Early posttraumatic seizures linked to poor outcomes in moderate to severe TBI patients

Early posttraumatic seizures following moderate to severe TBI were linked to poorer in-hospital and long-term outcomes, including posttraumatic epilepsy, according to an Australian registry-based cohort study published in JAMA Neurology.

“The role of [early posttraumatic seizures (EPS)] in the subsequent development of recurrent unprovoked seizures, or posttraumatic epilepsy (PTE), is not well understood,” Joshua Laing, BBiomedSc, MBBS, of the department of neurosciences at Monash University, and colleagues wrote. “Early posttraumatic seizures may increase the risk of PTE. Whether treatment of EPS exerts an antiepileptogenic effect on developing PTE is largely unknown.”

Researchers evaluated risk factors for EPS and contribution to PTE, as well as associated morbidity and mortality, by collecting data from an Australian-based cohort of 15,152 adults (69% male, median age 60 years) diagnosed with moderate to severe TBI between January 2005 and December 2019, along with a 2-year follow-up.

They identified EPS via International Statistical Classification of Diseases, Tenth Revision, Australian Modification (ICD-10-AM) codes and measured several outcomes, including in-hospital metrics, 2-year outcomes including PTE and post-discharge mortality.

Results showed that 416 (2.7%) participants were identified with EPS, including 27 (0.2%) with status epilepticus. Among the significant risk factors for developing EPS were younger age, TBI sustained from a low fall, subdural and subarachnoid hemorrhage, and greater head injury severity, measured using the Abbreviated Injury Scale and Glasgow Coma Score.

After adjusting for confounders, researchers associated EPS with increased ICU admission and length of stay, ventilation and duration, length of hospital stay and discharge to rehabilitation facilities instead of home, but not in-hospital mortality. Outcomes in TBI admission survivors at the 2-year follow-up included mortality (RR=2.14; 95% CI, 1.32-3.46), development of PTE (RR=2.91; 95% CI, 2.22-3.81) and use of antiseizure medications (RR=2.44; 95% CI, 1.98-3.02), which were poorer for cases with EPS after adjustment for confounders.

“In this study of moderate to severe TBI inclusive of all seizures during the acute admission, just 11% of patients with EPS developed PTE, although this was significantly greater that the 3% incidence in those without EPS,” Laing and colleagues wrote.

In a related editorial, James J. Gugger, MD, PharmD, and Ramon Diaz-Arrastia, MD, PhD, from the department of neurology at University of Pennsylvania Perelman School of Medicine, noted that while Laing and colleagues’ findings were significant, statistics may be even more alarming for PTE development following EPS.

“The authors found that the probability of developing PTE after EPS was 11%,” Gugger and Diaz-Arrastia wrote. “Other studies using cEEG data have shown higher risk for PTE among those with EPS. In a recent study of 46 patients with 2-year follow-up after moderate to severe TBI, the probability of developing PTE among those with EPS was 38%.

“Despite its limitations, the study by Laing et al advances our understanding of EPS,” Gugger and Diaz-Arrastia continued. “They showed that EPS are more common among those with more severe injuries and preinjury medical comorbidities as well as those with subdural hemorrhage or subarachnoid hemorrhage. This study is also an important reminder to clinicians that EPS portend a poor outcome.”