Comorbidity of Narcolepsy and Obstructive Sleep Apnea: A Case Report

Excessive daytime sleepiness (EDS) is the main symptom in narcoleptic patients. Obstructive sleep apnea (OSA) is known to be related to EDS. We describe three cases of narcolepsy that were misdiagnosed as other diseases or as OSA alone. Three patients with the onset of snoring and daytime sleepiness in adolescence were referred to our sleep center. Polysomnography showed severe sleep apnea. Their multiple sleep latency test (MSLT) met the diagnostic criteria of narcolepsy. Another patient who had EDS and snoring showed severe OSA and positive results on MSLT. However, longitudinal clinical symptoms of this patient differed from those of the three cases. EDS was ameliorated in all four patients following the treatment with psychostimulants and the application of Continuous positive airway pressure. Patients suffering from EDS may be co-diagnosed with narcolepsy and OSA. Clinicians should be aware of the possibility of false-positives of MSLT and the patient’s longitudinal clinical course.