Epidemiology of posttraumatic epilepsy: a critical review

Approach to Patients with Seizures and Epilepsy: A Guide for Primary Care Physicians

Seizures and epilepsy are common neurologic conditions that are frequently encountered in the outpatient primary care setting. An accurate diagnosis relies on a thorough clinical history and evaluation. Understanding seizure semiology and classification is crucial in conducting the initial assessment. Knowledge of common seizure triggers and provoking factors can further guide diagnostic testing and initial management. The pharmacodynamic characteristics and side effect profiles of anti-seizure medications are important considerations when deciding treatment and counseling patients, particularly those with comorbidities and in special populations such as patient of childbearing potential.

A role of dentate gyrus mechanistic target of rapamycin activation in epileptogenesis in a mouse model of posttraumatic epilepsy

OBJECTIVE

The mechanistic target of rapamycin (mTOR) pathway has been implicated in promoting epileptogenesis in animal models of acquired epilepsy, such as posttraumatic epilepsy (PTE) following traumatic brain injury (TBI). However, the specific anatomical regions and neuronal populations mediating mTOR's role in epileptogenesis are not well defined. In this study, we tested the hypothesis that mTOR activation in dentate gyrus granule cells promotes neuronal death, mossy fiber sprouting, and PTE in the controlled cortical impact (CCI) model of TBI.

METHODS

An adeno-associated virus (AAV)-Cre viral vector was injected into the hippocampus of Rptorflox/flox (regulatory-associated protein of mTOR) mutant mice to inhibit mTOR activation in dentate gyrus granule cells. Four weeks after AAV-Cre or AAV-vehicle injection, mice underwent CCI injury and were subsequently assessed for mTOR pathway activation by Western blotting, neuronal death, and mossy fiber sprouting by immunopathological analysis, and posttraumatic seizures by video-electroencephalographic monitoring.

RESULTS

AAV-Cre injection primarily affected the dentate gyrus and inhibited hippocampal mTOR activation following CCI injury. AAV-Cre-injected mice had reduced neuronal death in dentate gyrus detected by Fluoro-Jade B staining and decreased mossy fiber sprouting by ZnT3 immunostaining. Finally, AAV-Cre-injected mice exhibited a decrease in incidence of PTE.

SIGNIFICANCE

mTOR pathway activation in dentate gyrus granule cells may at least partly mediate pathological abnormalities and epileptogenesis in models of TBI and PTE. Targeted modulation of mTOR activity in this hippocampal network may represent a focused therapeutic approach for antiepileptogenesis and prevention of PTE.

Effectiveness of Levetiracetam versus phenytoin in preventing seizure in traumatic brain injury patients: A systematic review and meta-analysis

OBJECTIVE

Traumatic brain injury (TBI) and the subsequent Post-traumatic seizure (PTS) is a growing public health concern. Generally, anti-seizure drugs (ASDs) are recommended for PTS prophylaxis and treatment. This meta-analysis aimed to review the current state of knowledge and the evidence for the efficacy and safety of Levetiracetam (LEV) on the incidence of seizure in TBI patients compared to Phenytoin (PHT).

METHODS

A search was carried out based on PubMed, MEDLINE, Europe PMC database, and Cochrane Library up to November 2023. A total of 16 studies (3 randomized clinical trials, 10 retrospective cohort studies, and 3 prospective cohort studies) including 5821 TBI patients included in our meta-analysis. We included studies comparing LEV and PHT after brain injury in both adults and children. Risk of bias assessment was done for randomized controlled trials (RCTs) with a risk-of-bias tool (RoB-2) and the Newcastle-Ottawa Scale (NOS) was used to assess the quality of cohort studies. Two RCTs in our meta-analysis had a high risk of bias, therefore we applied sensitivity analysis to evaluate the robustness of our results.

RESULTS

The most commonly reported dosage for LEV was 500 mg twice daily and for PHT it was 5 mg/kg. There was no significant difference between LEV and PHT groups in reducing the early seizure incidence (OR = 0.85; 95% CI = [0.60, 1.21]; p = 0.375, fixed-effect, I2 = 21.75%). The result of sensitivity analysis for late seizure showed no significant difference between LEV and PHT in reducing the late seizure occurrence after TBI (OR = 0.87; 95% CI = [0.21, 3.67]; p = 0.853, fixed-effect, I2 = 0%). The mortality in TBI patients treated with LEV was not statistically significant compared to the PHT group (OR = 1.11; 95% CI = [0.92, 1.34], p = 0.266). The length of stay in the hospital was not significantly different between the LEV and PHT groups (MD = -1.33; 95% CI = [-4.55, 1.90]; p = 0.421). However, in comparison to PHT, LEV shortened the length of ICU stay (MD = -2.25; 95% CI = [-3.58, -0.91]; p =0.001). In terms of adverse effects, more patients in the PHT group have experienced adverse events compared to LEV but the difference was not significant (OR = 0.69; 95% CI = [0.44, 1.08]; p = 0. 11).

CONCLUSION

The results of our meta-analysis showed LEV and PHT have similar effects on the occurrence of early and late seizures in TBI patients. Therefore, none of the drugs is superior to the other in reducing PTS. However, treating TBI patients with LEV did not shorten the length of hospital stay in comparison to PHT but reduced the length of ICU stay significantly. The analysis showed that patients in the LEV experienced fewer side effects than in the PHT group, while it was not sufficiently clear whether all reported side effects were related to the drug alone or other factors. The mortality was similar between the LEV and PHT groups. Finally, we recommend more high-quality randomized controlled trials to confirm the current findings before making any recommendations in practice.

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.

Transcriptomic alterations in cortical astrocytes following the development of post-traumatic epilepsy

Post-traumatic epilepsy (PTE) stands as one of the numerous debilitating consequences that follow traumatic brain injury (TBI). Despite its impact on many individuals, the current landscape offers only a limited array of reliable treatment options, and our understanding of the underlying mechanisms and susceptibility factors remains incomplete. Among the potential contributors to epileptogenesis, astrocytes, a type of glial cell, have garnered substantial attention as they are believed to promote hyperexcitability and the development of seizures in the brain following TBI. The current study evaluated the transcriptomic changes in cortical astrocytes derived from animals that developed seizures as a result of severe focal TBI. Using RNA-Seq and ingenuity pathway analysis (IPA), we unveil a distinct gene expression profile in astrocytes, including alterations in genes supporting inflammation, early response modifiers, and neuropeptide-amidating enzymes. The findings underscore the complex molecular dynamics in astrocytes during PTE development, offering insights into therapeutic targets and avenues for further exploration.

Clinical Management in Traumatic Brain Injury

Traumatic brain injury is one of the leading causes of morbidity and mortality worldwide and is one of the major public healthcare burdens in the US, with millions of patients suffering from the traumatic brain injury itself (approximately 1.6 million/year) or its repercussions (2-6 million patients with disabilities). The severity of traumatic brain injury can range from mild transient neurological dysfunction or impairment to severe profound disability that leaves patients completely non-functional. Indications for treatment differ based on the injury's severity, but one of the goals of early treatment is to prevent secondary brain injury. Hemodynamic stability, monitoring and treatment of intracranial pressure, maintenance of cerebral perfusion pressure, support of adequate oxygenation and ventilation, administration of hyperosmolar agents and/or sedatives, nutritional support, and seizure prophylaxis are the mainstays of medical treatment for severe traumatic brain injury. Surgical management options include decompressive craniectomy or cerebrospinal fluid drainage via the insertion of an external ventricular drain. Several emerging treatment modalities are being investigated, such as anti-excitotoxic agents, anti-ischemic and cerebral dysregulation agents, S100B protein, erythropoietin, endogenous neuroprotectors, anti-inflammatory agents, and stem cell and neuronal restoration agents, among others.

Genetic diversity drives extreme responses to traumatic brain injury and post-traumatic epilepsy

Traumatic brain injury (TBI) is a complex and heterogeneous condition that can cause wide-spectral neurological sequelae such as behavioral deficits, sleep abnormalities, and post-traumatic epilepsy (PTE). However, understanding the interaction of TBI phenome is challenging because few animal models can recapitulate the heterogeneity of TBI outcomes. We leveraged the genetically diverse recombinant inbred Collaborative Cross (CC) mice panel and systematically characterized TBI-related outcomes in males from 12 strains of CC and the reference C57BL/6J mice. We identified unprecedented extreme responses in multiple clinically relevant traits across CC strains, including weight change, mortality, locomotor activity, cognition, and sleep. Notably, we identified CC031 mouse strain as the first rodent model of PTE that exhibit frequent and progressive post-traumatic seizures after moderate TBI induced by lateral fluid percussion. Multivariate analysis pinpointed novel biological interactions and three principal components across TBI-related modalities. Estimate of the proportion of TBI phenotypic variability attributable to strain revealed large range of heritability, including >70% heritability of open arm entry time of elevated plus maze. Our work provides novel resources and models that can facilitate genetic mapping and the understanding of the pathobiology of TBI and PTE.

