Epilepsy and refractory epilepsy is less likely to be associated with stroke in older adult survivors and more likely to be associated with younger age and other factors, according to a recent study published in Neurology

Researchers designed a retrospective cohort study using population-based data from linked health records in Ontario, Canada, to investigate the occurrence of new-onset stroke-related epilepsy cases, and to determine factors associated with resulting epilepsy or refractory epilepsy. Using records from the Ontario Stroke Registry, researchers identified all stroke patients aged 67 years old or older who had been discharged from designated stroke centers between April 2003, and March 2009. Investigators reviewed records up to 2 years postdischarge in order to identify diagnoses of new-onset epilepsy. Researchers then noted diagnoses of refractory epilepsy, defined as continued seizures despite “2 adequate pharmacologic intervention trials within 18 months.”

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The study included 19,138 patients hospitalized for stroke: new-onset epilepsy was identified in 210 (1.1%) of these patients, 27 (12.9%) of whom were classified as having treatment refractory epilepsy. Researchers report signification significant association between development of epilepsy and younger age (mean age 77.40±6.48 years; P <.001), having higher scores on the Charlson Comorbidity Index (P <.001), having pneumonia (P <.001), depression and anxiety (P <.001), and atrial fibrillation (P <.001). Significant findings associated with patients having higher number of prescriptions (11.87±6.34; P <.001), more outpatient visits (40.48±25.55; P <.001), and more hospital admissions (3.02±2.18; P <.001) was also reported.

Using multivariable analysis, study researchers find age (hazard ratio [HR] 0.91; 95% CI, 0.89-0.93) and in-hospital thrombolysis (HR 1.73; 95% CI, 1.03-2.91) was significantly associated with the risk for developing epilepsy. Through bivariate analyses it significant associations were found between refractory epilepsy and  younger age of diagnosis (mean age 73.52±5.32 years; P <.001).

Limitations of this study included having a small sample size and low sensitivity algorithms used to identify patients with epilepsy. Researchers also report on-set epilepsy, depression, and data attributed to stroke may have been underestimated and, thus, limited these findings.

The investigators concluded that “aging may reduce risk of new-onset epilepsy and refractory epilepsy following stroke” and urged for “continued research of epilepsy that is cerebrovascular in etiology, particularly in study populations with narrow age ranges, [as they would] would further elucidate the prognostic value of the other variables studied here.”

Disclosure: One study author declared an affiliation with the pharmaceutical industry. Please see the original reference for a full list of authors’ disclosures.

Reference

Burneo JG, Antaya TC, Allen BN, Belisle A, Shariff SZ, Saposnik G. The risk of new-onset epilepsy and refractory epilepsy in older adult stroke survivors [published online July 10, 2019]. Neurology. doi: 10.1212/WNL.0000000000007895.