Pharmacological treatments for preventing epilepsy following traumatic head injury

Head injury is a common event and can cause a spectrum of motor and cognition disabilities. A frequent complication is seizures. Antiepileptic drugs (AED) such as phenytoin are often used in clinical practice with the hopes of preventing post-traumatic epilepsy. Whether immediate medical intervention following head trauma with either AEDs or neuroprotective drugs can alter the process of epileptogenesis and lead to a more favorable outcome is currently unknown. This review attempted to address the effectiveness of these treatment interventions. This review updates and expands on the earlier Cochrane review.

To compare the efficacy of antiepileptic drugs and neuroprotective agents with placebo, usual care or other pharmacologic agents for the prevention of post-traumatic epilepsy in people diagnosed with any severity of traumatic brain injury.

We searched The Cochrane Epilepsy Group's specialized register, CENTRAL, MEDLINE, ClinicalTrials.gov and World Health Organization International Clinical Trials Registry Platform (ICTRP) in January 2015. We searched EMBASE, Biological Abstracts and National Research Register in September 2014 and SCOPUS in December 2013. The Cochrane Epilepsy Group performed handsearches of relevant journals.

We included randomized controlled trials (RCTs) that include AEDs or neuroprotective agents compared with placebo, another pharmacologic agent or a usual care group. The outcomes measured included a seizure occurring within one week of trauma (early seizure), seizure occurring later than one week post-trauma (late seizure), mortality and any adverse events.

Two review authors independently assessed study quality and extracted the data. We calculated risk ratios (RR) and 95% confidence intervals (CI) for each outcome. We used random-effects models in the meta-analyses and performed pre-defined subgroup and sensitivity analyses.

This review included 10 RCTs (reported in 12 articles) consisting of 2326 participants The methodological quality of the studies varied. The type of intervention was separated into three categories; AED versus placebo or standard care, alternative neuroprotective agent versus placebo or standard care and AED versus other AED. Treatment with an AED (phenytoin or carbamazepine) decreased the risk of early seizure compared with placebo or standard care (RR 0.42, 95% CI 0.23 to 0.73; very low quality evidence). There was no evidence of a difference in the risk of late seizure occurrence between AEDs and placebo or standard care (RR 0.91, 95% CI 0.57 to 1.46; very low quality evidence). There was no evidence of a significant difference in all-cause mortality between AEDs and placebo or standard care (RR 1.08 95% CI 0.79 to 1.46,very low quality of evidence). Only one study looked at other potentially neuroprotective agents (magnesium sulfate) compared with placebo. The risk ratios were: late seizure 1.07 (95% CI 0.53 to 2.17) and all-cause mortality 1.20 (95% CI 0.80 to 1.81). The risk ratio for occurrence of early seizure was not estimable.Two studies looked at comparison of two AEDs (levetiracetam, valproate) with phenytoin used as the main comparator in each study. The risk ratio for all-cause mortality was 0.53 (95% CI 0.30 to 0.94). There was no evidence of treatment benefit of phenytoin compared with another AED for early seizures (RR 0.66, 95% 0.20 to 2.12) or late seizures(RR 0.77, 95% CI 0.46 to 1.30).Only two studies reported adverse events. The RR of any adverse event with AED compared with placebo was 1.65 (95% CI 0.73 to 3.66; low quality evidence). There were insufficient data on adverse events in the other treatment comparisons.

This review found low-quality evidence that early treatment with an AED compared with placebo or standard care reduced the risk of early post-traumatic seizures. There was no evidence to support a reduction in the risk of late seizures or mortality. There was insufficient evidence to make any conclusions regarding the effectiveness or safety of other neuroprotective agents compared with placebo or for the comparison of phenytoin, a traditional AED, with another AED.