Chronic ASM Use Associated With Acute Symptomatic Seizures in Patients With Stroke

Data from a retrospective, single-center cohort study of 465 adults who underwent continuous EEG monitoring for acute symptomatic seizures (ASyS) suggests that chronic antiseizure medication (ASM) use of more than 6 months is associated with nonconvulsive ASyS.¹ Data guiding the duration ASM use in this population have been lacking to this point.

“Chronic ASM use is highly associated with electrographic, rather than convulsive, ASyS, with these patients 9 times more likely to be continued on chronic ASMs,” study author MarieElena Byrnes, DO, a neurology resident at Cleveland Clinic Neurological Institute, and colleagues, wrote. “With the ubiquity of stroke-related ASyS concerns in routine clinical practice, comparative effectiveness studies to guide ASM management are needed.”

Byrnes et al presented the date in a poster at the 2022 American Epilepsy Society Annual Meeting, held December 2 to 6, in Nashville, Tennessee. All told, their assessment utilized logistic regression and Cox regression multivariable modeling to assess the predictors of chronic and long-term ASM use, respectively. “Previously, we found that a majority of [patients with stroke] discharged on ASMs continue them beyond their first poststroke clinic visit,” they wrote.

­­Among the 179 patients who were discharged on ASMs, 73.7% (n = 132; 28.4% of total cohort) were still taking ASMs after 6 months, with 90.2.% (n = 119) not developing poststroke epilepsy. Poststroke epilepsy was reported in 4.3% (n = 2) of those on ASMs longer than 6 months (n = 47), and 9.1% (n = 12) of those on ASMs for 6 months or less (n = 132), for an odds ratio (OR) of 2.25 (95% CI, 0.58-14.82; P = 0.3). At the final follow-up (median, 61 months), 21.7% (n = 101) of the total cohort were on ASMs, and 14.4% (n = 67) developed poststroke epilepsy.

On univariable analysis of the characteristics associated with chronic ASM continuation among those discharged on ASMs, women had an adjusted OR of 2.2 (95% CI, 1.02-4.82), which was deemed significant (P = .045). Similarly, electrographic ASyS was associated with an OR of 9.27 (95% CI, 2.53-60.4), which was also significant (P = .004). Electrographic ASyS occurred in 4.3% (n = 2) of those on ASMs longer than 6 months, and 27.3% (n = 36) of those on ASMs 6 months or less, for an OR of 8.44 (95% CI, 2.43-53.34; P = .0004)

Admission duration (OR, 1.05; 95% CI, 1.00-1.11; P = .05) and stroke type—including ischemic stroke (reference), intracranial hemorrhage stroke type (OR, 1.63; 95% CI, 0.7-3.8; P = .25), and subarachnoid hemorrhage (OR, 0.36; 95% CI, 0.12-1.00) were also evaluated but were not significant. Admission duration lasted a median of 11 days (IQR, 5-18) for the overall cohort, lasting 7 days (IQR, 4-15.5) and 11 days (IQR, 6-19) for the cohorts on ASMs longer than 6 months and 6 months or less, respectively.