Vagus nerve stimulation, sleep apnea, and CPAP titration

Area of Science:

• Neurology
• Sleep Medicine
• Medical Devices

Background:

• Epilepsy and obstructive sleep apnea (OSA) frequently coexist and can worsen each other.
• Vagus nerve stimulation (VNS) is an adjunctive treatment for epilepsy, but can negatively impact respiration during sleep.
• VNS therapy has been shown to exacerbate obstructive sleep apnea/hypopnea syndrome (OSAHS) by increasing apnea and hypopnea events.

Observation:

• VNS therapy can interfere with the effective titration of continuous positive airway pressure (CPAP).
• In a patient with medically intractable epilepsy and severe OSAHS, standard VNS cycling prevented adequate CPAP titration.
• Disabling VNS allowed for successful CPAP titration, achieving effective treatment for OSAHS.

Findings:

• Adequate CPAP titration was not achievable with the patient's VNS device in its standard on/off cycling mode.
• A nasal CPAP pressure of 13 cm H2O effectively treated severe OSAHS when the VNS device was turned off.
• VNS cycling parameters may need adjustment or VNS deactivation for effective OSAHS management in co-occurring epilepsy patients.

Implications:

• Polysomnography screening before VNS implantation may be crucial for identifying patients with undiagnosed OSA.
• Consideration of VNS cycling parameters or deactivation is important for managing patients with both epilepsy and OSAHS.
• This case highlights the complex interplay between VNS therapy and respiratory control during sleep, impacting OSA treatment efficacy.