Early Seizures Following Traumatic Brain Injury Tied to Poor Outcomes

Early posttraumatic seizures (EPS) following moderate to severe traumatic brain injury (TBI) are linked with higher risk of morbidity, mortality, and posttraumatic epilepsy (PTE), according to new research in JAMA Neurology.

Prior studies have indicated EPS during the acute phase of TBI are associated with increased morbidity and mortality, but the role of EPS and its treatment in PTE is unclear. Few studies have evaluated risk factors. In the current study, Australian researchers sought to identify EPS risk factors, evaluate the morbidity and mortality involved with EPS, and develop a risk assessment prediction model for EPS.

Australian trauma registry participants who had sustained a TBI between 2005 and 2019 and did not have preexisting epilepsy participated in the study. Researchers performed long-rank test and Wald test in Cox regression to screen potential risk factors for long-term mortality and assess the association between EPS and long-term mortality. They developed and tested a prediction model for EPS.

Of the 15,152 participants (69% men, median age 60 years), 416 were found to have EPS (27 with status epilepticus). At a 2-year assessment (75% reporting), patients who developed EPS were more likely to have become severely disabled or deceased. They were also more likely to have developed PTE (78% vs 19%, 15% reporting; P <.001) or taking antiseizure medication (68% vs 19% P <.001). Patients with EPS had a higher long-term mortality rate (24% vs 14%; P <.001).

Multivariable analysis showed patients with Charlson Comorbidity Index (CCI) score of 2 were nearly 4 times more likely to have EPS compared with patients who did not have CCI. Abbreviated Injury Scale (AIS) head severity score of 5 or 6, compared with AIS of 3, was associated with 3 times the risk of EPS.

Adjusting for confounders, the researchers found that patients who developed EPS in the hospital had increased risk of ICU admission, ventilation, longer time on ventilator in the intensive care unit (ICU), and longer stay in the hospital. They had higher risk of discharge to inpatient rehabilitation. The patients had more than 2 times the risk of becoming severely disabled or dying. They had increased risk of taking antiseizure medications (RR 2.44) and had nearly triple the risk of developing PTE in the first 2 years following injury. They were at increased risk of losing awareness (RR 3.97).

The algorithm indicated EPS is associated with isolated TBI, lower social status, higher medical comorbidity, cause of injury, and the injury severity indicators of AIS head, Injury Severity Score, and Glasgow Coma Scale (GCS) score. In addition, the presence of subdural hematoma or subarachnoid hemorrhage were identified as risk factors.

Preexisting CCI score, SDH, and AIS head severity score of 5 or 6 contributed most toward association with EPS. The model had an overall performance of area under the ROC of 0.72, with sensitivity of 66% and specificity of 73%.

Study limitations included observational study, missing data, lack of evaluation of association of EPS with other in-hospital risk factors of acute symptomatic seizures, self-report questionnaire, and possibility that patients may have included EPS in responses to seizures after injury.

“Early posttraumatic seizures are associated with significant in-hospital morbidity, poorer outcomes, and subsequent risk of mortality at 24 months on follow-up [Glasgow Outcome Scale–Extended] GOS-E,” the researchers concluded.

Disclosure: Some study authors declared affiliations with biotech, pharmaceutical, and/or device companies. Please see the original reference for a full list of authors’ disclosures. 

Reference

Laing J, Gabbe B, Chen Z, et al. Risk factors and prognosis of early posttraumatic seizures in moderate to severe traumatic brain injury. JAMA Neurol. Published online February 21, 2022. doi: 10.1001/jamaneurol.2021.5420