 as compared to Monash). The average seizure duration did not differ between UEF (104 ± 48 s), Monash (90 ± 33 s), and UCLA (105 ± 473 s; p > .05). Of the 219 seizures, 53% occurred as part of a seizure cluster (≥3 seizures/24 h; p >.05 between the study sites). Of the 209 seizures, 56% occurred during lights-on period and 44% during lights-off period (p > .05 between the study sites).

SIGNIFICANCE

The PTE phenotype induced by lateral FPI is reproducible in a multicenter design. Our study supports the feasibility of performing preclinical multicenter trials in PTE to increase statistical power and experimental rigor to produce clinically translatable data to combat epileptogenesis after TBI.

Neuropsychological Impairments in Patients With Post-traumatic Epilepsy: A Scoping Review

OBJECTIVES

To date, the research on the prognosis of the neuropsychological function of patients with post-traumatic seizure (PTE) is sparse. This study aimed to systematically map the literature's extent, range, and characteristics regarding PTE and neuropsychological impairments.

METHODS

A systematic literature search was conducted in CINAHL, Cochrane, Embase, Medline, PubMed, Scopus, Web of Science, and ScienceDirect databases. The search terms were related to PTE and neuropsychological impairments.

RESULTS

This scoping review included seven studies, two of which examined the impact of PTE on neuropsychological outcomes. Among the three studies that used neuropsychological assessments, attention/concentration, and memory were the most frequently assessed domains. Only one study reported a significant difference between PTE and non-PTE patients. The cognitive rating scale findings in the other four studies were similar, indicating that patients with PTE performed worse than those without PTE.

CONCLUSIONS

The results of this review suggest that patients with PTE may have neuropsychological function impairments. More attention needs to be paid to older patients and those with higher brain injury and seizure severity. Additional investigation is necessary to determine the clinical characteristics of TBI and PTE and elucidate the relations between PTE and specific neuropsychological domains.

Risk of Epilepsy Following Traumatic Brain Injury: A Systematic Review and Meta-analysis

BACKGROUND

Limited evidence has explored the impact of traumatic brain injury (TBI) on posttraumatic epilepsy with control cohort for comparison. In addition, we could not find any review to identify the effect of TBI on the outcomes. Thus, we conducted this study to compare the risk of epilepsy between individuals with TBI and without TBI.

METHODS

Systematic and comprehensive search was carried out in the following databases and search engines: EMBASE, Cochrane, MEDLINE, ScienceDirect, and Google Scholar from 1954 until January 2022. The Newcastle Ottawa (NO) Scale was utilized to assess the risk of bias. Meta-analysis was carried out using the random-effects model, and pooled odds ratio (OR) along with 95% CI was reported.

RESULTS

In total, we included 10 studies satisfying inclusion criteria. Most studies had good to satisfactory quality. The pooled OR was 4.25 (95% CI, 1.77-10.25; I2 = 100%), indicating that the individuals with TBI had 4.25 times higher risk of having epilepsy than individuals without TBI, and this association was statistically significant ( P = .001). Subgroup analysis based on the years of follow-up revealed that the patients within 5 years post-TBI had the highest risk of epilepsy (pooled OR = 7.27; 95% CI, 3.61-14.64).

CONCLUSION

Individuals with TBI had a significantly higher risk of epilepsy than the individuals without TBI, irrespective of the duration of the injury. Hence, long-term follow-up of the individuals with TBI is necessary to prevent any adverse consequences.

Biomarker S100B in plasma a screening tool for mild traumatic brain injury in an emergency department

INTRODUCTION

A computerized tomography (CT) scan is an effective test for detecting traumatic intracranial findings after mild traumatic brain injury (mTBI). However, a head CT is costly, and can only be performed in a hospital.

OBJECTIVE

To determine if the addition of plasma S100B to clinical guidelines could lead to a more selective scanning strategy without compromising safety.

METHODS

We conducted a single center prospective cohort study at the emergency department. Patients (≥16 years) who received head CT and had a blood draw were included. The primary outcome was the accuracy of plasma S100B to predict the presence of any traumatic intracranial lesion on head CT.

RESULTS

We included 495 patients, out of the 74 patients who had traumatic intracranial lesions, 5 patients had a plasma S100B level below the cutoff value of 0.105 ug/L. For the detection of traumatic intracranial injury, S100B had a sensitivity of 0.932 , a specificity of 0.157, a negative predictive value of 0.930, and a positive predictive value of 0.163.

CONCLUSIONS

Among patients undergoing guideline-based CT scan for mTBI, the use of S100B, would results in a further decrease (14.8%) of CT scans but at a cost of missed injury, without clinical consequence, on CT.

Unplanned Admissions, Emergency Department Visits, and Epilepsy After Critical Neurological Illness Requiring Prolonged Mechanical Ventilation in Children

Background and Purpose

Long-term outcomes after pediatric neurocritical illness are poorly characterized. This study aims to characterize the frequency and risk factors for post-discharge unplanned health resource use in a pediatric neurocritical care population using insurance claims data.

Methods

Retrospective cohort study evaluating children who survived a hospitalization for an acute neurologic illness or injury requiring mechanical ventilation for >72 hours and had insurance eligibility in Colorado's All Payers Claims database. Insurance claims identified unplanned readmissions and emergency department [ED] visits during the post-discharge year. For patients without pre-existing epilepsy/seizures, we evaluated for post-ICU epilepsy identified by claim(s) for a maintenance anti-seizure medication during months 6-12 post-discharge. Multivariable logistic regression identified factors associated with each outcome.

