Introduction: Seizure is a known complication of severe TBI (sTBI), and prophylaxis is recommended. 1st line at our institution is levetiracetam (LEV): 60 mg/kg load (max 3 gm), then 20 mg/kg IV q12hr x 7 days. In 2018, continuous EEG (cEEG) monitoring was incorporated into our institution’s standard sTBI management. Here, we examine the incidence of subclinical seizure captured on cEEG and hypothesize that subclinical seizure is common despite LEV seizure prophylaxis.
Methods: 7-year (01/2018-12/2024) retrospective study of children aged 1.5-18 years admitted to our PICU with sTBI and receiving cEEG monitoring. Subclinical seizure occurring within the 1st 12-hrs after cEEG leads placement was recorded. Patient demographics, clinical seizure, GCS score, injury severity score (ISS), cardiac arrest, neurosurgical intervention, and mortality data were also collected. Non-parametric statistical analyses were performed. A significant association between subclinical seizure and mortality was analyzed by Fisher Exact test.
Results: 54 patients were initially studied. 12 (22%) had suspected clinical seizure, and among these, 2 (17%) developed subclinical seizure despite treatment dosing of LEV. Among the 42 patients without clinical seizure, median [IQR] age: 11.2 [5.2-15.3] years, initial GCS score: 3 [3-6], and ISS: 29 [18-35]. 25 (60%) were male; 29 (69%) were white, 7 (17%) were black, and 6 (14%) were other race; 8 (19%) had cardiac arrest; 23 (55%) received neurosurgical intervention; and 11 (26%) died. 8 (19%) patients developed subclinical seizure despite LEV prophylaxis. Development of subclinical seizure was not associated with age, sex, race, GCS, ISS, cardiac arrest, or neurosurgical intervention. However, it was associated with increased mortality (OR: 17.4 [95%CI: 2.71-111.84], p< 0.001).
Conclusions: Development of subclinical seizure was common (19%) among our cohort of sTBI children despite LEV seizure prophylaxis and was associated with increased mortality. Our observation supports routine use of cEEG monitoring after sTBI, although the ideal duration of monitoring, and optimal early post-traumatic seizure prophylaxis strategies remain unknown. Further study is needed to determine whether early recognition and treatment of subclinical seizures improve patient outcome.
