Towards a clinically informed, data‐driven definition of elderly onset epilepsy

Abstract

SUMMARYObjective: Elderly onset epilepsy represents a distinct subpopulation that has received considerable attention due to the unique features of the disease in this age group. Research into this particular patient group has been limited by a lack of a standardized definition and understanding of the attributes associated with elderly onset epilepsy. Methods: We used a prospective cohort database to examine differences in patients stratified according to age of onset. Linear support vector machine learning incorporating all significant variables was used to predict age of onset according to prespecified thresholds. Sensitivity and specificity were calculated and plotted in receiveroperating characteristic (ROC) space. Feature coefficients achieving an absolute value of 0.25 or greater were graphed by age of onset to define how they vary with time. Results: We identified 2,449 patients, of whom 149 (6%) had an age of seizure onset of 65 or older. Fourteen clinical variables had an absolute predictive value of at least 0.25 at some point over the age of epilepsy-onset spectrum. Area under the curve in ROC space was maximized between ages of onset of 65 and 70. Features identified through machine learning were frequently threshold specific and were similar, but not identical, to those revealed through simple univariable and multivariable comparisons. Significance: This study provides an empirical, clinically informed definition of "elderly onset epilepsy." If validated, an age threshold of 65-70 years can be used for future studies of elderly onset epilepsy and permits targeted interventions according to the patient's age of onset.

The medical treatment of epilepsy in the elderly: A systematic review and meta‐analysis

“…We only included studies presenting data specific to elderly individuals. We initially defined elderly as individuals aged at least 65 years as per recent literature but modified our definition to those aged at least 60 years after having identified several studies that used this younger age limit, which is also consistent with the United Nations definition of the elderly . We excluded trials where >20% of individuals were younger than 60 years, unless there were sufficient data regarding individuals older than 60 years to be analyzed separately as a subgroup.…”

Late-onset epilepsy predicts stroke: Systematic review and meta-analysis

“…LOE emerges from the literature as a distinct phenotype of epilepsy. Josephson et al [9]identified key characteristics of LOE, including an absence of learning disorders or mental health issues, higher prevalence of focal seizures, and a lower prevalence of generalised tonic-clonic seizures. Although this phenotype is more common with increasing age, it first emerges in the 30s, with an increasing prevalence in the 40s and peak incidence in 60s and 70s [9].…”

“…Josephson et al [9]identified key characteristics of LOE, including an absence of learning disorders or mental health issues, higher prevalence of focal seizures, and a lower prevalence of generalised tonic-clonic seizures. Although this phenotype is more common with increasing age, it first emerges in the 30s, with an increasing prevalence in the 40s and peak incidence in 60s and 70s [9]. Furthermore, there is evidence that LOE associated J Wall with white matter lesions (WMLs) more frequently exhibits a phenotype of temporal lobe onset; whereas post-stroke seizures are more commonly associated with a frontal lobe focus [10].…”

Outcomes of status epilepticus and their predictors in the elderly—A systematic review

“…Age is more than just a chronological number and encompasses physiological changes, comorbidities and frailty among other measure. However, we note that an accepted age cut-off for the elderly is required to standardize epilepsy research findings [93].…”