Trends of anti-seizure medication prescribing pattern in traumatic brain injury patients for the prevention of posttraumatic seizure in Taiwan

Traumatic brain injury (TBI) patients are recommended to receive anti-seizure medication (ASM) as posttraumatic seizure (PTS) prophylaxis. However, the utilization of ASM, including the prescription patterns and associated clinical characteristics, is limited in Taiwan. Thus, this study aimed to investigate the ASM trends and clinical characteristics. This retrospective cohort study enrolled TBI patients who received levetiracetam, phenytoin, and valproic acid during hospitalization using the National Health Insurance Research Database between 2012 and 2019. The primary outcome was the trend of the ASMs based on the index year. The duration of levetiracetam prescription was categorized as short-term (seven days or less) or long-term (more than seven days). Logistic regression identified the factors associated with long-term usage. A total of 64,461 TBI patients were included. Levetiracetam usage increased yearly, while phenytoin declined. Among the levetiracetam users, 5681 (30.38%) were short-term users, and 13,016 (69.62%) were long-term users. Diagnoses of contusions, intracranial hemorrhage, other intracranial injuries, receiving operations, and a history of cerebrovascular disease were significantly associated with longer duration. Conclusions This study revealed the rising trend of levetiracetam usage, indicating its potential as an alternative to phenytoin. TBI patients with more severe conditions were more likely to receive longer prescriptions.

Applying Proteomics and Computational Approaches to Identify Novel Targets in Blast-Associated Post-Traumatic Epilepsy

Traumatic brain injury (TBI) can lead to post-traumatic epilepsy (PTE). Blast TBI (bTBI) found in Veterans presents with several complications, including cognitive and behavioral disturbances and PTE; however, the underlying mechanisms that drive the long-term sequelae are not well understood. Using an unbiased proteomics approach in a mouse model of repeated bTBI (rbTBI), this study addresses this gap in the knowledge. After rbTBI, mice were monitored using continuous, uninterrupted video-EEG for up to four months. Following this period, we collected cortex and hippocampus tissues from three groups of mice: those with post-traumatic epilepsy (PTE+), those without epilepsy (PTE-), and the control group (sham). Hundreds of differentially expressed proteins were identified in the cortex and hippocampus of PTE+ and PTE- relative to sham. Focusing on protein pathways unique to PTE+, pathways related to mitochondrial function, post-translational modifications, and transport were disrupted. Computational metabolic modeling using dysregulated protein expression predicted mitochondrial proton pump dysregulation, suggesting electron transport chain dysregulation in the epileptic tissue relative to PTE-. Finally, data mining enabled the identification of several novel and previously validated TBI and epilepsy biomarkers in our data set, many of which were found to already be targeted by drugs in various phases of clinical testing. These findings highlight novel proteins and protein pathways that may drive the chronic PTE sequelae following rbTBI.

Inflammation, brain connectivity, and neuromodulation in post-traumatic headache

Post-traumatic headache (PTH) is a debilitating condition that affects individuals with different levels of traumatic brain injury (TBI) severity. The difficulties in developing an effective treatment are related to a lack of understanding the complicated mechanisms and neurobiological changes in brain function after a brain injury. Preclinical studies have indicated that peripheral and central sensitization of the trigeminal nociceptive pathways contributes to PTH. While recent brain imaging studies have uncovered widespread changes in brain functional connectivity following trauma, understanding exactly how these networks contribute to PTH after injury remains unknown. Stimulation of peripheral (trigeminal or vagus) nerves show promising efficacies in PTH experimental animals, likely mediated by influencing TBI-induced pathological plasticity by decreasing neuroinflammation and neuronal apoptosis. Non-invasive brain stimulations, such as transcranial magnetic or direct current stimulations, show analgesia for multiple chronic pain conditions, including PTH. Better mechanistic understanding of analgesia achieved by neuromodulations can define peripheral and central mechanisms involved in the development, the resolution, and the management of PTH.

Assessing risk factors associated with breakthrough early post-traumatic seizures in patients receiving phenytoin prophylaxis

Objective

Post-traumatic seizure (PTS) is a well-known complication of traumatic brain injury (TBI). The objective of this study was to identify risk factors associated with breakthrough early PTS in TBI patients receiving phenytoin prophylaxis.

Methods

This was a single-centered retrospective study including adult patients admitted to the intensive care unit (ICU), had a TBI, and started on phenytoin for seizure prophylaxis within 24 h of admission. The primary outcome was the incidence and factors associated with early PTS, defined as a confirmed seizure on a continuous electroencephalogram within 7 days of TBI. Secondary outcomes included the association between early post-traumatic seizures and ICU length of stay, hospital length of stay, and in-hospital mortality.

Results

A total of 105 patients were included in the final analysis. Patients with early PTS were older (65 vs. 48 years old, p = 0.01), had a higher Marshall score (5 vs. 2, p = 0.01), were more likely to have a Marshall score > 2 (73 vs. 37%, p = 0.01), and had more neurosurgeries for hematoma evacuation (57 vs. 19%, p = 0.01). In patients with early PTS, 57% had a level at the time of seizure, and of those, 87.5% had a therapeutic level (>10 mcg/mL). Patients with early PTS had a longer ICU length of stay (14.7 vs. 5.9 days, p = 0.04) and a greater proportion of hospital mortality (21 vs. 2%, p = 0.02).

Conclusion

Patients with higher age, Marshall score, and neurosurgical procedures for hematoma evacuation had higher incidences of breakthrough early PTS despite the use of phenytoin prophylaxis. The majority of patients with early PTS had therapeutic phenytoin levels at the time of seizure when a level was available; however, approximately half (43%) did not have a level.

Tau Phosphorylation Patterns in the Rat Cerebral Cortex After Traumatic Brain Injury and Sodium Selenate Effects: An Epibios4rx Project 2 Study

Sodium selenate (SS) activates protein phosphatase 2 (PP2A) and reduces phosphorylated tau (pTAU) and late post-traumatic seizures after lateral fluid percussion injury (LFPI). In EpiBioS4Rx Project 2, a multi-center international study for post-traumatic targets, biomarkers, and treatments, we tested the target relevance and modification by SS of pTAU forms and PP2A and in the LFPI model, at two sites: Einstein and Melbourne. In Experiment 1, adult male rats were assigned to LFPI and sham (both sites) and naïve controls (Einstein). Motor function was monitored by neuroscores. Brains were studied with immunohistochemistry (IHC), Western blots (WBs), or PP2A activity assay, from 2 days to 8 weeks post-operatively. In Experiment 2, LFPI rats received SS for 7 days (SS0.33: 0.33 mg/kg/day; SS1: 1 mg/kg/day, subcutaneously) or vehicle (Veh) post-LFPI and pTAU, PR55 expression, or PP2A activity were studied at 2 days and 1 week (on treatment), or 2 weeks (1 week off treatment). Plasma selenium and SS levels were measured. In Experiment 1 IHC, LFPI rats had higher cortical pTAU-Ser202/Thr205-immunoreactivity (AT8-ir) and pTAU-Ser199/202-ir at 2 days, and pTAU-Thr231-ir (AT180-ir) at 2 days, 2 weeks, and 8 weeks, ipsilaterally to LFPI, than controls. LFPI-2d rats also had higher AT8/total-TAU5-ir in cortical extracts ipsilateral to the lesion (WB). PP2A (PR55-ir) showed time- and region-dependent changes in IHC, but not in WB. PP2A activity was lower in LFPI-1wk than in sham rats. In Experiment 2, SS did not affect neuroscores or cellular AT8-ir, AT180-ir, or PR55-ir in IHC. In WB, total cortical AT8/total-TAU-ir was lower in SS0.33 and SS1 LFPI rats than in Veh rats (2 days, 1 week); total cortical PR55-ir (WB) and PP2A activity were higher in SS1 than Veh rats (2 days). SS dose dependently increased plasma selenium and SS levels. Concordant across-sites data confirm time and pTAU form-specific cortical increases ipsilateral to LFPI. The discordant SS effects may either suggest SS-induced reduction in the numbers of cells with increased pTAU-ir, need for longer treatment, or the involvement of other mechanisms of action.

Celecoxib treatment alleviates cerebral injury in a rat model of post-traumatic epilepsy

Background

An important factor contributing to the development and occurrence of post-traumatic epilepsy (PTE) is neuroinflammation and oxidative stress. The effects of celecoxib include inhibiting inflammatory reactions and antioxidant stress and reducing seizures, making it a potential epilepsy treatment solution.

Objective

To observe the effect of celecoxib on early epilepsy in post-traumatic epilepsy rats. Methods: Twenty-four adult healthy male Sprague-Dawley rats were randomly assigned to three groups: sham-operated, PTE, and celecoxib. A rat model of PTE was established by injecting ferrous chloride into the right frontal cortex. Afterward, the behavior of rats was observed and recorded. 3.0T superconducting magnetic resonance imaging (MRI) was used to describe the changes in ADC values of the brain. HE and Nissl staining were also used to detect the damage to frontal lobe neurons. Furthermore, the expression of COX-2 protein in the right frontal lobe was detected by Western blot. Moreover, the contents of IL-1 and TNF-α in the right frontal lobe were detected by enzyme-linked immunosorbent assay.

