Antiseizure Medications May Improve Seizure Control in Post-Stroke Epilepsy

Antiseizure medications with slow activation of sodium channels may provide clinical benefits in post-stroke epilepsy.

Lacosamide and eslicarbazepine are both well-tolerated and may be associated with better seizure control in patients with post-stroke epilepsy, according to a multicenter observational study published in Seizure: European Journal of Epilepsy.

Post-stroke epilepsy, which has an incidence rate of about 7%, may account for up to half of all new epileptic seizures occurring in people aged 65 years and older. None of the available antiseizure medications (ASMs) are recommended for preventive epilepsy development following a stroke, however ASMs might be efficacious following a first unprovoked seizure in patients with high risk for recurrence. As of now, there are no recommendations for choice of anticonvulsants for post-stroke seizure treatment.

For the study, researchers sought to compare the efficacy of various antiseizure monotherapies in post-stroke epilepsy.

They used the Mainz Epilepsy Register (population-based register of patients with epilepsy treated in the Mainz Comprehensive Epilepsy and Sleep Medicine Center in Mainz, Germany) and the Marburg Stroke Register (population-based stroke register recruiting permanent residents in the district Marburg-Biedenkopf, Germany with acute ischemic stroke) to enroll 207 patients with post-stroke epilepsy who maintained initial antiseizure monotherapy for 12 months following the initiation of ASM. Efficacy was gauged according to a standardized 3-month seizure frequency and seizure freedom. Safety was estimated according to reports of side effects.

The researchers found the mean 3-month seizure frequency to be 1.9±3.1 on eslicarbazepine, 2.1±3.2 on lacosamide, 3.4±4.4 on levetiracetam, 4.3±6.8 on lamotrigine, and 5.1±7.3 on valproate (P <.05 for eslicarbazepine or lacosamide in comparison with levetiracetam, lamotrigine, and valproate, respectively).

They noted the greatest seizure freedom and the minimum seizure frequency on ASMs acting via the slow inactivation of sodium channels in comparison to other mechanisms of action (0.7±0.9 vs 2.2±2.4; P <.01). Most commonly reported side effects were vertigo (25.0%) and tiredness (15.9%) and side effects were similar in all ASM groups.

Multiple regression analysis revealed independent factors increasing seizure frequency to include hemorrhagic transformation, cortical involvement, increased size of infarction, neurological deficits at admission, and functional impairment. Analysis showed the independent factor decreasing seizure frequency to be administration of ASM with the mechanism of action via the slow inactivation of sodium channels.

Study limitations were acknowledged in the observational nature, selection bias towards more severe cases, non-evaluation of ASM in post-hemorrhagic epilepsy, and residual confounding by unmeasured variables.

“The new sodium channel blockers (lacosamide and eslicarbazepine) have showed to exert their major mechanism,” the researchers stated. “Given the theoretical benefit of sodium channel blockers in the treatment of post-stroke seizures and given the results of our observational study, which showed the clinical advantages of the ASMs with this mechanism of action[lacosamide and eslicarbazepine], future clinical studies are encouraged to investigate these ASMs in PSE in the setting of randomized clinical trials (RCT).”

Disclosure: This research was supported by UCB Pharma. Some study authors declared affiliations with biotech, pharmaceutical, and/or device companies. Please see the original reference for a full list of authors’ disclosures.

References:

Winter Y, Uphaus T, Sandner K, Klimpe S, Stuckrad-Barre SV, Groppa S. Efficacy and safety of antiseizure medication in post-stroke epilepsy. Seizure. Published online July 8, 2022. doi:10.1016/j.seizure.2022.07.003