Results

101 children, median age 3.7 years (interquartile range (IQR) .4-11.9), admitted for trauma (57%), hypoxic-ischemic injury (17%) and seizures (15%). During the post-discharge year, 4 (4%) patients died, 26 (26%) were readmitted, and 48 (48%) had an ED visit. Having a pre-existing complex chronic condition was independently associated with readmission and emergency department visit. Admission for trauma was protective against readmission. Of those without pre-existing seizures (n = 86), 25 (29%) developed post-ICU epilepsy. Acute seizures during admission and prolonged ICU stays were independently associated with post-ICU epilepsy.

Conclusions

Survivors of pediatric neurocritical illness are at risk of unplanned healthcare use and post-ICU epilepsy. Critical illness risk factors including prolonged ICU stay and acute seizures may identify cohorts for targeted follow up or interventions to prevent unplanned healthcare use and post-ICU epilepsy.

Predicting Global Functional Outcomes Among Post-traumatic Epilepsy Patients After Moderate-to-Severe Traumatic Brain Injury: Development of a Prognostic Model

Objective

The development of post-traumatic epilepsy (PTE) following traumatic brain injury (TBI) is associated with unfavorable functional outcomes, and the global function of PTE patients might change dynamically overtime. Predicting the long-term functional outcomes of patients with PTE may help to develop accurate rehabilitation programs and improve their quality of life. Based on this, the objective of this study is to use clinical data to derive and validate a model for predicting the functional outcomes of patients with PTE after moderate-to-severe TBI.

Methods

This study retrospectively analyzed 721 patients with PTE after moderate-to-severe TBI in the Epilepsy Centre, Beijing Tiantan Hospital, from January 2013 to December 2018. All patients had favorable global function as indicated by the Glasgow Outcome Scale-Extended (GOSE) at the time of their first late post-traumatic seizure (PTS) onset, and the 5-year global function after the first late PTS onset was chosen as the principal outcome of interest. To identify possible predictors for the global functional outcomes, univariate and multivariate logistic regression techniques were used. A prognostic model was established using these identified predictors, the internal validation with the bootstrapping method was performed, and the model was then visualized as a graphical score chart.

Results

The 5-year global functional outcome of 98 (13.59%) patients was unfavorable, and the temporal lobe lesion was found as the strongest predictor of unfavorable outcomes. The final prognostic model also included the following other predictors: gender, age at TBI, multiple injuries, the severity of TBI, and latency of PTE. Discrimination was satisfactory with C-statistic of 0.754 (0.707 – 0.800), the goodness-of-fit test indicated good calibration (P = 0.137), and the C-statistic was 0.726 for internal validation. A graphical score chart was also constructed to provide the probability of an unfavorable 5-year global functional outcomes more readily.

Conclusions

Clearer treatment strategies are essential to help ameliorate the global functional outcomes of patients with PTE. Our proposed prognostic model has significant potential to be used in the clinic for predicting global functional outcomes among patients with PTE after moderate-to-severe TBI.

Multimodal Quality of Life Assessment in Post-9/11 Veterans With Epilepsy: Impact of Drug Resistance, Traumatic Brain Injury, and Comorbidity

BACKGROUND AND OBJECTIVES

Epilepsy is defined by the occurrence of multiple unprovoked seizures, but quality of life (QOL) in people with epilepsy is determined by multiple factors, in which psychiatric comorbidities play a pivotal role. Therefore, understanding the interplay between comorbidities and QOL across epilepsy phenotypes is an important step towards improved outcomes. Here, we report the impact of QOL across distinct epilepsy phenotypes in a cohort of post-9/11 veterans with high rates of traumatic brain injury (TBI).

METHODS

This observational cohort study from the Veterans Health Administration included post-9/11 Veterans with epilepsy. A process integrating an epilepsy identification algorithm, chart abstraction, and self-reported measures was used to classify patients into one of four groups: 1. Epilepsy controlled with medications, 2. Drug resistant epilepsy (DRE), 3. Post-traumatic epilepsy (PTE), or 4. Drug resistant post-traumatic epilepsy (PT-DRE). Summary scores for six QOL measures were compared across the groups, adjusting for age, sex, and number of comorbidities.

RESULTS

A total of 529 survey respondents with epilepsy were included in the analysis: 249 controls (i.e., epilepsy without DRE or PTE), 124 with DRE, 86 with PTE, and 70 with PT-DRE. Drug resistant epilepsy was more common in those with PTE compared with non-traumatic epilepsy (45% vs. 33%, odds ratio 1.6 (95% CI: [1.1-2.4], p=0.01)). Patients with PTE and PT-DRE had significantly more comorbid conditions in health records than those with nontraumatic epilepsy. Those with both PTE and DRE reported the lowest QOL across all six measures, and this persisted after adjustment for comorbidities, and in further linear analyses.

DISCUSSION

Among those with PTE, DRE prevalence was significantly higher than for non-traumatic epilepsies. PTE was also associated with higher burden of comorbidity, and worse overall QOL compared to those with non-traumatic epilepsies. People with PTE are distinctly vulnerable to the comorbidities associated with TBI and epilepsy. This at-risk group should be the focus of future studies aimed at elucidating the factors associated with adverse health outcomes and developing anti-epileptogenic therapies.

An Interplay Between Post-Traumatic Epilepsy and Associated Cognitive Decline: A Systematic Review

Background

Post-traumatic epilepsy (PTE) is a devastating neurological outcome of traumatic brain injury (TBI), which may negatively impact the quality of life of patients with TBI, and may impose a huge socioeconomic burden. This burden may be due to long-term functional outcomes associated with PTE, particularly cognitive dysfunction. To date, the relationship between TBI and PTE remains unclear, with little known about how the effect of their link on cognitive function as well.

