Published May 15, 2024 NEUROLOGY Associations Between Nocturnal Hypoxia, Sleep Apnea, and Epilepsy By Staff The National Institutes of Health (NIH) recently released findings from a study exploring the association between sleep apnea and late-onset epilepsy. In the study, which was also published in the journal Sleep, the authors indicated that previous clinical data from small studies have demonstrated that sleep apnea is associated with unexplained onset of epilepsy in older adults.Employing data from the large, prospective Atherosclerosis Risk in Communities (ARIC) Study cohort, the researchers aimed to ascertain the correlation between sleep apnea and additional sleep characteristics and late-onset epilepsy (LOE), adjusting for comorbidities.The scientists reviewed and gathered data for LOE among ARIC participants by examining Medicare claims using polysomnography data from 1,309 ARIC participants who also participated in the Sleep Heart Health Study in 1995–1998, and demographic and comorbidity data from ARIC. Later, the risk of LOE was assessed utilizing survival analysis with a competing risk of death, and researchers also employed survival analysis in 2,672 ARIC participants to detect the correlation between self-reported obstructive sleep apnea (2011–2013) and the risk of subsequent LOE.The results revealed that late-midlife oxygen desaturation to less than 80%, which is defined as nocturnal hypoxia during sleep, was associated with subsequent development of LOE, adjusted subhazard ratio 3.28 (1.18-9.08); however, the apnea-hypopnea index was not related. Moreover, the participants’ report of sleep apnea diagnosis in 2011–2013 was also related to subsequent LOE, adjusted subhazard ratio 2.59 (1.24-5.39).The authors concluded that LOE was associated with sleep apnea and oxygen saturation nadir during sleep, independently of hypertension and other comorbidities. Additionally, these findings may assist clinicians in better understanding the complex correlation between sleep disorders and LOE, as well as lead to the development of possible targets for novel therapies.Rebecca Gottesman, MD, PhD, chief of the Stroke Branch at the NIH’s National Institute of Neurological Disorders and Stroke (NINDS), and an author of the study stated, “There’s increasing evidence that late-onset epilepsy may be indicative of underlying vascular disease, or neurodegenerative disease, even potentially as a preclinical marker of neurodegenerative disease. Compared to other age groups, older adults have the highest incidence of new cases of epilepsy—up to half of which have no clear cause. Sleep apnea is common among people with epilepsy, but the association is not well understood.”Lead researcher Christopher Carosella, MD, assistant professor of neurology at Johns Hopkins University, indicated, “Discovering a reversible cause for the development of any type of idiopathic epilepsy is an aspirational goal for epilepsy researchers or clinicians. We hope this study might be a small first step in that direction and also an encouragement to evaluate and treat sleep disorders in patients with epilepsy.”The NIH researchers indicated that “Because sleep apnea can have cardiovascular and brain health-related effects, the findings may also ultimately help to identify individuals at risk for some of these other conditions, providing a potential opportunity for treatment and prevention.”Lastly, the authors also stated that additional studies are necessary to evaluate whether treating sleep apnea in patients at risk for LOE may help avert the manifestation of this condition. The content contained in this article is for informational purposes only. The content is not intended to be a substitute for professional advice. Reliance on any information provided in this article is solely at your own risk.