Obstructive sleep apnea in people with epilepsy: Modifying risk.

Obstructive sleep apnea (OSA) is a common but underdiagnosed and undertreated sleep disorder among people with epilepsy (PWE). In PWE, this sleep disorder is often managed as a comorbid condition rather than a contributor to epilepsy outcomes. For many years, OSA has been associated with higher seizure burden and interictal epileptiform discharges. Emerging evidence links OSA to late onset epilepsy (LOE) and increased risk markers for sudden unexpected death in epilepsy (SUDEP). This evidence also suggests that treating OSA with continuous positive airway pressure may improve seizure control. This critical review of the literature posits that OSA should be viewed as a modifiable risk factor for PWE. We apply the Bradford Hill criteria for causation as a framework to appraise the evidence connecting OSA with (1) seizure severity, (2) incident LOE, and (3) SUDEP risk. OSA supports eight of nine Bradford Hill criteria to varying degrees: strength, consistency, temporality, biological gradient, plausibility, coherence, analogy, and experiment, but not specificity. Key limitations include confounding, selection and adherence biases, and limited randomized evidence. However, the evidence supports integrating systematic OSA screening and evidence-based treatment into epilepsy care. Future research should prioritize randomized trials to assess the impact of OSA treatment on epilepsy incidence, severity, and SUDEP risk.