Objective

Thus, this systematic review aimed at elucidating the relationship between PTE and cognitive impairment in adults after TBI based on available clinical studies, in hopes to aid in the development of therapeutic strategies for PTE.

Methods

A systematic literature search was performed using 6 databases; MEDLINE, Embase, CINAHL, Psych INFO, Web of Science, and Cochrane to retrieve relevant clinical studies investigating the link between PTE and cognition in the context of TBI. The Newcastle-Ottawa Scale (NOS) was used to assess the methodological quality of relevant studies.

Results

A total of six eligible studies were included for critical appraisal in this review after performing the inclusion and exclusion criteria, which involved 1,100 individuals, from 1996 to 2021. The selected studies were derived from the civilian and military population, with a follow-up period that ranged from 6 months to 35 years. The average quality of the involved studies was moderate (6.6, SD = 1.89). Five out of six studies found poorer cognitive performance in people with PTE, compared with those without PTE. Although the association between PTE and cognitive impairment was insignificant after controlling for specific covariates, there was a statistical trend toward significance.

Conclusion

This systematic review suggests that there may be a possible link between PTE and cognitive decline in TBI patients, with the latter being reported to occur up to 35 years post injury. Variations in sample sizes, follow-up periods, and neuropsychological assessment tools may be the limitations affecting the interpretation and significance of this relationship. Therefore, future studies with standard cognitive assessment tools may be warranted to solidify the link between TBI-PTE-cognitive dysfunction, prior to the development of therapeutic strategies.

Systematic Review Registration:https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42020221702, prospero identifier: CRD42020221702.

Association of Posttraumatic Epilepsy With 1-Year Outcomes After Traumatic Brain Injury

IMPORTANCE

Posttraumatic epilepsy (PTE) is a recognized sequela of traumatic brain injury (TBI), but the long-term outcomes associated with PTE independent of injury severity are not precisely known.

OBJECTIVE

To determine the incidence, risk factors, and association with functional outcomes and self-reported somatic, cognitive, and psychological concerns of self-reported PTE in a large, prospectively collected TBI cohort.

DESIGN, SETTING, AND PARTICIPANTS

This multicenter, prospective cohort study was conducted as part of the Transforming Research and Clinical Knowledge in Traumatic Brain Injury study and identified patients presenting with TBI to 1 of 18 participating level 1 US trauma centers from February 2014 to July 2018. Patients with TBI, extracranial orthopedic injuries (orthopedic controls), and individuals without reported injuries (eg, friends and family of participants; hereafter friend controls) were prospectively followed for 12 months. Data were analyzed from January 2020 to April 2021.

EXPOSURE

Demographic, imaging, and clinical information was collected according to TBI Common Data Elements. Incidence of self-reported PTE was assessed using the National Institute of Neurological Disorders and Stroke Epilepsy Screening Questionnaire (NINDS-ESQ).

MAIN OUTCOMES AND MEASURES

Primary outcomes included Glasgow Outcome Scale Extended, Rivermead Cognitive Metric (RCM; derived from the Rivermead Post Concussion Symptoms Questionnaire), and the Brief Symptom Inventory-18 (BSI).

RESULTS

Of 3296 participants identified as part of the study, 3044 met inclusion criteria, and 1885 participants (mean [SD] age, 41.3 [17.1] years; 1241 [65.8%] men and 644 [34.2%] women) had follow-up information at 12 months, including 1493 patients with TBI; 182 orthopedic controls, 210 uninjured friend controls; 41 patients with TBI (2.8%) and no controls had positive screening results for PTE. Compared with a negative screening result for PTE, having a positive screening result for PTE was associated with presenting Glasgow Coma Scale score (8.1 [4.8] vs.13.5 [3.3]; P < .001) as well as with anomalous acute head imaging findings (risk ratio, 6.42 [95% CI, 2.71-15.22]). After controlling for age, initial Glasgow Coma Scale score, and imaging findings, compared with patients with TBI and without PTE, patients with TBI and with positive PTE screening results had significantly lower Glasgow Outcome Scale Extended scores (mean [SD], 6.1 [1.7] vs 4.7 [1.5]; P < .001), higher BSI scores (mean [SD], 50.2 [10.7] vs 58.6 [10.8]; P = .02), and higher RCM scores (mean [SD], 3.1 [2.6] vs 5.3 [1.9]; P = .002) at 12 months.

CONCLUSIONS AND RELEVANCE

In this cohort study, the incidence of self-reported PTE after TBI was found to be 2.8% and was independently associated with unfavorable outcomes. These findings highlight the need for effective antiepileptogenic therapies after TBI.

Post-Traumatic Epilepsy in Zebrafish Is Drug-Resistant and Impairs Cognitive Function

Post-traumatic epilepsy (PTE) is acquired epilepsy after traumatic brain injury (TBI). Despite the availability of more than 20 antiseizure medications (ASMs), there is no way at present to prevent epileptogenesis in TBI survivors, and many cases of PTE become drug-resistant. Importantly, the adverse effects of ASMs can significantly affect patients' quality of life. Mammalian models are commonly used for studying refractory PTE, but are expensive and laborious. Zebrafish models have become popular for studying epilepsy, but most focus on larvae, and there have been no reports to date of pharmacological screening in an adult zebrafish model of acquired epilepsy. Valid animal models are critical for understanding PTE and for developing novel therapeutics. The aim of the present study was to characterize the cognitive impairments of a zebrafish model of TBI that leads to the development of PTE. Using combined behavioral and electrophysiological approaches, we also characterized the pharmacological effects of the most commonly used ASMs to manage PTE (valproate, carbamazepine, and phenytoin). Zebrafish with PTE exhibited impairments in learning and memory, difficulty in decision making, and reduced social preference. Valproate and carbamazepine had a limited protective effect against behavioral seizures, and all three drugs failed to significantly reduce electrographical seizures. The negative impacts of TBI and ASMs in zebrafish parallel those observed in other animals, making the zebrafish model of PTE a promising high-throughput model of refractory and drug-resistant epilepsy.

