1157 Obstructive Sleep Apnea Symptoms Caused by an Occult Seizure Disorder with a Brain Tumor Focus

Abstract Introduction Complex nocturnal behaviors are one of the most difficult diagnostic challenges in sleep medicine. The sensitivity of electroencephalography (EEG) varies with the study duration, epileptogenic lesion location, electrode placement, and the presence of events. A normal isolated EEG is insufficient to exclude an underlying seizure disorder particularly when diagnostic uncertainty remains. Polysomnography (PSG) is the gold standard for the evaluation of obstructive sleep apnea (OSA), and that has demonstrated a bidirectional relationship between OSA and comorbid epilepsy. This case report highlights an adolescent male with seizure-like symptoms initially diagnosed with OSA with refractory nocturnal episodes on continuous positive airway pressure (CPAP) for years until his eventual clinical diagnosis that was prompted by a repeat PSG. Report of case(s) A 14-year-old biological male with a history of snoring and excessive daytime sleepiness reported multiple episodes of unresponsiveness during sleep associated with shaking activity and self-reported desaturation at home. Initial episodes terminated upon repositioning of his body, however episodes and symptoms persisted despite treatment with positional therapy and CPAP. He had no clinical episodes during an unrevealing 72-hour EEG study. A repeat diagnostic PSG demonstrated an apnea-hypopnea index (AHI4%) of 1.1 events/hour, an AHI3A of 5.3 events/hour, and an SpO2 nadir of 92%. When the lights were turned on the patient exhibited repetitive facial movement upon awakening with poly-spikes on the corresponding EEG leads. This was followed by an inpatient admission for continuous EEG that demonstrated focal to bilateral tonic-clonic seizure during sleep of left-sided origin. MRI showed a 1.7 cm left basal temporal lobe tumor that was likely the seizure focus. He was discharged on levetiracetam, and ultimately underwent a posterior temporal lesion resection with resolution of his symptoms, including paroxysmal events and excessive daytime sleepiness. Conclusion Suspected nocturnal seizures often requires comprehensive and repeated testing modalities as an interictal EEG may fail to detect a seizure disorder and the presence of OSA does not eliminate the possibility of comorbid epilepsy. It is paramount to maintain a heightened index of suspicion as untreated OSA and epilepsy may have additive detrimental health effects. Appropriate identification as in our case may have a curative effect. Support (if any)