Results

Compared with the PTE group, the degree of seizures in rats treated with celecoxib declined dramatically (P < 0.05). Celecoxib-treated rats had significant decreases in tissue structural damage and cell death in the brain. The results of the MRI showed that celecoxib reduced the peripheral edema zone and ADC value of the cortex around the damaged area of the right frontal lobe in the celecoxib-treatment group, which was significantly decreased compared with the PTE group (P < 0.05). Furthermore, celecoxib decreased the expression of COX-2, IL-1β, and TNF-α in brain tissue (P < 0.05).

Conclusions

In PTE rats, celecoxib significantly reduced brain damage and effectively reduced seizures. As a result of celecoxib's ability to inhibit inflammation, it can reduce the edema caused by injury in rat brain tissue.

Association between pediatric traumatic brain injury and epilepsy at later ages in Finland: A nationwide register-based cohort study

OBJECTIVE

This study was undertaken to examine how pediatric traumatic brain injury (pTBI) correlates with incidence of epilepsy at later ages in Finland.

METHODS

This nationwide retrospective register-based cohort study extended from 1998 to 2018. The study group consisted of 71 969 pediatric (<18 years old) patients hospitalized with TBI and a control group consisting of 64 856 pediatric patients with distal extremity fracture. Epilepsy diagnoses were gathered from the Finnish Social Insurance Institution. Kaplan-Meier and multivariable Cox regression models were conducted to analyze the probability of epilepsy with 95% confidence intervals (CIs).

RESULTS

Cumulative incidence rates (CIRs) for the first 2 years were .5% in the pTBI group and .1% in the control group. The corresponding rates after 15 years of follow-up were 1.5% in the pTBI group and .7% in the control group. Due to proportional hazard violations, the study population was split to the first 2 years and in subgroup analysis 4 years. During the first 2 years of surveillance, the hazard ratio (HR) for the pTBI group was 4.38 (95% CI = 3.39-5.66). However, between years 2 and 20, the HR for the pTBI group was 2.02 (95% CI = 1.71-2.38). A total of 337 patients (.47%) underwent neurosurgery, and 36 (10.7%) patients subsequently developed epilepsy. The CIR for the first year after TBI was 4.5% (95% CI = 2.3-6.7) in operatively managed patients and .3% (95% CI = .3-.4) in nonoperatively managed patients. Corresponding figures after 15 years were 12.0% (95% CI = 8.2-15.8) and 1.5% (95% CI = 1.4-1.6). During the first 4 years of surveillance, the HR for the operative pTBI group was 14.37 (95% CI = 9.29-20.80) and 3.67 (95% CI = 1.63-8.22) between years 4 and 20.

SIGNIFICANCE

pTBI exposes patients to a higher risk for posttraumatic epilepsy for many years after initial trauma. Children who undergo operative management for TBI have a high risk for epilepsy, and this risk was highest during the first 4 years after injury.

Discontinuation of Levetiracetam and Valproic Acid Due to Adverse Effects in Early Post-traumatic Seizure Prophylaxis

INTRODUCTION

Levetiracetam (LEV) and valproic acid (VPA) are two anti-epileptic drugs (AEDs) routinely used for post-traumatic seizure (PTS) prophylaxis at our institution. In our practice, VPA is used for its beneficial effects on behavioral agitation and headaches, but it is also associated with abnormal liver function tests (LFTs). Both medications may be associated with thrombocytopenia. There is less literature comparing the adverse effect profiles and discontinuation rates of LEV and VPA in the context of PTS prophylaxis. We conducted a quality improvement (QI) analysis to determine the safety of LEV and VPA for traumatic brain injury (TBI) patients at our institution. In particular, our QI analysis involved calculating the rates of discontinuation or change of drug regimen due to the adverse effects.

METHODS

Our QI analysis focused on patients treated for TBI at our institution during a six-year period. We recorded the AED used and if the AED was discontinued or switched due to thrombocytopenia, behavioral agitation, headaches, or elevated LFTs (including elevated aspartate aminotransferase or alanine aminotransferase values). We also recorded the incidence of early PTS, defined as seizures within seven days of the TBI.

RESULTS

Our QI analysis included patients with a mean age of approximately 49 years with nearly 75% males. The mean Glasgow Coma Scale (GCS) score was 12.88, with 73.11% of patients having a mild GCS. The three leading injury mechanisms were fall, assault, and motor vehicle collision. The three leading types of TBI were traumatic subarachnoid hemorrhage, subdural hematoma, and cerebral contusion. Among patients with no prior history of seizures, we found an early PTS incidence of 7.28%. For patients administered LEV and VPA, 0.11% (1/898) and 3.85% (4/104) had the medication discontinued or changed because of thrombocytopenia (p < 0.001), respectively. For patients on LEV, 4.01% (36/898) and 1.78% (16/898) had the medication discontinued or changed because of behavioral agitation and headaches, respectively. For patients on VPA, 2.88% (3/104) had the medication discontinued or changed because of hepatotoxicity. In total, 5.90% versus 6.73% (p > 0.5) of patients on LEV and VPA, respectively, had their medication regimens changed due to the adverse effects.

CONCLUSIONS

The incidence of early PTS in our patients is within the range of what has been reported in the literature. The rate of discontinuation of LEV and VPA on account of adverse events is low in the context of PTS prophylaxis. Both medications had similar overall rates of discontinuation. VPA was discontinued more frequently than LEV due to thrombocytopenia, but discontinuation was not common in either case. LEV is associated with behavioral agitation and headaches, which makes VPA a desirable alternative for patients suffering from these symptoms.

Treatment of Status Epilepticus after Traumatic Brain Injury Using an Antiseizure Drug Combined with a Tissue Recovery Enhancer Revealed by Systems Biology

We tested a hypothesis that in silico-discovered compounds targeting traumatic brain injury (TBI)-induced transcriptomics dysregulations will mitigate TBI-induced molecular pathology and augment the effect of co-administered antiseizure treatment, thereby alleviating functional impairment. In silico bioinformatic analysis revealed five compounds substantially affecting TBI-induced transcriptomics regulation, including calpain inhibitor, chlorpromazine, geldanamycin, tranylcypromine, and trichostatin A (TSA). In vitro exposure of neuronal-BV2-microglial co-cultures to compounds revealed that TSA had the best overall neuroprotective, antioxidative, and anti-inflammatory effects. In vivo assessment in a rat TBI model revealed that TSA as a monotherapy (1 mg/kg/d) or in combination with the antiseizure drug levetiracetam (LEV 150 mg/kg/d) mildly mitigated the increase in plasma levels of the neurofilament subunit pNF-H and cortical lesion area. The percentage of rats with seizures during 0-72 h post-injury was reduced in the following order: TBI-vehicle 80%, TBI-TSA (1 mg/kg) 86%, TBI-LEV (54 mg/kg) 50%, TBI-LEV (150 mg/kg) 40% (p < 0.05 vs. TBI-vehicle), and TBI-LEV (150 mg/kg) combined with TSA (1 mg/kg) 30% (p < 0.05). Cumulative seizure duration was reduced in the following order: TBI-vehicle 727 ± 688 s, TBI-TSA 898 ± 937 s, TBI-LEV (54 mg/kg) 358 ± 715 s, TBI-LEV (150 mg/kg) 42 ± 64 (p < 0.05 vs. TBI-vehicle), and TBI-LEV (150 mg/kg) combined with TSA (1 mg/kg) 109 ± 282 s (p < 0.05). This first preclinical intervention study on post-TBI acute seizures shows that a combination therapy with the tissue recovery enhancer TSA and LEV was safe but exhibited no clear benefit over LEV monotherapy on antiseizure efficacy. A longer follow-up is needed to confirm the possible beneficial effects of LEV monotherapy and combination therapy with TSA on chronic post-TBI structural and functional outcomes, including epileptogenesis.

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.

Delayed treatment with ceftriaxone reverses the enhanced sensitivity of TBI mice to chemically-induced seizures

The pathophysiological changes that occur after traumatic brain injury (TBI) can lead to the development of post-traumatic epilepsy, a life-long complication of brain trauma. The etiology of post-traumatic epilepsy remains unknown, but TBI brains exhibit an abnormal excitatory / inhibitory balance. In this study, we examine how brain injury alters susceptibility to chemically-induced seizures in C57Bl/6J mice, and if pharmacological enhancement of glutamate transporters can reduce chronic post-traumatic seizures. We found that controlled cortical impact (CCI) mice display delayed susceptibility to pentylenetetrazol (PTZ)-induced seizures. While CCI mice have no change in seizure susceptibility at 7d post-injury (dpi), at 70dpi they have reduced latency to PTZ-induced seizure onset, higher seizure frequency and longer seizure duration. Quantification of glutamate transporter mRNA showed that levels of Scl1a2 and Scl1a3 mRNA were increased at 7dpi, but significantly decreased at 70dpi. To test if increased levels of glutamate transporters can ameliorate delayed-onset seizure susceptibility in TBI mice, we exposed a new cohort of mice to CCI and administered ceftriaxone (200mg/kg/day) for 14d from 55-70dpi. We found that ceftriaxone significantly increased Scl1a2 and Scl1a3 in CCI mouse brain at 70dpi, and prevented the susceptibility of CCI mice to PTZ-induced seizures. This study demonstrates cortical impact can induce a delayed-onset seizure phenotype in mice. Delayed (55dpi) ceftriaxone treatment enhances glutamate transporter mRNA in the CCI brain, and reduces PTZ-induced seizures in CCI mice.