The Military Injuries: Understanding Post-Traumatic Epilepsy Study: Understanding Relationships among Lifetime Traumatic Brain Injury History, Epilepsy, and Quality of Life

Understanding risk for epilepsy among persons who sustain a mild (mTBI) traumatic brain injury (TBI) is crucial for effective intervention and prevention. However, mTBI is frequently undocumented or poorly documented in health records. Further, health records are non-continuous, such as when persons move through health systems (e.g., from Department of Defense to Veterans Affairs [VA] or between jobs in the civilian sector), making population-based assessments of this relationship challenging. Here, we introduce the MINUTE (Military INjuries-Understanding post-Traumatic Epilepsy) study, which integrates data from the Veterans Health Administration with self-report survey data for post-9/11 veterans (n = 2603) with histories of TBI, epilepsy and controls without a history of TBI or epilepsy. This article describes the MINUTE study design, implementation, hypotheses, and initial results across four groups of interest for neurotrauma: 1) control; 2) epilepsy; 3) TBI; and 4) post-traumatic epilepsy (PTE). Using combined survey and health record data, we test hypotheses examining lifetime history of TBI and the differential impacts of TBI, epilepsy, and PTE on quality of life. The MINUTE study revealed high rates of undocumented lifetime TBIs among veterans with epilepsy who had no evidence of TBI in VA medical records. Further, worse physical functioning and health-related quality of life were found for persons with epilepsy + TBI compared to those with either epilepsy or TBI alone. This effect was not fully explained by TBI severity. These insights provide valuable opportunities to optimize the resilience, delivery of health services, and community reintegration of veterans with TBI and complex comorbidity.

Traumatic Brain Injury and Treatment of Behavioral Health Conditions

Traumatic brain injury (TBI) is a common neurological condition that results from an external force altering normal brain function, whether temporarily or permanently. A concussion is one type of TBI. TBIs vary greatly in severity, which concomitantly creates tremendous variability in their manifestation. The fingerprint of TBI is damage to the frontal areas of the brain, which, with sufficient magnitude, results in impairment of a person's ability to regulate cognition, emotion, and behavior. These consequences of TBI make recognition in the context of treating behavioral health conditions of utmost importance. TBI not only causes behavioral health problems but also produces associated deficits that can undermine the effectiveness of treatment for a behavioral health condition. This overview delineates key characteristics of TBI and describes its association with behavioral health conditions. Mechanisms underlying the relationship between TBI and behavioral health are presented, and a series of recommendations for professionals are proposed. This article is intended to raise awareness about TBI and simultaneously introduce key concepts for accommodating the effects of TBI in behavioral health care.

Seizure and status epilepticus in chronic subdural hematoma

BACKGROUND

Acute symptomatic seizure (ASz) and status epilepticus (SE) are serious conditions associated with poor quality of life, with unfavorable psychosocial and functional outcome. Chronic subdural hematoma (cSDH) is a common neurosurgical disease related to those complications; therefore, we aimed to evaluate incidence, predictors of ASz/SE, and outcome in this cohort.

METHODS

We retrospectively analyzed patient diagnosed cSDH between 2010 and 2017. Beside their incidence of ASz/SE, patient characteristics, symptoms at admission, comorbidities, and all previously published relevant parameters were assessed. Recurrence rate and functional outcome were analyzed at hospital discharge and 90-day follow-up.

RESULTS

A total of 375 patients were included; incidence of ASz was 15.2% and of SE, 1.9%. In the univariate analysis, drainage insertion (P =  0.004; OR = 0.3) was a significant negative predictor for ASz/SE and multivariate analysis, including all significant parameters, designated GCS ≤13 at admission (P = 0.09; OR = 1.9), remote stroke (P = 0.009; OR = 2.9), and recurrence rate within 14 days (P = 0.001; OR = 3.3; with an incidence of 13%) as independent predictors for ASz/SE. Overall, patients with ASz/SE had significantly unfavorable outcome at discharge (54.7%; P < 0.001) and follow-up (39.5%; P < 0.001) with only slight improvement. Late seizures occurred in 3.8% within follow-up period. Any patient with SE had an unfavorable outcome at discharge without any improvement at follow-up having a mortality rate of 14.2%.

CONCLUSION

Independent predictors for ASz/SE are GCS ≤13 at admission, remote stroke, and recurrent hematoma in patients with cSDH, which is associated with worse functional outcome, particularly those with SE. Due to the higher rate of seizures than recurrence rate, a routine pre- and postoperative EEG besides CT is recommended.

The Transition Trajectory for the Patient with a Traumatic Brain Injury

The trajectory status of patients with mild, moderate, and severe traumatic brain injury from emergency room evaluation, through acute care (intensive care if severe) and discharge is discussed. Additional considerations for elderly population and common complications associated with severe traumatic brain injury are also covered.

