Sleep quality and daytime sleepiness in epilepsy: Systematic review and meta-analysis of 25 studies including 8,196 individuals

We sought to gain a better understanding of the relationship between epilepsy and sleep quality and daytime sleepiness by performing a literature search of PubMed for case–control studies that compared patients with epilepsy to controls and reported the Pittsburgh sleep quality index (PSQI) and/or the Epworth sleepiness scale (ESS). Study-specific mean differences in the PSQI and ESS between cases and controls were extracted from the publications and pooled using random-effects meta-analysis. Twenty-five studies (2964 cases, 5232 controls) were included. Fifteen studies reported the PSQI and 24 the ESS. Mean age was 40 years; 50.4% were women. When comparing cases to controls, the pooled mean differences in the PSQI and ESS were 1.27 (95% confidence interval (CI): 0.76, 1.78; P < 0.001; I2: 81.4%) and 0.38 (95% CI: −0.07, 0.84; P = 0.099; I2: 81.0%). Subgroup analyses revealed that mean differences in the ESS were significantly lower in studies with a higher proportion of patients with focal epilepsy (P = 0.004). In this large-scale meta-analysis patients with epilepsy had a higher PSQI, close to the pathological cut-off, compared to controls, but a similar and unremarkable ESS. Further studies are needed to investigate potential effect modifiers, such as specific antiepileptic drugs or seizure frequency.