2. Why is PSG recommended in patients undergoing VNS implantation?
Emergence or worsening of apneas and hypopneas coinciding with VNS activation has been reported in adults and children with epilepsy. The underlying mechanisms are unclear, with both central and peripheral mechanisms proposed. A clinical diagnosis of OSA results in up to one-third of adult cases. Lower stimulating frequencies or prolonging off-time may prevent OSA exacerbations. The VNS device manufacturer recommends screening for OSA and consideration of PSG prior to and following VNS device implantation.
3. How can epilepsy providers screen patients with epilepsy for OSA?
Clinical instruments such as the STOP-BANG Questionnaire ( Snoring, Tiredness/fatigue/sleepiness, Observed apnea, high blood Pressure, BMI >35kg/m 2, Age >50 years, Neck circumference >40 cm [>16 in], and male Gender) can help identify patients with high probability of OSA. Patients with 3 or more positive responses on the STOP-BANG Questionnaire are considered high risk. High-risk patients should be referred for PSG for diagnostic confirmation.
