Incidence and risk factors of posttraumatic seizures following traumatic brain injury: A Traumatic Brain Injury Model Systems Study

<jats:title>Summary</jats:title><jats:sec><jats:title>Objective</jats:title><jats:p>Determine incidence of posttraumatic seizure (<jats:styled-content style="fixed-case">PTS</jats:styled-content>) following traumatic brain injury (<jats:styled-content style="fixed-case">TBI</jats:styled-content>) among individuals with moderate‐to‐severe <jats:styled-content style="fixed-case">TBI</jats:styled-content> requiring rehabilitation and surviving at least 5 years.</jats:p></jats:sec><jats:sec><jats:title>Methods</jats:title><jats:p>Using the prospective <jats:styled-content style="fixed-case">TBI</jats:styled-content> Model Systems National Database, we calculated <jats:styled-content style="fixed-case">PTS</jats:styled-content> incidence during acute hospitalization, and at years 1, 2, and 5 postinjury in a continuously followed cohort enrolled from 1989 to 2000 (n = 795). Incidence rates were stratified by risk factors, and adjusted relative risk (<jats:styled-content style="fixed-case">RR</jats:styled-content>) was calculated. Late <jats:styled-content style="fixed-case">PTS</jats:styled-content> associations with immediate (<24 h), early (24 h–7 day), or late seizures (>7 day) versus no seizure prior to discharge from acute hospitalization was also examined.</jats:p></jats:sec><jats:sec><jats:title>Results</jats:title><jats:p><jats:styled-content style="fixed-case">PTS</jats:styled-content> incidence during acute hospitalization was highest immediately (<24 h) post‐<jats:styled-content style="fixed-case">TBI</jats:styled-content> (8.9%). New onset <jats:styled-content style="fixed-case">PTS</jats:styled-content> incidence was greatest between discharge from inpatient rehabilitation and year 1 (9.2%). Late <jats:styled-content style="fixed-case">PTS</jats:styled-content> cumulative incidence from injury to year 1 was 11.9%, and reached 20.5% by year 5. Immediate/early <jats:styled-content style="fixed-case">PTS RR</jats:styled-content> (2.04) was increased for those undergoing surgical evacuation procedures. Late <jats:styled-content style="fixed-case">PTS RR</jats:styled-content> was significantly greater for individuals who self‐identified as a race other than black/white (year 1 <jats:styled-content style="fixed-case">RR</jats:styled-content> = 2.22), and for black individuals (year 5 <jats:styled-content style="fixed-case">RR</jats:styled-content> = 3.02) versus white individuals. Late <jats:styled-content style="fixed-case">PTS</jats:styled-content> was greater for individuals with subarachnoid hemorrhage (year 1 <jats:styled-content style="fixed-case">RR</jats:styled-content> = 2.06) and individuals age 23–32 (year 5 <jats:styled-content style="fixed-case">RR</jats:styled-content> = 2.43) and 33–44 (year 5 <jats:styled-content style="fixed-case">RR</jats:styled-content> = 3.02). Late <jats:styled-content style="fixed-case">PTS RR</jats:styled-content> years 1 and 5 was significantly higher for those undergoing surgical evacuation procedures (<jats:styled-content style="fixed-case">RR</jats:styled-content>: 3.05 and 2.72, respectively).</jats:p></jats:sec><jats:sec><jats:title>Significance</jats:title><jats:p>In this prospective, longitudinal, observational study, <jats:styled-content style="fixed-case">PTS</jats:styled-content> incidence was similar to that in studies published previously. Individuals with immediate/late seizures during acute hospitalization have increased late <jats:styled-content style="fixed-case">PTS</jats:styled-content> risk. Race, intracranial pathologies, and neurosurgical procedures also influenced <jats:styled-content style="fixed-case">PTS RR</jats:styled-content>. Further studies are needed to examine the impact of seizure prophylaxis in high‐risk subgroups and to delineate contributors to race/age associations on long‐term seizure outcomes.</jats:p></jats:sec>