Affective, neurocognitive and psychosocial disorders associated with traumatic brain injury and post-traumatic epilepsy

Survivors of traumatic brain injury (TBI) often develop chronic neurological, neurocognitive, psychological, and psychosocial deficits that can have a profound impact on an individual's wellbeing and quality of life. TBI is also a common cause of acquired epilepsy, which is itself associated with significant behavioral morbidity. This review considers the clinical and preclinical evidence that post-traumatic epilepsy (PTE) acts as a 'second-hit' insult to worsen chronic behavioral outcomes for brain-injured patients, across the domains of emotional, cognitive, and psychosocial functioning. Surprisingly, few well-designed studies have specifically examined the relationship between seizures and behavioral outcomes after TBI. The complex mechanisms underlying these comorbidities remain incompletely understood, although many of the biological processes that precipitate seizure occurrence and epileptogenesis may also contribute to the development of chronic behavioral deficits. Further, the relationship between PTE and behavioral dysfunction is increasingly recognized to be a bidirectional one, whereby premorbid conditions are a risk factor for PTE. Clinical studies in this arena are often challenged by the confounding effects of anti-seizure medications, while preclinical studies have rarely examined an adequately extended time course to fully capture the time course of epilepsy development after a TBI. To drive the field forward towards improved treatment strategies, it is imperative that both seizures and neurobehavioral outcomes are assessed in parallel after TBI, both in patient populations and preclinical models.

Craniectomy and Craniotomy in Traumatic Brain Injury: A Propensity-Matched Analysis of Long-Term Functional and Quality of Life Outcomes

OBJECTIVE

To report the comprehensive long-term functional and quality of life outcomes after craniectomy (CE) and craniotomy (CO) in individuals with traumatic brain injury (TBI).

METHODS

Information on all individuals with TBI who had undergone CE or CO were extracted from the TBI Model Systems database from 2002 to 2012. A 1:1 propensity matching with replacement technique was used to balance the baseline characteristics across groups. The matched sample was analyzed for outcomes during hospitalization, acute rehabilitation, and ≤2 years of follow-up.

RESULTS

We identified 1470 individuals who had undergone CE or CO. Individuals undergoing CE compared with CO demonstrated a longer length of stay in the hospital (median, 22 vs. 18 days; P < 0.0001) and acute rehabilitation (median 26 vs. 21 days; P < 0.0001). Individuals with CE had required rehospitalization more often by the 1-year follow-up point (39% vs. 25%; P < 0.0001) for reasons other than cranioplasty, including seizures (12% vs. 8%; P < 0.0001), neurologic events (i.e., hydrocephalus; 9% vs. 4%; P < 0.0001), and infections (10% vs 6%; P < 0.0001). Individuals with CE had significantly greater impairment using the Glasgow Outcome Scale-Extended, required more supervision, and were less likely to be employed at 1 and 2 years after TBI. No difference was observed in the satisfaction with life scale scores at 2 years. The Kaplan-Meier mortality estimates at 1 and 2 years showed no differences between the 2 groups (hazard ratio, 0.57; P = 0.4).

CONCLUSION

In a matched cohort, individuals undergoing CE compared with CO after TBI had a longer length of stay, decreased functional status, and more rehospitalizations. The survival at 2 years and the satisfaction with life scale scores were similar.

Seizure Prophylaxis Guidelines Following Traumatic Brain Injury: An Evaluation of Compliance

OBJECTIVE

To determine degree of adherence to guidelines for seizure prophylaxis following traumatic brain injury (TBI).

SETTING

Tertiary care level 1 trauma center and affiliated inpatient rehabilitation facility.

PARTICIPANTS

A total of 173 individuals with TBI who required inpatient rehabilitation from January 1, 2007, to December 31, 2013.

DESIGN

Retrospective medical record review.

MAIN MEASURES

Overutilization rate of prophylactic antiepileptic drugs (AEDs); failure to stop rate of AED utilization upon admission to and during inpatient rehabilitation; and duration of overutilization.

RESULTS

Of the 173 participants included, 77 were started on seizure prophylaxis at hospital presentation and 96 were not. Of the 77 participants, 11 had a posttraumatic seizure. Of the 66 remaining, 18 participants (10.4%) were continued on AEDs for more than 7 days after injury. Of these 18 participants, 12 were continued on AEDs without indication upon admission to inpatient rehabilitation. Finally, 8 of the 12 were continued on AEDs at discharge from rehabilitation, resulting in a failure to stop rate of 66.67%.

CONCLUSION

Despite existing guidelines for stopping seizure prophylaxis after TBI, some patients remain on AEDs and may be inappropriately exposed to possible medication side effects. These findings highlight the importance of communication at the time of rehabilitation transfer and the need for ongoing education about AED guidelines.

Derivation of a Three Biomarker Panel to Improve Diagnosis in Patients with Mild Traumatic Brain Injury

Background

Nearly 5 million emergency department (ED) visits for head injury occur each year in the United States, of which <10% of patients show abnormal computed tomography (CT) findings. CT negative patients frequently suffer protracted somatic, behavioral, and neurocognitive dysfunction. Our goal was to evaluate biomarkers to identify mild TBI (mTBI) in patients with suspected head injury.

Methods

An observational ED study of head-injured and control patients was conducted at Johns Hopkins University (HeadSMART). Head CT was obtained (ACEP criteria) in patients with Glasgow Coma Scale scores of 13–15 and aged 18–80. Three candidate biomarker proteins, neurogranin (NRGN), neuron-specific enolase (NSE), and metallothionein 3 (MT3), were evaluated by immunoassay (samples <24 h from injury). American Congress of Rehabilitation Medicine (ACRM) criteria were used for diagnosis of mTBI patients for model building. Univariate analysis, logistic regression, and random forest (RF) algorithms were used for data analysis in R. Overall, 662 patients were studied. Statistical models were built using 328 healthy controls and 179 mTBI patients.

