Poststroke Seizures Linked to Increased Mortality, Severe Disability

Results of a new study suggest that poststroke seizures (PSSs) may be associated with significantly increased mortality and severe disability among patients with a history of stroke.

The study aimed to better understand outcomes in people who experience PSS compared with people without PSS by measuring mortality, poor functional outcome (modified Rankin scale [mRS] score 3-6), disability (mean mRS score), recurrent stoke, and dementia at the time of follow-up.

This systemic review and meta-analysis was published in JAMA Neurology.

Epilepsy awareness concept. Brain and encephalography in epilepsy patient during seizure attack, 3D illustration in purple color. Generative AI | Image credit: Ahmed - stock.adobe.com

“Previous studies have indicated that epileptic seizures adversely affect the functional, neurologic, and cognitive outcomes of patients with stroke,” wrote the researchers. “However, the published data are inconsistent and have not, to our knowledge, been systematically evaluated.”

The researchers searched databases for eligible studies from 1951 up until January 30, 2023, including MEDLINE, Embase, PsycInfo, Cochrane, and others. Studies included patients 18 years and older with a history of stroke, presenting with either early or late PSS. Studies of patients with a prior history of seizures before the index stroke were excluded. Additionally, a subgroup analysis was performed to examine the outcomes in patients with ischemic and hemorrhagic strokes separately.

In total, 71 studies were included in the analysis, including 1 bidirectional, 20 prospective, 47 retrospective, and 3 case-control studies. Furthermore, all studies were published in English and included patients from 31 countries.

The studies included 20,110 patients with PSS and 1,166,085 patients without PSS. Of these patients with PSS, 1967 (9.8%) had early seizures, 10,605 (52.7%) had late seizures after stroke, and 7538 (37.5%) had seizures that were not defined as either early or late. PSS was defined according to clinical or medical chart data in 59 studies using International Statistical Classification of Diseases, Tenth Revision codes in 12 studies.

Furthermore, PSSs were associated with increased mortality risk (odds ratio [OR], 2.1; 95% CI, 1.8-2.4), poor functional outcome (OR, 2.2; 95% CI, 1.8-2.8), greater disability (SMD, 0.6; 95% CI, 0.4-0.7), and increased dementia risk (OR, 3.1; 95% CI, 1.3-7.7) compared with no PSS.

In the subgroup analyses, early seizures were associated with mortality (OR, 2.4; 95% CI, 1.9-2.9) but late seizures were not (OR, 1.2; 95% CI, 0.8-2.0), and both ischemic (OR, 2.2; 95% CI, 1.8-2.7) and hemorrhagic stroke (OR, 1.4; 95% CI, 1.0-1.8) were associated with mortality.

Additionally, early (OR, 2.4; 95% CI, 1.6-3.4) and late seizures (OR, 2.7; 95% CI, 1.8-4.1) and ischemic (OR, 2.6; 95% CI, 1.9-3.7) and hemorrhagic stroke (OR, 1.9; 95% CI, 1.0-3.6) were associated with poor outcomes.

However, the researchers acknowledged some limitations to the study, including having little data from prospective studies, few studies having outcome data categorized by seizure or stroke subtype, and not having enough data to evaluate the effect of stroke severity on outcomes after PSS, which the researchers believe could have been a likely confounder.

Despite these limitations, the researchers believe the study shows that PSSs are associated with a doubled risk of death and severe disability. Furthermore, the researchers identified significant variability in the reporting standards across these studies and suggest how collaborative efforts and future research should work to address these challenges.

“Unraveling these associations is a high clinical and research priority,” wrote the researchers. “Trials of interventions to prevent seizures may be warranted.”

Reference

Misra S, Kasner SE, Dawson J, et al. Outcomes in patients with poststroke seizures. JAMA Neurology. Published online September 18, 2023. doi:10.1001/jamaneurol.2023.3240