Atypical Neurogenesis, Astrogliosis, and Excessive Hilar Interneuron Loss Are Associated with the Development of Post-Traumatic Epilepsy

BACKGROUND

Traumatic brain injury (TBI) remains a significant risk factor for post-traumatic epilepsy (PTE). The pathophysiological mechanisms underlying the injury-induced epileptogenesis are under investigation. The dentate gyrus-a structure that is highly susceptible to injury-has been implicated in the evolution of seizure development.

METHODS

Utilizing the murine unilateral focal control cortical impact (CCI) injury, we evaluated seizure onset using 24/7 EEG video analysis at 2-4 months post-injury. Cellular changes in the dentate gyrus and hilus of the hippocampus were quantified by unbiased stereology and Imaris image analysis to evaluate Prox1-positive cell migration, astrocyte branching, and morphology, as well as neuronal loss at four months post-injury. Isolation of region-specific astrocytes and RNA-Seq were performed to determine differential gene expression in animals that developed post-traumatic epilepsy (PTE+) vs. those animals that did not (PTE-), which may be associated with epileptogenesis.

RESULTS

CCI injury resulted in 37% PTE incidence, which increased with injury severity and hippocampal damage. Histological assessments uncovered a significant loss of hilar interneurons that coincided with aberrant migration of Prox1-positive granule cells and reduced astroglial branching in PTE+ compared to PTE- mice. We uniquely identified Cst3 as a PTE+-specific gene signature in astrocytes across all brain regions, which showed increased astroglial expression in the PTE+ hilus.

CONCLUSIONS

These findings suggest that epileptogenesis may emerge following TBI due to distinct aberrant cellular remodeling events and key molecular changes in the dentate gyrus of the hippocampus.

Repetitive Transcranial Magnetic Stimulation and Rehabilitation Therapy for Upper Limb Hemiparesis in Stroke Patients: A Narrative Review

Recent technological advances in non-invasive brain stimulation (NIBS) have led to the development of therapies for post-stroke upper extremity paralysis. Repetitive transcranial magnetic stimulation (rTMS), a NIBS technique, controls regional activity by non-invasively stimulating selected areas of the cerebral cortex. The therapeutic principle by which rTMS is thought to work is the correction of interhemispheric inhibition imbalances. The guidelines for rTMS for post-stroke upper limb paralysis have graded it as a highly effective treatment, and, based on functional brain imaging and neurophysiological testing, it has been shown to result in progress toward normalization. Our research group has published many reports showing improvement in upper limb function after administration of the NovEl Intervention Using Repetitive TMS and intensive one-to-one therapy (NEURO), demonstrating its safety and efficacy. Based on the findings to date, rTMS should be considered as a treatment strategy based on a functional assessment of the severity of upper extremity paralysis (Fugl-Meyer Assessment), and NEURO should be combined with pharmacotherapy, botulinum treatment, and extracorporeal shockwave therapy to maximize therapeutic effects. In the future, it will be important to establish tailormade treatments in which stimulation frequency and sites are adjusted according to the pathological conditions of interhemispheric imbalance, as revealed by functional brain imaging.

Efficacy of 48 hours dose of phenytoin in prevention of early post-traumatic seizure

Background

Antiseizure medications, such as phenytoin sodium, have been shown in some reports to reduce the incidence of early post-traumatic seizure. These medications, however, are not without side effects which may be dose related or duration related. The risks associated with short-term therapy are minimal and often dose related (and hence avoidable). This study intends to determine the efficacy of a short-course (48-hour dose) of phenytoin in prevention of early post-traumatic seizure.

Methods

This was a prospective randomised double-blind clinical intervention study. Head injured patients presenting within the first 24 hours were randomly assigned to either 48-hour dose of phenytoin or control groups, and were observed for clinical seizure over a week. The difference in the incidences of early post-traumatic seizure between the two groups was determined by χ² test. A p<0.05 was considered as statistically significant.

Results

A total of 94 patients were included in the study, 47 each in the control group and the phenytoin group. There were 77 males and 17 female (M:F 4.5:1). Both groups had similar demographic and clinical profile. The incidence of seizure was 21.3% in the control but 2.1% in the treatment arm (p<0.01). All seizures occurred within 24 hours of trauma in the control, while the only episode of seizure in the treatment group occurred later.

Conclusion

A short-course (48-hour dose) of phenytoin might be an effective prophylactic treatment to reduce the incidence of early post-traumatic seizure.

A prospective study to determine the risk factors associated with post traumatic seizures: A single institution experience

Background

Post traumatic seizures (PTS) are a known sequel of traumatic brain injury (TBI). Incidence of PTS is dependent on many factors including study design and characteristics of the study population. As incidence of TBI increases and death due to TBI decreases, more individuals will be at risk of developing and living with chronic complications. The objective of the present study was to determine the frequency and risk factors for PTS following TBI.

Methods

A prospective study was conducted on patients admitted with TBI from April 1, 2019, to May 31, 2020, to determine the frequency, time to event, and risk factors for PTS following TBI. We classified the severity of head injury using a standard criterion, into mild, moderate and severe injury. Follow-up of 3 months was undertaken for all patients. Variables include age, sex, trauma severity, Glasgow coma scale, onset of PTS, and neuroradiological finding.

Results

We enrolled 450 post traumatic subjects, out of which 36 (8%) developed seizures. Of the total of 36 patients detected to have hemorrhagic contusion on computerized tomography scan, 12 patients developed seizures. We found that the independent risk factors associated with occurrence of PTS were frontal- temporal lobar contusion and severity of head injury. All these findings were statistically significant.

Conclusion

We found that the independent risk factors associated with occurrence of PTS were frontal-temporal lobar contusion and severity of head injury. Type of management (Operative vs. Non operative) does not affect the outcome of PTS.

Use of Anti-epileptic Drugs for Post Traumatic Seizure: A Global Survey

BACKGROUND

Post traumatic seizures (PTS) and post traumatic epilepsy (PTE) are potential consequences of traumatic brain injury (TBI). There is no consensus regarding its management among treating doctors.

PURPOSE

We have undertaken a global survey to assess the variability of management practices of PTS and PTE and highlight the pressing need to formulate uniform practice guidelines.

METHODS

A questionnaire consisting of sixteen questions were developed with the help of Google survey and sent through e-mail, or social media platforms like WhatsApp, Facebook messenger or Telegram, to practicing Neurologists and Neurosurgeons round the world.

RESULTS

There were a total of 220 responses. Majority of our responders (n = 202; 91.8%) would start an anti-epileptic (AED) prophylaxis to prevent PTS; 18 people (8.18%) told that they would not start AED prophylaxis for TBI. Phenytoin (n = 98; 48.5%) followed by Levetiracetam (n = 78; 38.6%) was the preferred drug, although the latter was significantly preferred by high and upper middle-income countries (p<.001). Majority (n = 99; 49%) would not use it beyond two weeks. Most clinicians would manage PTE with a single drug (n = 160; 72.7%) either Phenytoin (n = 69; 31.3%) or levetiracetam (n = 67; 30.4%). Most of them (n = 174; 86%) would treat for less than one year.

CONCLUSIONS

Practices in the management of PTS and PTE vary widely among clinicians. Our study point towards the need for the development of a more robust and comprehensive practice guidelines for the management of the same.

Chemical Kindling as an Experimental Model to Assess the Conventional Drugs in the Treatment of Post-traumatic Epilepsy

BACKGROUND

Traumatic brain injury (TBI) is one of the leading causes of morbidity and mortality today, which will surpass many infectious diseases in the coming years/decades. Posttraumatic epilepsy (PTE) is one of the most common debilitating consequences of TBI. PTE is a secondary, acquired epilepsy that causes recurrent, spontaneous seizures more than a week after TBI. The extent of head injury in individuals who develop PTE is unknown; however, trauma is thought to account for 20% of symptomatic epilepsy worldwide. Understanding the mechanisms of epilepsy following TBI is crucial for the discovery of new anticonvulsant drugs for the treatment of PTE, as well as for improving the quality of life of patients with PTE.

OBJECTIVE

This review article explains the rationale for the usage of a chemical model to access new treatments for post-traumatic epilepsy.

RESULTS

There are multiple methods to control and manage PTE. The essential and available remedy for the management of epilepsy is the use of antiepileptic drugs. Antiepileptic drugs (AEDs) decrease the frequency of seizures without affecting the disease's causality. Antiepileptic drugs are administrated for the prevention and treatment of PTE; however, 30% of epilepsy patients are drug-resistant, and AED side effects are significant in PTE patients. There are different types of animal models, such as the liquid percussion model, intracortical ferric chloride injection, and cortical subincision model, to study PTE and neurophysiological mechanisms underlying the development of epilepsy after head injury. However, these animal models do not easily mimic the pathological events occurring in epilepsy. Therefore, animal models of PTE are an inappropriate tool for screening new and putatively effective AEDs. Chemical kindling is the most common animal model used to study epilepsy. There is a strong similarity between the kindling model and different types of human epilepsy.