Results

Median time from injury was 5.9 h (IQR, 4.0; range 0.8–24 h). mTBI patients had elevated NSE, but decreased MT3 versus controls (p < 0.01 for each). NRGN was also elevated but within 2–6 h after injury. In the derivation set, the best model to distinguish mTBI from healthy controls used three markers, age, and sex as covariates (C-statistic = 0.91, sensitivity 98%, specificity 72%). Panel test accuracy was validated with the 155 remaining ACRM+ mTBI patients. Applying the RF model to the ACRM+ mTBI validation set resulted in 78% correctly classified as mTBI (119/153). CT positive and CT negative validation subsets were 91% and 75% correctly classified. In samples taken <2 h from injury, 100% (10/10) samples classified correctly, indicating that hyperacute testing is possible with these biomarker assays. The model accuracy varied from 72–100% overall, and had greater accuracy with increasing severity, as shown by comparing CT+ with CT− (91% versus 75%), and Injury Severity Score ≥16 versus <16 (88% versus 72%, respectively). Objective blood tests, detecting NRGN, NSE, and MT3, can be used to identify mTBI, irrespective of neuroimaging findings.

Post-traumatic epilepsy associations with mental health outcomes in the first two years after moderate to severe TBI: A TBI Model Systems analysis

PURPOSE

Research suggests that there are reciprocal relationships between mental health (MH) disorders and epilepsy risk. However, MH relationships to post-traumatic epilepsy (PTE) have not been explored. Thus, the objective of this study was to assess associations between PTE and frequency of depression and/or anxiety in a cohort of individuals with moderate-to-severe TBI who received acute inpatient rehabilitation.

METHODS

Multivariate regression models were developed using a recent (2010-2012) cohort (n=867 unique participants) from the TBI Model Systems (TBIMS) National Database, a time frame during which self-reported seizures, depression [Patient Health Questionnaire (PHQ)-9], and anxiety [Generalized Anxiety Disorder (GAD-7)] follow-up measures were concurrently collected at year-1 and year-2 after injury.

RESULTS

PTE did not significantly contribute to depression status in either the year-1 or year-2 cohort, nor did it contribute significantly to anxiety status in the year-1 cohort, after controlling for other known depression and anxiety predictors. However, those with PTE in year-2 had 3.34 times the odds (p=.002) of having clinically significant anxiety, even after accounting for other relevant predictors. In this model, participants who self-identified as Black were also more likely to report clinical symptoms of anxiety than those who identified as White. PTE was the only significant predictor of comorbid depression and anxiety at year-2 (Odds Ratio 2.71; p=0.049).

CONCLUSIONS

Our data suggest that PTE is associated with MH outcomes 2years after TBI, findings whose significance may reflect reciprocal, biological, psychological, and/or experiential factors contributing to and resulting from both PTE and MH status post-TBI. Future work should consider temporal and reciprocal relationships between PTE and MH as well as if/how treatment of each condition influences biosusceptibility to the other condition.

Unintentional injuries after TBI: Potential risk factors, impacts, and prevention

BACKGROUND

The top three causes of fatal unintentional injuries are falls, motor vehicle crashes, and being struck against or struck by objects or persons. These etiologies also happen to be the leading causes of TBI, a serious public health problem, in the US. Reduced cognitive functioning, poor decision making, increased risk taking, disinhibition, diminished safety skills and substance use, place individuals with TBI at an increased risk for subsequent unintentional injuries. The caregiving, psychological, social and financial burden of initial injuries is enormous. Unintentional injuries post-TBI add to that burden significantly. Many unintentional injuries can be prevented with simple education and environment and lifestyle changes. Injury prevention requires collaboration among many.

OBJECTIVE

This literature review will share information regarding potential triggers or causes of unintentional injuries after TBI to identify potential issues. The many impacts of these injuries will be reviewed. Best practices in prevention will be presented.

CONCLUSION

Ultimately, education, discussion, and awareness across multiple stakeholders can aid in preventing unintentional injuries after TBI.

Management of post-traumatic epilepsy: An evidence review over the last 5 years and future directions

Post‐traumatic epilepsy (PTE) is a relatively underappreciated condition that can develop as a secondary consequence following traumatic brain injury (TBI). The aim of this rapid evidence review is to provide a synthesis of existing evidence on the effectiveness of treatment interventions for the prevention of PTE in people who have suffered a moderate/severe TBI to increase awareness and understanding among consumers. Electronic medical databases (n = 5) and gray literature published between January 2010 and April 2015 were searched for studies on the management of PTE. Twenty‐two eligible studies were identified that met the inclusion criteria. No evidence was found for the effectiveness of any pharmacological treatments in the prevention or treatment of symptomatic seizures in adults with PTE. However, limited high‐level evidence for the effectiveness of the antiepileptic drug levetiracetam was identified for PTE in children. Low‐level evidence was identified for nonpharmacological interventions in significantly reducing seizures in patients with PTE, but only in a minority of cases, requiring further high‐level studies to confirm the results. This review provides an opportunity for researchers and health service professionals to better understand the underlying pathophysiology of PTE to develop novel, more effective therapeutic targets and to improve the quality of life of people with this condition.

Risk factors for posttraumatic epilepsy: A systematic review and meta-analysis

OBJECTIVE

A systematic review and meta-analysis was performed to identify risk factors for posttraumatic epilepsy (PTE).

METHODS

Two electronic databases (Medline and Embase) were searched to identify studies with a cohort, case-control, or cross-sectional design reporting on epidemiologic evidence regarding risk factors for PTE.

