Evaluation of sleep-related respiratory disorders (primary snoring-severe obstructive apnea syndrome) and epilepsy and their treatment on each other

INTRODUCTION: The most commonly encountered clinical presentations in neurology practice include epilepsy and sleep-related respiratory disorders. Sleep-related respiratory disorders present a clinical spectrum ranging from primary snoring to severe obstructive sleep-apnea syndrome (OSAS). These disorders may occur as an isolated condition as well as they may be seen in association with each other. It was planned to compare general parameters between groups for association of sleep-related respiratory disorders (primary snoring-severe OSAS) and epilepsy as well as to evaluate effects of both clinical conditions on each other. MATERIALS and METHODS: The patients followed in outpatient sleep clinic-sleep laboratory and outpatient clinic of epilepsy of Neurology Department of Celal Bayar University between January 2006 and June 2022 were retrospectively reviewed following approval of the Ethics Committee. Patients with association of primary snoring and epilepsy as well as those with association of severe obstructive sleep apnea syndrome (OSAS) and epilepsy were included. The parameters for which in-group (primary snoring-epilepsy and severe OSAS-epilepsy) and between-groups (between two groups for primary snoring-epilepsy/severe OSAS-epilepsy) comparisons were made included demographics (age at the time of presentation, age at which epilepsy started, duration of epilepsy, gender, body mass index), medical history (type of birth, duration of epilepsy, duration of snoring), relationship of the seizures with sleep, other co-morbidities (atherosclerotic risk factors – hypertension, diabetes mellitus, heart failure, coronary arterial disease, ischemic stroke), features of epilepsy (type of the seizures, findings on electroencephalography (EEG), and medications used for epilepsy). Most importantly, it was planned to effects of the treatment for both between-groups and in-group snoring and respiratory disorders on the epileptic seizures, EEG, and anti-epileptic medication before and after the treatment was given. Additionally, effects of the anti-epileptic medications which were also used after treatment of snoring and exerted decrease in dosage and number of the drugs on the sleep structure and respiratory disorders were also investigated. RESULTS: A total of 28 patients with association of primary snoring and epilepsy and 28 patients with association of severe OSAS and epilepsy based on the polysomnography examination were included in the study. Age of the patients, age at the onset of epilepsy were higher and duration of epilepsy was significantly longer in the severe OSAS group. When the patients in both groups without difference in terms of type of birth were evaluated for body-mass index (BMI), it was seen that BMI was remarkably higher in the group with severe OSAS. In regard to the co-morbidities, they existed in both groups but were more common in the group with severe OSAS. In addition to the sleep-related respiratory disorders, hypersomnia is also one of the commonly reported symptoms. Epworth's sleepiness scores were higher in the group of severe OSAS and in the patients with symptom of hypersomnia compared to other groups and patients. Some of the epileptic seizures occurring in the patients secondary to OSAS and sleep-related respiratory disorders tended to occur during the sleep. The epileptic seizures were grouped as generalized tonic-clonic, myoclonic, absence and complex-partial seizures with tonic-clonic seizures observed to be more common in the group of OSAS and generalized tonic-clonic and complex-partial seizures observed to occur more commonly in the group with primary snoring although they were relatively rare. In regard to EEG examination, the findings were grouped as normal, paroxysmal activity disorder, paroxysmal activity disorder with epileptiform potential, generalized epileptiform discharges, and localized epileptic activity. The group with primary snoring showed normal and paroxysmal activity disorder more commonly whereas it was remarkable that only three subjects were normal and tendency to be pathologic on EEG was significantly higher in the group with severe OSAS. In addition to severity of the seizures, their frequency was also higher in the group with severe OSAS. It was found that severity and frequency of the seizures decreased significantly in the both groups following treatment for sleep-related respiratory disorders and snoring, pathological findings disappeared on EEG, and symptom of hypersomnia decreased in the group with severe OSAS, and number and dosage of the antiepileptic medications significantly decreased secondary to these changes. It was also observed that decreased dosage and number of the antiepileptic medications led to improved structure of the sleep and symptoms of snoring decreased due to weight-loss as a consequence of antiepileptic medications. As a consequence of all treatments, reciprocal improvement occurred in clinical presentation of the epilepsy and respiratory disorders. DISCUSSION: Number and dosage of the medications for epilepsy is decreased by treatment of the sleep-related respiratory disorders, leading to improved structure of sleep and decreased symptoms of snoring by reciprocal interaction. Sleep pattern and symptoms of respiratory disorders during sleep should be absolutely queried in the patients with epilepsy. Understanding the relationship between epilepsy and sleep disorders, determining and treating the co-morbid conditions related to sleep will contribute to decrease in day-time sleepiness, to increase in quality of life, and to control epileptic seizures. Controlling the epileptic seizures and regulating the medications lead to increase in quality of sleep and remarkable decrease in such symptoms as snoring, apnea, and excessive day-time sleepiness.