People with generalized epilepsy who have seizures from both side of the brain simultaneously have a higher risk of obstructive sleep apnea (OSA) compared with patients with focal epilepsy, according to new research published in Epilepsy & Behavior

Approximately 22 million Americans suffer from sleep apnea, with 80% of moderate to severe cases of OSA going undiagnosed. Additionally, more than 3 million Americans live with epilepsy, with approximately two-thirds of patients being able to keep their seizures under control with medication. Sleep apnea can be treated in a variety of ways, including using continuous positive airway pressure, wearing an oral appliance to keep the throat open while asleep, and weight loss. 

Investigators examined 115 patients from a level 4 epilepsy center to understand the relationship between epilepsy and OSA. Of these patients, 27 had generalized epilepsy and 88 had focal epilepsy, meaning that seizures only emanate from 1 side of the brain. 

According to the study, patients with epilepsy who were older, had a higher body-mass index, and a history of high blood pressure were at a greater risk of OSA. Additionally, no significant difference in excessive daytime sleepiness, which is a common symptom for people living with OSA, was found between the 2 types of epilepsy studied. 

"Possible reasons for higher risk of OSA in people with generalized epilepsy include greater brainstem dysfunction, altered control of the muscles of the upper airway, instability in the respiratory control system and differences in the anatomy of the upper airway," said lead author Matthew Scharf, MD, an assistant professor of medicine and neurology at Rutgers Robert Wood Johnson Medical School, in a prepared statement.

Medication usage may also be an answer, according to the study. Although medication use between the 2 groups was similar, patients with generalized epilepsy may have started these medications at a younger age and have used them longer. 

REFERENCE
Obstructive sleep apnea risk varies in patients with different types of epilepsy [news release] September 29, 2020; New Brunswick, NJ. Accessed November 12, 2020. https://www.eurekalert.org/pub_releases/2020-09/ru-osa092920.php