CONCLUSION

Today, researchers use experimental animal models to evaluate new anticonvulsant drugs. The chemical kindling models, such as pentylenetetrazol, bicuculline, and picrotoxin-induced seizures, are important experimental models to analyze the impact of putative antiepileptic drugs.

Establishment and validation of PTE prediction model in patients with cerebral contusion

Post-traumatic epilepsy (PTE) is an important cause of poor prognosis in patients with cerebral contusions. The primary purpose of this study is to evaluate the high-risk factors of PTE by summarizing and analyzing the baseline data, laboratory examination, and imaging features of patients with a cerebral contusion, and then developing a Nomogram prediction model and validating it. This study included 457 patients diagnosed with cerebral contusion who met the inclusion criteria from November 2016 to November 2019 at the Qinghai Provincial People's Hospital. All patients were assessed for seizure activity seven days after injury. Univariate analysis was used to determine the risk factors for PTE. Significant risk factors in univariate analysis were selected for binary logistic regression analysis. P < 0.05 was statistically significant. Based on the binary logistic regression analysis results, the prediction scoring system of PTE is established by Nomogram, and the line chart model is drawn. Finally, external validation was performed on 457 participants to assess its performance. Univariate and binary logistic regression analyses were performed using SPSS software, and the independent predictors significantly associated with PTE were screened as Contusion site, Chronic alcohol use, Contusion volume, Skull fracture, Subdural hematoma (SDH), Glasgow coma scale (GCS) score, and Non late post-traumatic seizure (Non-LPTS). Based on this, a Nomogram model was developed. The prediction accuracy of our scoring system was C-index = 98.29%. The confidence interval of the C-index was 97.28% ~ 99.30%. Internal validation showed that the calibration plot of this model was close to the ideal line. This study developed and verified a highly accurate Nomogram model, which can be used to individualize PTE prediction in patients with a cerebral contusion. It can identify individuals at high risk of PTE and help us pay attention to prevention in advance. The model has a low cost and is easy to be popularized in the clinic. This model still has some limitations and deficiencies, which need to be verified and improved by future large-sample and multicenter prospective studies.

Early post-traumatic seizures in hospitalized patients with traumatic brain injury

OBJECTIVES

Early post-traumatic seizures (EPTS) are a well-known complication of traumatic brain injury (TBI). EPTS increase the risk of secondary brain injury and may cause significant challenges during the period of critical care. Routine use of prophylactic anti-seizure medication is controversial due to conflicting reports on efficacy and risk of adverse effects. The purpose of this study was to expand the understanding of EPTS by examining incidence and risk factors in hospitalized patients with TBI.

MATERIAL & METHODS

Adult patients with TBI and evidence of intracranial injury admitted to Oslo University Hospital between 2015 and 2019 were identified from the Oslo TBI Registry - Neurosurgery. Demographic and clinical data including occurrence of seizures were retrieved from the registry. The patients did not receive routine seizure prophylaxis. Univariate and multivariable logistic regression analyses were used to investigate risk factors associated with EPTS.

RESULTS

103 of 1827 patients (5.6%) had new-onset seizures within the first week after TBI. The following factors were in multivariable analyses associated with EPTS; alcohol abuse (odds ratio [OR] 3.6, 95% CI 2.3-5.7, p < .001), moderate and severe brain injury (OR 2.2, 95% CI 1.3-3.8, p = .004 and OR 2.1, 95% CI 1.2-3.6, p = .012), brain contusion (OR 1.6, 95% CI 1.0-2.4, p = .046) and subdural hematoma (OR 1.6, 95% CI 1.0-2.6, p = .052).

CONCLUSION

In our material, EPTS occurred in 5.6% of hospital-admitted TBI-patients. Alcohol abuse was the most significant risk factor, followed by moderate and severe brain injury. The results of this study contribute to the discussion about preventive treatment of EPTS in certain risk groups.

Differential Patterns of Change in Brain Connectivity Resulting from Severe Traumatic Brain Injury

Background: Traumatic brain injury (TBI) damages white matter tracts, disrupting brain network structure and communication. There exists a wide heterogeneity in the pattern of structural damage associated with injury, as well as a large heterogeneity in behavioral outcomes. However, little is known about the relationship between changes in network connectivity and clinical outcomes. Materials and Methods: We utilize the rat lateral fluid-percussion injury model of severe TBI to study differences in brain connectivity in 8 animals that received the insult and 11 animals that received only a craniectomy. Diffusion tensor imaging is performed 5 weeks after the injury and network theory is used to investigate changes in white matter connectivity. Results: We find that (1) global network measures are not able to distinguish between healthy and injured animals; (2) injury induced alterations predominantly exist in a subset of connections (subnetworks) distributed throughout the brain; and (3) injured animals can be divided into subgroups based on changes in network motifs-measures of local structural connectivity. In addition, alterations in predicted functional connectivity indicate that the subgroups have different propensities to synchronize brain activity, which could relate to the heterogeneity of clinical outcomes. Discussion: These results suggest that network measures can be used to quantify progressive changes in brain connectivity due to injury and differentiate among subpopulations with similar injuries, but different pathological trajectories.

Transcriptome Profiling of the Hippocampal Seizure Network Implicates a Role for Wnt Signaling during Epileptogenesis in a Mouse Model of Temporal Lobe Epilepsy

Mesial temporal lobe epilepsy (mTLE) is a life-threatening condition characterized by recurrent hippocampal seizures. mTLE can develop after exposure to risk factors such as febrile seizure, trauma, and infection. Within the latent period between exposure and onset of epilepsy, pathological remodeling events occur that contribute to epileptogenesis. The molecular mechanisms responsible are currently unclear. We used the mouse intrahippocampal kainite model of mTLE to investigate transcriptional dysregulation in the ipsilateral and contralateral dentate gyrus (DG), representing the epileptogenic zone (EZ) and peri-ictal zone (PIZ). DG were analyzed after 3, 7, and 14 days by RNA sequencing. In both the EZ and PIZ, transcriptional dysregulation was dynamic over the epileptogenic period with early expression of genes representing cell signaling, migration, and proliferation. Canonical Wnt signaling was upregulated in the EZ and PIZ at 3 days. Expression of inflammatory genes differed between the EZ and PIZ, with early expression after 3 days in the PIZ and delayed expression after 7-14 days in the EZ. This suggests that critical gene changes occur early in the hippocampal seizure network and that Wnt signaling may play a role within the latent epileptogenic period. These findings may help to identify novel therapeutic targets that could prevent epileptogenesis.

Initial neurocritical care of severe traumatic brain injury: New paradigms and old challenges

Background:

Early neurocritical care aims to ameliorate secondary traumatic brain injury (TBI) and improve neural salvage. Increased engagement of neurosurgeons in neurocritical care is warranted as daily briefings between the intensivist and the neurosurgeon are considered a quality indicator for TBI care. Hence, neurosurgeons should be aware of the latest evidence in the neurocritical care of severe TBI (sTBI).

Methods:

We conducted a narrative literature review of bibliographic databases (PubMed and Scopus) to examine recent research of sTBI.

Results:

This review has several take-away messages. The concept of critical neuroworsening and its possible causes is discussed. Static thresholds of intracranial pressure (ICP) and cerebral perfusion pressure may not be optimal for all patients. The use of dynamic cerebrovascular reactivity indices such as the pressure reactivity index can facilitate individualized treatment decisions. The use of ICP monitoring to tailor treatment of intracranial hypertension (IHT) is not routinely feasible. Different guidelines have been formulated for different scenarios. Accordingly, we propose an integrated algorithm for ICP management in sTBI patients in different resource settings. Although hyperosmolar therapy and decompressive craniectomy are standard treatments for IHT, there is a lack high-quality evidence on how to use them. A discussion of the advantages and disadvantages of invasive ICP monitoring is included in the study. Addition of beta-blocker, anti-seizure, and anticoagulant medications to standardized management protocols (SMPs) should be considered with careful patient selection.

Conclusion:

Despite consolidated research efforts in the refinement of SMPs, there are still many unanswered questions and novel research opportunities for sTBI care.

Biperiden for prevention of post-traumatic epilepsy: A protocol of a double-blinded placebo-controlled randomized clinical trial (BIPERIDEN trial)

Background

Traumatic brain injury (TBI) is one of the most important causes of acquired structural epilepsy, post-traumatic epilepsy (PTE), however, efficient preventative measures and treatment are still not available to patients. Preclinical studies indicated biperiden, an anticholinergic drug, as a potential drug to modify the epileptogenic process. The main objective of this clinical trial is to evaluate the efficacy of biperiden as an antiepileptogenic agent in patients that suffered TBI.