RESULTS

Men had a higher risk of developing PTE than women [relative ratio (RR), 1.32; 95% confidence interval (CI), 1.10-1.59]. A history of alcohol abuse (RR, 2.18; 95% CI, 1.26-3.79), posttraumatic amnesia (RR, 1.31; 95% CI, 1.12-1.53), focal neurologic signs (RR, 1.42; 95% CI, 1.16-1.74), and loss of consciousness at initial traumatic brain injury (TBI) (RR, 1.62; 95% CI, 1.13-2.32) were associated with a greater risk of PTE. TBI-related abnormal neuroimaging findings, including skull fracture (RR, 2.27; 95% CI, 1.49-3.44), midline shift (RR, 1.46; 95% CI, 1.14-1.87), brain contusion (RR, 2.35; 95% CI, 1.69-3.28), subdural hemorrhage (RR, 2.00; 95% CI, 1.33-3.01), and intracranial hemorrhage (RR, 2.65; 95% CI, 1.83-3.82) were strong risk factors for PTE. The risk of developing PTE after skull fracture, mild brain injury, and severe brain injury peaked within the first year after TBI, and then gradually decreased. However, a high risk of PTE was sustained for >10years.

CONCLUSION

The current meta-analysis identified potential risk factors for PTE. The results may contribute to better prevention strategies and treatments for PTE.

Neuroprotection and anti-seizure effects of levetiracetam in a rat model of penetrating ballistic-like brain injury

PURPOSE

We assessed the therapeutic efficacy of FDA-approved anti-epileptic drug Levetiracetam (LEV) to reduce post-traumatic nonconvulsive seizure (NCS) activity and promote neurobehavioral recovery following 10% frontal penetrating ballistic-like brain injury (PBBI) in male Sprague-Dawley rats.

METHODS

Experiment 1 anti-seizure study: 50 mg/kg LEV (25 mg/kg maintenance doses) was given twice daily for 3 days (LEV3D) following PBBI; outcome measures included seizures incidence, frequency, duration, and onset. Experiment 2 neuroprotection studies: 50 mg/kg LEV was given twice daily for either 3 (LEV3D) or 10 days (LEV10D) post-injury; outcome measures include motor (rotarod) and cognitive (water maze) functions.

RESULTS

LEV3D treatment attenuated seizure activity with significant reductions in NCS incidence (54%), frequency, duration, and delayed latency to seizure onset compared to vehicle treatment. LEV3D treatment failed to improve cognitive or motor performance; however extending the dosing regimen through 10 days post-injury afforded significant neuroprotective benefit. Animals treated with the extended LEV10D dosing regimen showed a twofold improvement in rotarod task latency to fall as well as significantly improved spatial learning performance (24%) in the MWM task.

CONCLUSIONS

These findings support the dual anti- seizure and neuroprotective role of LEV, but more importantly identify the importance of an extended dosing protocol which was specific to the therapeutic targets studied.

Sense of Community and Its Impact on the Life Satisfaction of Adults With Brain Injury

Sense of community (SOC) refers to feelings of belonging and attachment one has for a community. Despite a growing focus on adjustment and community outcomes following disability, this construct has received little attention in the rehabilitation literature. The primary aim of this study was to examine the extent to which SOC and social identification with one’s town contribute to life satisfaction outcomes among adults with brain injury, controlling for demographic, disability, and other related social constructs (e.g., social support and social integration). Members from brain injury associations across the United States ( N = 177) participated in a survey-based study. Results from hierarchical regression analysis indicated that the final model accounted for 45% of the variance in life satisfaction, with SOC variables contributing 11%. Symptom severity, perceived emotional support, and the SOC dimension reinforcement of needs were significant independent predictors of life satisfaction. Findings from this study highlight the importance of examining SOC variables among clients with brain injury to enhance subjective well-being.

Prognostic models for predicting posttraumatic seizures during acute hospitalization, and at 1 and 2 years following traumatic brain injury

OBJECTIVE

Posttraumatic seizures (PTS) are well-recognized acute and chronic complications of traumatic brain injury (TBI). Risk factors have been identified, but considerable variability in who develops PTS remains. Existing PTS prognostic models are not widely adopted for clinical use and do not reflect current trends in injury, diagnosis, or care. We aimed to develop and internally validate preliminary prognostic regression models to predict PTS during acute care hospitalization, and at year 1 and year 2 postinjury.

METHODS

Prognostic models predicting PTS during acute care hospitalization and year 1 and year 2 post-injury were developed using a recent (2011-2014) cohort from the TBI Model Systems National Database. Potential PTS predictors were selected based on previous literature and biologic plausibility. Bivariable logistic regression identified variables with a p-value < 0.20 that were used to fit initial prognostic models. Multivariable logistic regression modeling with backward-stepwise elimination was used to determine reduced prognostic models and to internally validate using 1,000 bootstrap samples. Fit statistics were calculated, correcting for overfitting (optimism).

RESULTS

The prognostic models identified sex, craniotomy, contusion load, and pre-injury limitation in learning/remembering/concentrating as significant PTS predictors during acute hospitalization. Significant predictors of PTS at year 1 were subdural hematoma (SDH), contusion load, craniotomy, craniectomy, seizure during acute hospitalization, duration of posttraumatic amnesia, preinjury mental health treatment/psychiatric hospitalization, and preinjury incarceration. Year 2 significant predictors were similar to those of year 1: SDH, intraparenchymal fragment, craniotomy, craniectomy, seizure during acute hospitalization, and preinjury incarceration. Corrected concordance (C) statistics were 0.599, 0.747, and 0.716 for acute hospitalization, year 1, and year 2 models, respectively.

SIGNIFICANCE

The prognostic model for PTS during acute hospitalization did not discriminate well. Year 1 and year 2 models showed fair to good predictive validity for PTS. Cranial surgery, although medically necessary, requires ongoing research regarding potential benefits of increased monitoring for signs of epileptogenesis, PTS prophylaxis, and/or rehabilitation/social support. Future studies should externally validate models and determine clinical utility.

