In recent years, numerous studies have explored the important and complex relationship between epilepsy and sleep. A review published in Epilepsy and Behavior examined recent developments and highlighted areas where more research is needed in this area.
Sleep is an important component in the epilepsy disease state as 10% to 15% of seizures are sleep-related and more than 90% of sudden unexpected deaths from epilepsy occur during sleep. Seizure locations have been associated with significant circadian rhythms. Frontal lobe seizures are more likely to occur during sleep or early morning, and mesial temporal seizures are more likely to occur in the morning or late afternoon. Occipital seizures rarely occur during sleep and peak in the early evening.
Sleep / wake disorders are two to three times more likely to be diagnosed in patients with epilepsy than in the general population, with hypersomnia being the most common. Other common problems include insomnia, restless legs syndrome and sleep bruxism, and sleep-related breathing disorders. These problems are a problem in this patient population because poor quality sleep is associated with decreased seizure control. Treatment for sleep apnea reduces seizures in many patients.
Patients with genetically generalized epilepsy, particularly juvenile myoclonic epilepsy (JME), are at increased risk of poor seizure control during periods of sleep deprivation. People with JME, especially if they are teenagers, are more likely to have decreased frontal executive function, which increases the likelihood of maintaining unhealthy sleeping habits.
Generalized and focal interictal epileptiform discharges during sleep were most likely to occur during non-rapid eye movement (NREM) 3, NREM 1, or NREM 2 periods and were unlikely to occur during REM sleep. These discharges were associated with sleep fragmentation in most patients.
An important function of NREM sleep is to strengthen memory and learning. A study of verbal memory over 1 week found a negative correlation with the frequency of hippocampal spikes during sleep, which may be due to an interruption in the attack of hippocampal-neocortical information transfer during NREM sleep.
The results showed that knowledge gaps remain regarding the complex two-way relationship between sleep and epilepsy. The review authors concluded, “New developments and directions in understanding the two-way relationships between sleep and epilepsy will encourage clinicians to consider the effects of sleep (or lack thereof) in people with epilepsy and researchers [to] Discover what else we need to know. ”
Grigg-Damberger M, Foldvary-Schaefer N. Bidirectional relationships of sleep and epilepsy in adults with epilepsy. Epilepsy Behavior Published online February 6, 2021. doi: 10.1016 / j.yebeh.2020.107735