(A1208) Challenging Hypoglossal Nerve Stimulation Implantation in a Patient with Neurofibromatosis and Suspected Schwannoma

Introduction: Hypoglossal nerve stimulation (HNS) is an effective treatment for obstructive sleep apnea (OSA) in patients who fail CPAP therapy. However, in individuals with neurofibromatosis (NF), neural sheath abnormalities can complicate device implantation and efficacy. This case highlights the challenges of HNS in a patient with NF and suspected hypoglossal nerve pathology.

Methods: A 66-year-old female with severe OSA (Respiratory Event Index 52.2) refractory to CPAP therapy was evaluated for HNS. The patient, previously diagnosed with NF, had imaging six years prior revealing thickening of spinal nerve roots and trigeminal branches. Preoperative drug-induced sleep endoscopy demonstrated anteroposterior collapse of the velum and tongue base without concentric collapse. Intraoperatively, the hypoglossal nerve was identified but exhibited significant thickening proximally and along medial inclusion branches. Stimulation testing demonstrated weak and inconsistent nerve responses, and the cuff fit poorly due to nerve hypertrophy. The procedure was aborted after determining insufficient therapeutic efficacy.

Results: Test stimulation of the hypertrophic hypoglossal nerve induced minimal tongue protrusion, compromising the goal of airway patency. Postoperative imaging confirmed diffuse enlargement with increased enhancement of the hypoglossal nerve suggesting plexiform neurofibroma bilaterally.

Conclusions: HNS implantation in patients with NF1 requires careful preoperative imaging and intraoperative decision-making due to potential neural sheath abnormalities. Adaptable surgical strategies and device designs are essential for optimizing outcomes in this complex population.