Cognitive Side Effects of Antiseizure Medications in Adults with Epilepsy

What was studied

This narrative review examined published research on how antiseizure medications may affect cognitive abilities, mostly in adults with epilepsy. The authors searched PubMed for studies published from January 2009 through December 2025 and considered evidence from randomized controlled trials, observational studies, meta-analyses, and systematic reviews.

The review focused on medications introduced into clinical practice since a prior 2009 review. It considered effects on attention, processing speed, memory, language, and executive function, as well as vulnerability among older adults and people with intellectual disabilities.

What they found

Newer medications—including rufinamide, lacosamide, brivaracetam, cannabidiol, fenfluramine, and ganaxolone—generally showed favorable cognitive profiles at recommended doses, particularly when used alone or in carefully selected combinations. Eslicarbazepine and cenobamate may be associated with mild, dose-dependent cognitive effects at the upper end of their recommended dose ranges.

Older medications and certain second-generation drugs, particularly topiramate and zonisamide, were consistently associated with higher cognitive risks. Older adults and people with intellectual disabilities may be especially vulnerable. The review emphasizes that cognitive difficulties in epilepsy are multifactorial, reflecting disease-related mechanisms, treatment effects, and their interaction.

Limits of the evidence

This was a narrative review rather than a single clinical trial. The abstract does not report the number of studies or participants, nor does it provide numerical estimates of how often cognitive effects occurred or how large they were for each medication. The evidence came from several types of studies, and the abstract does not provide enough detail to assess or directly compare their methods and findings.

For families and caregivers

Cognitive side effects may add to the day-to-day and psychosocial burden of epilepsy. The review supports balancing seizure control with cognitive preservation through individualized medication selection, cautious dose adjustment, and minimizing the use of multiple medications when appropriate. Cognitive problems should not automatically be attributed to medication because epilepsy-related mechanisms may also contribute.

What to watch next

The abstract does not identify specific priorities for future research. It also does not provide drug-by-drug numerical comparisons of cognitive risks, particularly for vulnerable groups.

Terms in this summary

antiseizure medication

A medicine used to prevent or reduce seizures.

cognitive function

Mental abilities such as attention, memory, language, planning, and speed of thinking.

executive function

Skills used to plan, organize, solve problems, and control behavior.

monotherapy

Treatment with one antiseizure medication.

polytherapy

Treatment with more than one antiseizure medication at the same time.

dose-dependent

An effect that may become more likely or stronger as the medication dose increases.

cautious titration

Adjusting a medication dose gradually while monitoring its effects.

narrative review

A broad synthesis and interpretation of previously published research.