Obstructive Sleep Apnea and Epilepsy: Study from a Tertiary Care Centre in Southern India

Patients with neurologic disorders seem to have a greater prevalence of sleep disturbance than normal subjects.A study done by Miller et al. 5 showed that the majority of patients with epilepsy had complaints regarding sleep.A polysomnographic investigation by Malow et al. 6 showed that nearly one-third of patients with medically refractory epilepsy had a respiratory disturbance index of more than 56.Therapeutic intervention for epilepsy may also increase the risk of sleep apnea.Some of the anticonvulsant medications have weight gain as a side effect and may alter respiratory regulation.Valproate, vigabatrin, and gabapentin are well known to accelerate obesity, which increases the likelihood of sleep apnea.Benzodiazepines and barbiturates may cause carbon dioxide and oxygen desaturation and increase upper Abstract Objective: Obstructive sleep apnea (OSA) is a sleep-related disorder resulting in hypoxemia and epilepsy itself causes central and obstructive apnea.Studies looking at this relation are limited.Hence, we aimed to examine the incidence of OSA in patients with epilepsy.To estimate the prevalence of OSA in patients with epilepsy.To study seizure characteristics among patients with comorbid OSA.Methods: Patients above 18 years, and diagnosed with seizures/epilepsy attending our neurology epilepsy clinic for the past 1 year were included in our study.Patients with metabolic causes, psychogenic seizures, and symptomatic or provoked seizures were excluded.Retrospective analysis was done.Patients were screened for OSA using the Berlin questionnaire.Those with high scores underwent complete clinical evaluation, evaluation using the Epworth Sleepiness Scale, and diagnostic polysomnography with a portable ResMed USA device.Univariate binary logistic regression analysis was used to obtain the results.Results: Out of 195 epileptic patients screened, 63 patients scored high on the Berlin questionnaire.Of them, 4 had severe OSA, 6 had moderate OSA, and 11 had mild OSA based on polysomnography.Prevalence of OSA is 33.3%.Age and body mass index were strongly associated with OSA syndrome, (p values 0.001 and 0.0003).There is no association between seizure type and the occurrence of OSA (p value=0.5).Conclusion: Even though we found no direct relationship, we observed that treating underlying OSA reduced the frequency of seizures, resulting in the patient's overall well-being.