1340 Frontal Lobe Epilepsy Presenting as Parasomnia in a Child on BiPAP for Severe Obstructive Sleep Apnea

Abstract Introduction Parasomnias are common in pediatric patients with obstructive sleep apnea (OSA), but true nocturnal seizures can closely mimic parasomnia-like behaviors. Distinguishing between the two is critical, particularly in children using positive airway pressure (PAP), where sleep fragmentation, mask intolerance, or residual OSA may confound the clinical picture. We present a case of a child on BiPAP for severe OSA who was evaluated for worsening sleepwalking and was ultimately diagnosed with frontal lobe epilepsy during PAP titration polysomnography (PSG). Report of case(s) A 9-year-old male with asthma and history of adenotonsillectomy initially presented in 2023 with a baseline PSG demonstrating severe OSA with an apnea–hypopnea index (AHI) of 34.5 events/hour (obstructive AHI 33.8, REM AHI of 82.5, and an oxygen saturation nadir of 61% during REM) without evidence of hypoventilation. He subsequently underwent PAP titration, resulting in a recommendation for BiPAP at 13/7 cm of water due to persistent hypoxemia on CPAP. Over the next two years, he demonstrated good clinical response to therapy; however, at follow-up, family reported increasing episodes of sleepwalking and mask discomfort, as well as nocturnal episodes during which he would suddenly wake up yelling and rip off his mask, leading to poor PAP adherence. A repeat PAP titration with extended EEG was performed. During the study, interictal EEG abnormalities with frontal dominance were noted, including arrhythmic delta activity over the frontal regions. Five discrete nocturnal events characterized by dystonic upper extremity posturing and brief hypermotor activity were recorded. These episodes were consistent with frontal lobe epilepsy rather than parasomnia. From a respiratory standpoint, he continued to demonstrate persistent severe OSA requiring continued PAP therapy. Given the abnormal EEG findings, the patient was referred to pediatric neurology and was started on anti-seizure medications. Conclusion This case highlights the importance of maintaining a broad differential diagnosis when evaluating parasomnia-like behaviors in children with OSA, especially those on PAP therapy. Repeat PSG with extended EEG monitoring played a pivotal role in differentiating epileptic events from parasomnia and allowed timely initiation of antiepileptic therapy. Support (if any)