Interrelation between Neuroendocrine Disturbances and Medical Complications Encountered during Rehabilitation after TBI

Traumatic brain injury is not a discrete event but an unfolding sequence of damage to the central nervous system. Not only the acute phase but also the subacute and chronic period after injury, i.e., during inpatient rehabilitation, is characterized by multiple neurotransmitter alterations, cellular dysfunction, and medical complications causing additional secondary injury. Neuroendocrine disturbances also influence neurological outcome and are easily overlooked as they often present with diffuse symptoms such as fatigue, depression, poor concentration, or a decline in overall cognitive function; these are also typical sequelae of traumatic brain injury. Furthermore, neurological complications such as hydrocephalus, epilepsy, fatigue, disorders of consciousness, paroxysmal sympathetic hyperactivity, or psychiatric-behavioural symptoms may mask and/or complicate the diagnosis of neuroendocrine disturbances, delay appropriate treatment and impede neurorehabilitation. The present review seeks to examine the interrelation between neuroendocrine disturbances with neurological complications frequently encountered after moderate to severe TBI during rehabilitation. Common neuroendocrine disturbances and medical complications and their clinical implications are discussed.

Long-Term Consequences of Traumatic Brain Injury: Current Status of Potential Mechanisms of Injury and Neurological Outcomes

Traumatic brain injury (TBI) is a significant clinical problem with few therapeutic interventions successfully translated to the clinic. Increased importance on the progressive, long-term consequences of TBI have been emphasized, both in the experimental and clinical literature. Thus, there is a need for a better understanding of the chronic consequences of TBI, with the ultimate goal of developing novel therapeutic interventions to treat the devastating consequences of brain injury. In models of mild, moderate, and severe TBI, histopathological and behavioral studies have emphasized the progressive nature of the initial traumatic insult and the involvement of multiple pathophysiological mechanisms, including sustained injury cascades leading to prolonged motor and cognitive deficits. Recently, the increased incidence in age-dependent neurodegenerative diseases in this patient population has also been emphasized. Pathomechanisms felt to be active in the acute and long-term consequences of TBI include excitotoxicity, apoptosis, inflammatory events, seizures, demyelination, white matter pathology, as well as decreased neurogenesis. The current article will review many of these pathophysiological mechanisms that may be important targets for limiting the chronic consequences of TBI.

Post-traumatic epilepsy: current and emerging treatment options

Traumatic brain injury (TBI) leads to many undesired problems and complications, including immediate and long-term seizures/epilepsy, changes in mood, behavioral, and personality problems, cognitive and motor deficits, movement disorders, and sleep problems. Clinicians involved in the treatment of patients with acute TBI need to be aware of a number of issues, including the incidence and prevalence of early seizures and post-traumatic epilepsy (PTE), comorbidities associated with seizures and anticonvulsant therapies, and factors that can contribute to their emergence. While strong scientific evidence for early seizure prevention in TBI is available for phenytoin (PHT), other antiepileptic medications, eg, levetiracetam (LEV), are also being utilized in clinical settings. The use of PHT has its drawbacks, including cognitive side effects and effects on function recovery. Rates of recovery after TBI are expected to plateau after a certain period of time. Nevertheless, some patients continue to improve while others deteriorate without any clear contributing factors. Thus, one must ask, 'Are there any actions that can be taken to decrease the chance of post-traumatic seizures and epilepsy while minimizing potential short- and long-term effects of anticonvulsants?' While the answer is 'probably,' more evidence is needed to replace PHT with LEV on a permanent basis. Some have proposed studies to address this issue, while others look toward different options, including other anticonvulsants (eg, perampanel or other AMPA antagonists), or less established treatments (eg, ketamine). In this review, we focus on a comparison of the use of PHT versus LEV in the acute TBI setting and summarize the clinical aspects of seizure prevention in humans with appropriate, but general, references to the animal literature.

Neurobehavioral effects of levetiracetam in patients with traumatic brain injury

Moderate to severe traumatic brain injury (TBI) is one of the leading causes of acquired epilepsy. Prophylaxis for seizures is the standard of care for individuals with moderate to severe injuries at risk for developing seizures, though relatively limited comparative data is available to guide clinicians in their choice of agents. There have however been experimental studies which demonstrate potential neuroprotective qualities of levetiracetam after TBI, and in turn there is hope that eventually such agents may improve neurobehavioral outcomes post-TBI. This mini-review summarizes the available studies and suggests areas for future studies.

Electroencephalographic inverse localization of brain activity in acute traumatic brain injury as a guide to surgery, monitoring and treatment

OBJECTIVE

To inverse-localize epileptiform cortical electrical activity recorded from severe traumatic brain injury (TBI) patients using electroencephalography (EEG).

METHODS

Three acute TBI cases were imaged using computed tomography (CT) and multimodal magnetic resonance imaging (MRI). Semi-automatic segmentation was performed to partition the complete TBI head into 25 distinct tissue types, including 6 tissue types accounting for pathology. Segmentations were employed to generate a finite element method model of the head, and EEG activity generators were modeled as dipolar currents distributed over the cortical surface.

RESULTS

We demonstrate anatomically faithful localization of EEG generators responsible for epileptiform discharges in severe TBI. By accounting for injury-related tissue conductivity changes, our work offers the most realistic implementation currently available for the inverse estimation of cortical activity in TBI.

CONCLUSION

Whereas standard localization techniques are available for electrical activity mapping in uninjured brains, they are rarely applied to acute TBI. Modern models of TBI-induced pathology can inform the localization of epileptogenic foci, improve surgical efficacy, contribute to the improvement of critical care monitoring and provide guidance for patient-tailored treatment. With approaches such as this, neurosurgeons and neurologists can study brain activity in acute TBI and obtain insights regarding injury effects upon brain metabolism and clinical outcome.