medwireNews: Patients with a history of stroke have a significantly increased risk for mortality, poor functional outcomes, and severe disability if they have poststroke seizures (PSS), a systematic review and meta-analysis shows.
“The findings highlight that PSSs are a public health concern and warrant significant research efforts to prevent poststroke epileptogenesis,” say the researchers in JAMA Neurology.
Nishant Mishra (Yale University, New Haven, Connecticut, USA) and colleagues analyzed 71 observational, mainly retrospective (66%), studies that were carried out between 1951 and 2023 to compare outcomes for 20,110 stroke patients with PSS and 1,166,085 without PSS. Follow-up ranged from hospital discharge to 26 years.
“We suggest that within-study comparisons should be valid if follow- up was the same for patients with and without PSS, but absolute values are not readily interpretable,” say the researchers.
Among the individuals with PSS, 9.8% had early seizures (≤24 hours to ≤2 weeks) and 52.7% had late seizures (≥24 hours to ≥2 weeks), while in 37.5% of cases they were not classified. The participants were 18 years of age or older and had a history of either ischemic or hemorrhagic stroke or both.
Mishra et al assessed publication bias, adjusted for small-study effects, explored heterogeneity, and carried out outlier and sensitivity analyses to account for bias and confounding factors. Their analysis pooled odds ratios (ORs) and standardized mean difference (SMDs) for each of the five main study outcomes: mortality, poor functional outcome (modified Rankin scale [mRS] score of 3–6), disability (mean mRS score), recurrent stroke, and dementia.
The team found that patients with PSS had more than double the risk for both death and poor functional outcomes, compared with non-PSS patients (OR=2.1 across 57 studies and 2.2 across 22 studies, respectively).
In addition, patients with PSS had a significantly higher mean disability mRS at follow-up than their non-PSS counterparts, with a SMD of 0.6 across 10 studies.
In two studies, the team identified patients with PSS had a threefold increase in the risk for dementia compared with patients without PSS (OR=3.1). However, no association was found between PSS recurrent stroke across five studies.
Mishra et al also conducted subgroup analyses to compare outcomes according to the timing of seizures and the stroke subtypes. Patients with early- but not late-onset seizures had a significantly increased risk for mortality compared with those without seizures (OR=2.4 and 1.2, respectively), as did those with seizures following ischemic or hemorrhagic strokes (OR=2.2 and 1.4, respectively).
Patients with PSS irrespective of whether their seizures were early or late were significantly more likely than those without seizures to have poor functional outcome (OR =2.4 and 2.7, respectively), as were individuals with seizures following ischemic strokes (OR=2.6) but not those with PSS after hemorrhagic strokes (OR=1.9).
Mishra and colleagues say the results suggest that “PSS prevention is a high clinical and research priority.”
They caution, however, that inconsistent reporting of National Institutes of Health Stroke Scale data meant they were unable to examine the effect of stroke severity on clinical outcomes after PSS, “which is very likely a potential confounder,” and they could not determine the effects of concurrent medications with the data available.
The researchers comment that the “significant variation in reporting standards,” they found in their analysis should be addressed by collaborative scientific efforts.
medwireNews is an independent medical news service provided by Springer Healthcare Ltd. © 2023 Springer Healthcare Ltd, part of the Springer Nature Group