Methods

This prospective multicenter (n = 10) interventional study will include 312 adult patients admitted to emergency care units with a diagnosis of moderate or severe TBI. Following inclusion and exclusion criteria, patients will be randomized, using block randomization, to receive double-blind treatment with placebo or biperiden for 10 days. Follow-up will occur at specific time windows up to 2 years. Main outcomes are incidence of PTE after TBI and occurrence of severe adverse events. Other outcomes include exploratory investigation of factors that might have benefits for the treatment or might influence its results, such as genetic background, clinical progression, electroencephalographic abnormalities, health-related quality of life and neuropsychological status. Analyses will be conducted following the safety, intention-to-treat and efficacy concepts.

Discussion

We hypothesize that biperiden treatment will be effective to prevent or mitigate the development of post-traumatic epilepsy in TBI patients. Other health measures from this population also may benefit from treatment with biperiden.

Trial registration

ClinicalTrials.gov, NCT04945213. Registered on June 30, 2021.

Pharmacokinetic considerations surrounding the use of levetiracetam for seizure prophylaxis in neurocritical care - an overview

INTRODUCTION

Levetiracetam (LEV) is one of the most widely used anti-seizure medications (ASMs) in clinical practice. This is due both to a different mechanism of action when compared to other ASMs and its easy handling. Indeed, because of its interesting pharmacokinetic properties, it is often used outside of the labelled indications, notably in the neurocritical setting as prophylaxis of epileptic seizures.

AREAS COVERED

A literature search was conducted and the most relevant studies on the pharmacokinetic properties of LEV were selected by two independent investigators. Current evidence on the use of ASM prophylaxis in the neurocritical setting was also reviewed, highlighting and discussing the strengths and limits of LEV as drug of choice for anti-epileptic prophylaxis in this scenario.

EXPERT OPINION

LEV has a "near-ideal" pharmacokinetic profile, which makes it an attractive drug for ASM prophylaxis in neurocritical care. However, current recommendations restrict ASMs prophylaxis to very selected circumstances and the role of LEV is marginal. Moreover, studies are generally designed to compare LEV versus phenytoin, whereas studies comparing LEV versus placebo are lacking. Further randomized trials will be needed to better elucidate LEV utility and its neuroprotective role in the neurocritical setting.

Posttraumatic epilepsy: A single institution case series in Indonesia

Background:

Posttraumatic epilepsy (PTE) is a debilitating sequelae following traumatic brain injury (TBI). Risk of developing PTE is higher in the first 6 months following head trauma and remains increased for 10 years. Many cases of PTE developed into drug-resistant epilepsy in which need surgical treatment.

Case Description:

Fourteen patients were identified from 1998 until 2021. Mean age at onset was 21.00 ± 6.13 years, mean age of surgery was 29.50 ± 6.83 years. All patients had partial complex seizure with more than half of cases (n = 10, 71.4%) reported with focal impaired awareness seizure and focal to bilateral tonic–clonic type of seizure which were observed in the remained cases (n = 4, 28.6%). Abnormal magnetic resonance imaging findings were observed in 12 patients: mesial temporal sclerosis (n = 7), encephalomalacia (n = 4), brain atrophy (n = 4), and focal cortical dysplasia (n = 2). More than half of cases presented with mesial temporal lobe epilepsy despite site and type of brain injury. Most patients who undergone epileptogenic focus resection were free of seizure, but two patients remained to have seizure with worthwhile improvement.

Conclusion:

This study emphasizes the clinical characteristic of PTE cases in our center in Indonesia. While encephalomalacia is a typical finding following TBI and often responsible for epilepsy, electroencephalogram recording remains critical in determining epileptic focus. Most of PTE patients presented with temporal lobe epilepsy had excellent outcomes after surgical resection of epileptogenic focus.

Risk factors for Drug-resistant Epilepsy (DRE) and a nomogram model to predict DRE development in post-traumatic epilepsy patients

Objectives

To identify factors affecting the development of drug‐resistant epilepsy (DRE), and establish a reliable nomogram to predict DRE development in post‐traumatic epilepsy (PTE) patients.

Methods

This study conducted a retrospective clinical analysis in patients with PTE who visited the Epilepsy Center, Beijing Tiantan Hospital from January 2013 to December 2018. All participants were followed up for at least 3 years, and the development of DRE was assessed. Data from January 2013 to December 2017 were used as development dataset for model building. Those independent predictors of DRE were included in the final multivariable logistic regression, and a derived nomogram was built. Data from January 2018 to December 2018 were used as validation dataset for internal validation.

Results

Complete clinical information was available for 2830 PTE patients (development dataset: 2023; validation dataset: 807), of which 21.06% (n = 596) developed DRE. Among all parameters of interest including gender, age at PTE, family history, severity of traumatic brain injury (TBI), single or multiple injuries, lesion location, post‐TBI treatments, acute seizures, PTE latency, seizure type, status epilepticus (SE), and electroencephalogram (EEG) findings, four predictors showed independent effect on DRE, they were age at PTE, seizure type, SE, and EEG findings. A model incorporating these four variables was created, and a nomogram to calculate the probability of DRE using the coefficients of the model was developed. The C‐index of the predictive model and the validation was 0.662 and 0.690, respectively. The goodness‐of‐fit test indicated good calibration for model development and validation (p = 0.272, 0.572).

Conclusions

The proposed nomogram achieved significant potential for clinical utility in the prediction of DRE among PTE patients. The risk of DRE for individual PTE patients can be estimated by using this nomogram, and identified high‐risk patients might benefit from non‐pharmacological therapies at an early stage.

Incidence and predictors of epilepsy in children with congenital heart disease

OBJECTIVE

Children with CHD may be at increased risk for epilepsy. While the incidence of perioperative seizures after surgical repair of CHD has been well-described, the incidence of epilepsy is less well-defined. We aim to determine the incidence and predictors of epilepsy in patients with CHD.

METHODS

Retrospective cohort study of patients with CHD who underwent cardiopulmonary bypass at <2 years of age between January, 2012 and December, 2013 and had at least 2 years of follow-up. Clinical variables were extracted from a cardiac surgery database and hospital records. Seizures were defined as acute if they occurred within 7 days after an inciting event. Epilepsy was defined based on the International League Against Epilepsy criteria.

RESULTS

Two-hundred and twenty-one patients were identified, 157 of whom were included in our analysis. Five patients (3.2%) developed epilepsy. Acute seizures occurred in 12 (7.7%) patients, only one of whom developed epilepsy. Predictors of epilepsy included an earlier gestational age, a lower birth weight, a greater number of cardiac surgeries, a need for extracorporeal membrane oxygenation or a left ventricular assist device, arterial ischaemic stroke, and a longer hospital length of stay.

CONCLUSIONS

Epilepsy in children with CHD is rare. The mechanism of epileptogenesis in these patients may be the result of a complex interaction of patient-specific factors, some of which may be present even before surgery. Larger long-term follow-up studies are needed to identify risk factors associated with epilepsy in these patients.

Delayed-Onset Seizures Following Self-Inflicted Nail Gun Injury to the Head: A Case Report and Literature Review

Nail gun use and its associated incidence of injury have continued to increase since it was first introduced in 1959. While most of these injuries involve the extremities, a subset of patients suffer intracranial trauma. The most recent comprehensive review on this particular subject referenced 41 cases and advocated for further discussion regarding proper treatment plans for these individuals. We present the case of a 25-year-old who suffered 35 self-inflicted penetrating head wounds from a nail gun after suffering an amputation injury at his job site. No neurological deficits were present on his arrival to the emergency room. He underwent surgery to treat his arm wound and remove 13 of the 35 nails. The patient was discharged from the hospital on levetiracetam and made a full recovery. Nearly 1 year later, he experienced a seizure at his workplace. However, after resuming his antiepileptic medication, he reports no further complications. This case is distinct for not only being the most nails in a patient's head at presentation, but also following surgery. Utilizing this case, prior review, and 27 subsequent cases, we propose an updated algorithm for diagnosis and treatment of nail-gun-related penetrating head trauma.

Comparative efficacy of prophylactic anticonvulsant drugs following traumatic brain injury: A systematic review and network meta-analysis of randomized controlled trials

We systematically compared the effects of prophylactic anticonvulsant drug use in patients with traumatic brain injury. We searched four electronic databases from their inception until July 13, 2021. Two researchers independently screened, appraised, and extracted the included studies. Network meta-analysis using multivariate random effects and a frequentist framework was adopted for data analysis. The risk of bias of each study was assessed using the Cochrane risk of bias tool, and confidence in evidence was assessed through confidence in network meta-analysis (CINeMA). A total of 11 randomized controlled trials involving 2,450 participants and six different treatments (i.e., placebo, carbamazepine, phenytoin, levetiracetam, valproate, and magnesium sulfate) were included. We found that anticonvulsant drugs as a whole significantly reduced early posttraumatic seizures (PTS) but not late PTS compared with placebo (odd ratios [ORs] = 0.42 and 0.82, 95% confidence intervals [CIs] = 0.21–0.82 and 0.47–1.43). For the findings of network meta-analysis, we observed that phenytoin (ORs = 0.43 and 0.71; 95% CIs = 0.18–1.01 and 0.23–2.20), levetiracetam (ORs = 0.56 and 1.58; 95% CIs = 0.12–2.55 and 0.03–84.42), and carbamazepine (ORs = 0.29 and 0.64; 95% CIs = 0.07–1.18 and 0.08–5.28) were more likely to reduce early and late PTS compared with placebo; however, the treatment effects were not significant. Sensitivity analysis, after excluding a study enrolling only children, revealed that phenytoin had a significant effect in preventing early PTS (OR = 0.33; 95% CI = 0.14–0.78). Our findings indicate that no antiepileptic drug had an effect on early or late PTS superior to that of another; however, the sensitivity analysis revealed that phenytoin might prevent early PTS. Additional studies with large sample sizes and a rigorous design are required to obtain high-quality evidence on prophylactic anticonvulsant drug use in patients with traumatic brain injury.

