Prevalence of periodic limb movement in sleep in people with epilepsy: A semi-structured literature review

Abstract

Objectives: Epilepsy is a prevalent health problem worldwide in all ages, and it is essential to identify disease markers for diagnosis and treatment. Periodic limb movements in sleep (PLMS) are a common finding in polysomnography (PSG). Still, its clinical relevance in people with epilepsy (PWE) is unknown. The aim of this review was to compare PLMS frequency in PWE and controls.

Methods: A semi-structured literature review was conducted using PubMed in search of relevant studies in English on August 23, 2019, with the search terms "sleep," "epilepsy," or "seizure," and "polysomnography" in the title and/or abstract. The research was complemented with citation analysis and manual search using Google Scholar. Studies involved PWE and comparative controls using PSG with reported PLMS index (PLMI).

Results: Seven studies were identified. Only two showed a statistically significant difference in PLMI between cases and controls, and in another study, cases had uncontrolled seizures. In general, studies did not adjust for potential confounders including demographics, apnea-hypopnea index, or medication use.

Conclusions: We found few studies exploring the prevalence of PLMS in PWE. In the majority, PLMI did not differ from controls. Further studies are warranted given the prevalence of sleep disturbances in epilepsy.

Keywords: Arousal; Epilepsy; Periodic limb movements in sleep (PLMS); Periodic limb movements index (PLMI); Polysomnography; Seizure.