Epileptiform activity in traumatic brain injury predicts post-traumatic epilepsy

Abstract

We hypothesize that epileptiform abnormalities (EAs) in the electroencephalogram (EEG) during the acute period following traumatic brain injury (TBI) independently predict first-year post-traumatic epilepsy (PTE₁ ). We analyze PTE₁ risk factors in two cohorts matched for TBI severity and age (n = 50). EAs independently predict risk for PTE₁ (odds ratio [OR], 3.16 [0.99, 11.68]); subdural hematoma is another independent risk factor (OR, 4.13 [1.18, 39.33]). Differences in EA rates are apparent within 5 days following TBI. Our results suggest that increased EA prevalence identifies patients at increased risk for PTE₁ , and that EAs acutely post-TBI can identify patients most likely to benefit from antiepileptogenesis drug trials. Ann Neurol 2018;83:858-862.

Figure 1

EEG recording distribution and prevalence in PTE₁ (red) and non-PTE₁ (blue) patients. A) EEG recording days (colored boxes) plotted for individual patients plotted along y-axis based on TBI severity. Shading based upon presence (dark) or absence (light) of EA during that day’s recording. B) Histogram summarizing the proportion of EEGs during each 5 day time-period. C) Prevalence of EA in PTE₁ and non-PTE₁ groups. D) Prevalence of EA subtypes in PTE₁ and non-PTE₁ groups. E) Cumulative probability of the first appearance EDs in recordings up to the first 10 days post-TBI. F) Models of possible causal relationship between SDH, EA and PTE₁. Model (1) with dotted box outline is the most likely model based upon logistic regression.