Does Traumatic Brain Injury Cause Risky Substance Use or Substance Use Disorder?

There is a high co-occurrence of risky substance use among adults with traumatic brain injury (TBI), although it is unknown if the neurologic sequelae of TBI can promote this behavior. We propose that to conclude that TBI can cause risky substance use, it must be determined that TBI precedes risky substance use, that confounders with the potential to increase the likelihood of both TBI and risky substance use must be ruled out, and that there must be a plausible mechanism of action. In this review, we address these factors by providing an overview of key clinical and preclinical studies and list plausible mechanisms by which TBI could increase risky substance use. Human and animal studies have identified an association between TBI and risky substance use, although the strength of this association varies. Factors that may limit detection of this relationship include differential variability due to substance, sex, age of injury, and confounders that may influence the likelihood of both TBI and risky substance use. We propose possible mechanisms by which TBI could increase substance use that include damage-associated neuroplasticity, chronic changes in neuroimmune signaling, and TBI-associated alterations in brain networks.

Association of Head Injury With Late-Onset Epilepsy: Results From the Atherosclerosis Risk in Communities Cohort

BACKGROUND AND OBJECTIVES

Late-onset epilepsy (LOE; i.e., epilepsy starting in later adulthood) affects a significant number of individuals. Head injury is also a risk factor for acquired epilepsy, but the degree to which prior head injury may contribute to LOE is less well understood. Our objective was to determine the association between head injury and subsequent development of LOE.

METHODS

Included were 8,872 participants enrolled in the Atherosclerosis Risk in Communities (ARIC) study with continuous Centers for Medicare Services fee-for-service (FFS) coverage (55.1% women, 21.6% Black). We identified head injuries through 2018 from linked Medicare fee for service claims for inpatient/emergency department care, active surveillance of hospitalizations, and participant self-report. LOE cases through 2018 were identified from linked Medicare FFS claims. We used Cox proportional hazards models to evaluate associations of head injury with LOE, adjusting for demographic, cardiovascular, and lifestyle factors.

RESULTS

The adjusted hazard ratio (HR) for developing LOE after a history of head injury was 1.88 (95% confidence interval [CI] 1.44-2.43). There was evidence for dose-response associations with greater risk for LOE with increasing number of prior head injuries (HR 1.37, 95% CI 1.01-1.88 for 1 prior head injury and HR 3.55, 95% CI 2.51-5.02 for 2+ prior head injuries, compared to no head injuries) and with more severe head injury (HR 2.53, 95% CI 1.83-3.49 for mild injury and HR 4.90, 95% CI 3.15-7.64 for moderate/severe injury, compared to no head injuries). Associations with LOE were significant for head injuries sustained at older age (age ≥67 years: HR 4.01, 95% CI 2.91-5.54), but not for head injuries sustained at younger age (age < 67 years: HR 0.98, 95% CI 0.68-1.41).

DISCUSSION

Head injury was associated with increased risk of developing LOE, particularly when head injuries were sustained at an older age, and there was evidence for higher risk for LOE after a greater number of prior head injuries and after more severe head injuries.

CLASSIFICATION OF EVIDENCE

This study provides Class I evidence that an increased risk of late-onset epilepsy is associated with head injury and that this risk increases further with multiple and more severe head injuries.

Prophylactic Activation of Shh Signaling Attenuates TBI-Induced Seizures in Zebrafish by Modulating Glutamate Excitotoxicity through Eaat2a

Approximately 2 million individuals experience a traumatic brain injury (TBI) every year in the United States. Secondary injury begins within minutes after TBI, with alterations in cellular function and chemical signaling that contribute to excitotoxicity. Post-traumatic seizures (PTS) are experienced in an increasing number of TBI individuals that also display resistance to traditional anti-seizure medications (ASMs). Sonic hedgehog (Shh) is a signaling pathway that is upregulated following central nervous system damage in zebrafish and aids injury-induced regeneration. Using a modified Marmarou weight drop on adult zebrafish, we examined PTS following TBI and Shh modulation. We found that inhibiting Shh signaling by cyclopamine significantly increased PTS in TBI fish, prolonged the timeframe PTS was observed, and decreased survival across all TBI severities. Shh-inhibited TBI fish failed to respond to traditional ASMs, but were attenuated when treated with CNQX, which blocks ionotropic glutamate receptors. We found that the Smoothened agonist, purmorphamine, increased Eaat2a expression in undamaged brains compared to untreated controls, and purmorphamine treatment reduced glutamate excitotoxicity following TBI. Similarly, purmorphamine reduced PTS, edema, and cognitive deficits in TBI fish, while these pathologies were increased and/or prolonged in cyclopamine-treated TBI fish. However, the increased severity of TBI phenotypes with cyclopamine was reduced by cotreating fish with ceftriaxone, which induces Eaat2a expression. Collectively, these data suggest that Shh signaling induces Eaat2a expression and plays a role in regulating TBI-induced glutamate excitotoxicity and TBI sequelae.

Peripheral Infection after Traumatic Brain Injury Augments Excitability in the Perilesional Cortex and Dentate Gyrus

Peripheral infections occur in up to 28% of patients with traumatic brain injury (TBI), which is a major etiology for structural epilepsies. We hypothesized that infection occurring after TBI acts as a “second hit” and facilitates post-traumatic epileptogenesis. Adult male Sprague–Dawley rats were subjected to lateral fluid-percussion injury or sham-operation. At 8 weeks post-injury, rats were treated with lipopolysaccharide (LPS, 5 mg/kg) to mimic Gram-negative peripheral infection. T2-weighted magnetic resonance imaging was used to detect the cortical lesion type (small focal inflammatory [TBI_FI] vs. large cavity-forming [TBI_CF]). Spontaneous seizures were detected with video-electroencephalography, and seizure susceptibility was determined by the pentylenetetrazole (PTZ) test. Post-PTZ neuronal activation was assessed using c-Fos immunohistochemistry. LPS treatment increased the percentage of rats with PTZ-induced seizures among animals with TBI_FI lesions (p < 0.05). It also increased the cumulative duration of PTZ-induced seizures (p < 0.01), particularly in the TBI_FI group (p < 0.05). The number of c-Fos immunopositive cells was higher in the perilesional cortex of injured animals compared with sham-operated animals (p < 0.05), particularly in the TBI-LPS group (p < 0.05). LPS treatment increased the percentage of injured rats with bilateral c-Fos staining in the dentate gyrus (p < 0.05), particularly in the TBI_FI group (p < 0.05). Our findings demonstrate that peripheral infection after TBI increases PTZ-induced seizure susceptibility and neuronal activation in the perilesional cortex and bilaterally in the dentate gyrus, particularly in animals with prolonged perilesional T2 enhancement. Our data suggest that treatment of infections and reduction of post-injury neuro-inflammation are important components of the treatment regimen aiming at preventing epileptogenesis after TBI.

Role of Brain Natriuretic Peptide in the Prediction of Early Postoperative Seizures Following Surgery for Traumatic Acute Subdural Hematoma: A Prospective Study

INTRODUCTION

Brain natriuretic peptide (BNP) is a reliable biomarker in the acute phase of traumatic brain injury. However, the relationship between BNP and traumatic acute subdural hematoma (aSDH) has not yet been addressed. This study aimed to analyze BNP levels on admission in surgically treated patients and assess their relationship with early postoperative seizures (EPS) and functional outcomes.

METHODS

Patients with unilateral traumatic aSDH who were surgically treated in our department between July 2017 and May 2020 were included in the study. BNP was preoperatively measured. Patients' neurologic condition, radiographic variables on initial cranial computed tomography, sodium serum levels on admission, and occurrence of EPS were prospectively assessed. Functional outcome was assessed using the modified Rankin Scale (mRS) at discharge and follow-up (at 2-3 months). A poor outcome was defined by a mRS score > 3.

RESULTS

EPS occurred in 20 (19.6%) of 102 surgically treated patients in the final cohort on the median day 3. A significant association between EPS and a poor Glasgow Coma Scale score at the 7th postoperative day was found, which in turn independently predicted a poor functional outcome at discharge and follow-up. Nonetheless, EPS were not associated with poor functional outcomes. The multivariate analysis revealed BNP > 95.4 pg/ml (aOR = 5.7, p = 0.003), sodium < 137.5 mmol/l (aOR = 4.6, p = 0.009), and left-sided aSDH (aOR = 4.4, p = 0.020) as independent predictors of EPS.

