Sleep disordered breathing in children receiving vagus nerve stimulation therapy.

Objective: The effects of vagus nerve stimulation (VNS) on sleep disordered breathing (SDB) have been reported in limited case series. Detailed studies, particularly in the pediatric population, have not been performed. The primary purpose of this study is to describe clinical characteristics, polysomnographic findings, and management of children treated with VNS.

Methods: A retrospective review of medical records and polysomnography data was performed in patients ages 0-20 years old receiving VNS therapy for refractory epilepsy at Cincinnati Children's Hospital Medical Center.

Results: 22 subjects met the inclusion criteria. 50% were male. The mean age at the time of VNS insertion was 8.4 ± 4.0 years. The mean age at the first PSG was 10.6 ± 4.3 years. Common presentations to sleep clinics included snoring (77.3%), frequent nighttime awakening (68.1%), and parasomnias (63.6%). The median apnea-hypopnea index (AHI) was 4.5/hr (IQR 3.0-13.1) and the median obstructive index (OI) was 4.1/hr (1.5-12.8). Obstructive sleep apnea (OSA) was diagnosed after VNS insertion in 19 patients (86.4%), 8 of which (36.3%) had severe OSA. Six patients (27.3%) had significant hypoventilation. For management, 6 patients (27.2%) were treated with bilevel PAP, 3 patients (13.6%) with CPAP, 2 patients (9.1%) with ventilator, 4 patients (18.2%) with upper airway surgeries, and 9 patients (40.9%) received medications only.

Conclusions: SDB is common in pediatric patients with medically refractory epilepsy managed with VNS who were referred to sleep medicine clinics. Both OSA and nocturnal alveolar hypoventilation are relatively common in this population. Management of SDB often involves the use of positive airway pressure therapy or upper airway surgeries. Further studies are needed to assess the prevalence, risk factors, and the effect of treatments on epilepsy control. This study highlights the need for screening of SDB prior to and following VNS implantation.