Sleep is often fragmented by epileptiform discharges and seizures in adult patients with developmental and epileptic encephalopathies, such as Lennox-Gastaut syndrome (LGS), found a new study published in the journal Epilepsy Open.

Obstructive sleep apnea was also present, which may increase the risk of cardiovascular disease and premature death, the study authors noted.

Read more about the symptoms of LGS

To assess sleep and respiratory abnormalities in adults with epileptic encephalopathies, and evaluate their relationship with seizures, a team of researchers led by Patrick Kwan, MB, PhD, from The University of Melbourne in Australia analyzed 13 patients, who were 20 to 50 years of age and who underwent concurrent polysomnography and inpatient video-EEG monitoring between December 2011 and July 2022. 

Of these 13 patients, 2 had LGS-like phenotype, and 6 had LGS. The remaining patients had Landau–Kleffner syndrome, epilepsy with myoclonic-atonic seizures, or epileptic encephalopathies and unclassified developmental.

The results showed that epileptiform discharges and seizures led to arousal during sleep (a median of 29 arousals per hour). More than half of the patients (53.8%) also had moderate-to-severe obstructive sleep apnea.

A total of 3 patients had tonic seizures that frequently occurred with central apnea. One of these was classified as mild central sleep apnea. Of these 3 patients, 2 experienced other identifiable seizures. However, in 1 patient, central apnea was the only seizure manifestation.

“Polysomnography during video-EEG is an effective diagnostic tool in detecting sleep and seizure-related respiratory abnormalities,” the researchers concluded. “Treatment of epilepsy may improve sleep quality, and conversely, improved sleep, may decrease seizure burden.”

LGS is a rare and severe type of childhood epileptic encephalopathy characterized by multiple types of seizures, including myoclonic, atypical absence, tonic, atonic, generalized tonic-clonic, and nonconvulsive status epilepticus seizures, specific brain wave patterns on electroencephalography, and cognitive impairment that usually continues through adolescence and into adulthood. 


Sivathamboo S, Myers KA, Pattichis A, et al. Sleep and respiratory abnormalities in adults with developmental and epileptic encephalopathies using polysomnography and video-EEG monitoring. Epilepsia Open. Published online June 5, 2023. doi:10.1002/epi4.12772