CONCLUSION

In the early postoperative phase of traumatic aSDH, EPS were associated with worse neurologic conditions, which in turn independently predicted poor outcomes at discharge and follow-up. Although several EPS risk factors have already been elucidated, this study presents BNP as a novel reliable predictor of EPS. Further larger studies are needed to determine whether a more precise estimate of EPS risk using BNP levels can be reached.

Knowledge atlas of post-traumatic epilepsy research: Based on citespace visualization analysis

The mechanism of posttraumatic epilepsy (PTE) is complicated and the treatment and prognostic effects are not satisfactory. In this study, CiteSpace and VOSviewer are used to analyze the literature related to PTE (January 2000-June 2020). The aspects of the cooperative network (author, institution, and country), keywords co-occurrence, document co-citation clustering, and journal dual-map overlay were analyzed, and the atlas was constructed. The United States, Finland, and other research institutions have frequently published PTE-related articles, thus having richer research results. The relevant research was mostly published in journals, such as Journal of Neurotrauma, Journal of Neuroscience, Brain Research, Neurobiology of Disease. Quantitative diffusion MRI plays a critical role in PTE research. The study on the susceptibility to seizures and the underlying mechanism of PTE received different degrees of attention. The present study provided an in-depth understanding of the research foundation, relevant research results, the current research frontiers, and the main research focus in the PTE field. Herein, we briefly discussed relevant key articles and also provided ideas for future research directions.

Factors Affecting Outcomes in Geriatric Traumatic Subdural Hematoma in a Neurosurgical Intensive Care Unit

BACKGROUND AND OBJECTIVE

Geriatric patients (age ≥65 years) who sustain a traumatic brain injury have an increased risk of poor outcomes and higher mortality compared with younger cohorts. We aimed to evaluate the risk factors for discharge outcomes in a geriatric traumatic subdural hematoma population, stratified by age and pretraumatic medical comorbidities. This was a single-center retrospective cohort study of geriatric patients (N = 207).

METHODS

Patient charts were evaluated for factors including patient characteristics, comorbidities, injury-related and seizure-related factors, neurosurgical intervention, and patient disposition on discharge.

RESULTS

Bivariate and multivariate analyses showed that age was nonpredictive of patient outcomes. Underlying vasculopathic comorbidities were the primary determinant of posttraumatic seizure, surgical, and discharge outcomes. Multifactor analysis showed that patients who went on to develop status epilepticus (n = 11) had a higher frequency of vasculopathic comorbidities with strong predictive power in poor patient outcomes.

CONCLUSIONS

Our findings suggest a need to establish unique prognostic risk factors based on patient outcomes that guide medical and surgical treatment in geriatric patients.

Spatial and temporal profile of high-frequency oscillations in posttraumatic epileptogenesis

We studied the role of temporal and spatial changes in high-frequency oscillation (HFO, 80–500 Hz) generation in epileptogenesis following traumatic brain injury (TBI).

Experiments were conducted on adult male Sprague Dawley rats. For the TBI group, fluid percussion injury (FPI) on the left sensorimotor area was performed to induce posttraumatic epileptogenesis. For the sham control group, only the craniotomy was performed. After TBI, 8 bipolar micro-electrodes were implanted bilaterally in the prefrontal cortex, perilesional area and homotopic contralateral site, striatum, and hippocampus. Long-term video/local field potential (LFP) recordings were performed for up to 21 weeks to identify and characterize seizures and capture HFOs. The electrode tip locations and the volume of post TBI brain lesions were further estimated by ex-vivo MRI scans. HFOs were detected during slow-wave sleep and categorized as ripple (80–200 Hz) and fast ripple (FR, 250–500 Hz) events. HFO rates and the HFO peak frequencies were compared in the 8 recording locations and across 8-weeks following TBI.

Data from 48 rats (8 sham controls and 40 TBI rats) were analyzed. Within the TBI group, 22 rats (55%) developed recurrent spontaneous seizures (E+ group), at an average of 62.2 (+17.1) days, while 18 rats (45%) did not (E− group). We observed that the HFOs in the E+ group had a higher mean peak frequency than the E− group and the sham group (P < 0.05). Furthermore, the FR rate of the E+ group showed a significant increase compared to the E−group (P < 0.01) and sham control group (P < 0.01), specifically in the perilesional area, homotopic contralateral site, bilateral hippocampus, and to a lesser degree bilateral striatum. When compared across time, the increased FR rate in the E+ group occurred immediately after the insult and remained stable across the duration of the experiment. In addition, lesion size was not statistically different in the E+ and E− group and was not correlated with HFO rates.

Our results suggest that TBI results in the formation of a widespread epileptogenic network. FR rates serve as a biomarker of network formation and predict the future development of epilepsy, however FR are not a temporally specific biomarker of TBI sequelae responsible for epileptogenesis. These results suggest that in patients, future risk of post-TBI epilepsy can be predicted early using FR.

Incidence of post-traumatic epilepsy following paediatric traumatic brain injury: protocol for systematic review and meta-analysis

INTRODUCTION

Post-traumatic epilepsy (PTE) is a recognised complication of traumatic brain injury (TBI), and is associated with higher rates of mortality and morbidity when compared with patients with TBI who do not develop PTE. The majority of the literature on PTE has focused on adult populations, and consequently there is a paucity of information regarding paediatric cohorts. Additionally, there is considerable heterogeneity surrounding the reported incidence of PTE following childhood TBI in the current literature. The primary aim of our study is to summarise reported PTE incidences in paediatric populations to derive an accurate estimate of the global incidence of PTE following childhood TBI. Our secondary aim is to explore risk factors that increase the likelihood of developing PTE.

METHODS AND ANALYSIS

A systematic literature search of Embase (1947-2021), PubMed (1996-2021) and Web of Science (1900-2021) will be conducted. Publications in English that report the incidence of PTE in populations under 18 years of age will be included. Publications that evaluate fewer than 10 patients, report an alternative cause of epilepsy, or in which a paediatric cohort is not discernable, will be excluded. Independent investigators will identify the relevant publications, and discrepancies will be adjudicated by a third independent investigator. Data extracted will include incidence of PTE, time intervals between TBI and PTE, seizure characteristics, injury characteristics, patient demographics and clinical data. Data extraction will be performed by two independent investigators and cross-checked by a third investigator. A descriptive analysis of PTE incidence will be conducted and a weighted mean will be calculated. If sufficient data are available, stratified meta-analysis of subgroups will also be conducted.

ETHICS AND DISSEMINATION

Ethics approval was not required for this study. We intend to publish our findings in a high-quality peer-reviewed journal on completion.

PROSPERO REGISTRATION NUMBER

CRD42021245802.

Lesion Normalization and Supervised Learning in Post-traumatic Seizure Classification with Diffusion MRI

Traumatic brain injury (TBI) is a serious condition, potentially causing seizures and other lifelong disabilities. Patients who experience at least one seizure one week after TBI (late seizure) are at high risk for lifelong complications of TBI, such as post-traumatic epilepsy (PTE). Identifying which TBI patients are at risk of developing seizures remains a challenge. Although magnetic resonance imaging (MRI) methods that probe structural and functional alterations after TBI are promising for biomarker detection, physical deformations following moderate-severe TBI present problems for standard processing of neuroimaging data, complicating the search for biomarkers. In this work, we consider a prediction task to identify which TBI patients will develop late seizures, using fractional anisotropy (FA) features from white matter tracts in diffusion-weighted MRI (dMRI). To understand how best to account for brain lesions and deformations, four preprocessing strategies are applied to dMRI, including the novel application of a lesion normalization technique to dMRI. The pipeline involving the lesion normalization technique provides the best prediction performance, with a mean accuracy of 0.819 and a mean area under the curve of 0.785. Finally, following statistical analyses of selected features, we recommend the dMRI alterations of a certain white matter tract as a potential biomarker.

Risk of Developing Epilepsy after Autoimmune Encephalitis

BACKGROUND

Acute symptomatic seizures (ASS) are a common manifestation of autoimmune encephalitis (AE), but the risk of developing epilepsy as a sequela of AE remains unknown, and factors predisposing the development of epilepsy have not been fully identified.

OBJECTIVE

To assess the risk of developing epilepsy in AE and study related risk factors.

MATERIALS AND METHODS

This was a retrospective single centre study including patients diagnosed with AE according to criteria described by Graus et al., with a minimum follow-up of 12 months after AE resolution. The sample was divided according to whether patients developed epilepsy or not.

RESULTS

A total of 19 patients were included; 3 (15.8%) had AE with intracellular antibodies, 9 (47.4%) with extracellular antibodies, and 7 (36.8%) were seronegative. During follow-up, 3 patients (15.8%) died, 4 (21.1%) presented relapses of AE, and 11 (57.89%) developed epilepsy. There was a significant association between the development of epilepsy and the presence of hippocampal atrophy in control brain magnetic resonance imaging (MRI) (p = 0.037), interictal epileptiform discharges (IED) on control electroencephalogram (EEG) (p = 0.045), and immunotherapy delay (p = 0.016).

CONCLUSIONS

Hippocampal atrophy in neuroimaging, IED on EEG during follow-up, and immunotherapy delay could be predictors of the development of epilepsy in patients with AE.