Factors Affecting Sleep and Wakefulness in People with Epilepsy: A Narrative Review

The importance of sleep has been reported for decades. Epilepsy is a heterogeneous disorder comprising multiple elements that might influence sleep and wakefulness. Notably, animal studies show disruptions of the circadian molecular system in different models of epilepsy, along with altered rest-activity and other circadian rhythms. So far, studies of molecular circadian systems in people with epilepsy are lacking, prompting further research. Seizures-the primary and most debilitating symptom of epilepsy-and interictal activity disrupt regular sleep and sleep-wake rhythms. Alterations in one's sleep structure are seen in both drug-naïve and drug-resistant patients with epilepsy. In particular, low sleep efficiency, a reduction in total sleep time, and changes in sleep stages were found in both homogenous and mixed samples of epilepsy patients. Both ictal and interictal activity were also shown to be associated with changes in peripheral circadian phase biomarkers such as melatonin and cortisol. Moreover, epilepsy comorbidities, antiseizure medications, and a variety of syndromes can be a cause of sleep problems or even sleep disorders. Sleep disorders vary depending on various comorbidities and syndromes, and encompass all major groups of sleep disorders defined in the International Classification of Sleep Disorders. Controversial findings on the effects of various antiseizure medications were found in the literature. However, medications such as benzodiazepines, gabapentinoids, and barbiturates are particularly associated with excessive daytime sleepiness. Overall, a sleep evaluation must be included in the management of every patient with epilepsy.