Long-term development of stimulation intensity of upper airway stimulation

Introduction:

In selective upper airway stimulation (sUAS) different stimulation thresholds can be determined. The sensation threshold (ST) indicates at which stimulation intensity the patient perceives the stimulation for the first time, while the functional threshold (FT) represents the stimulation intensity at which tongue protrusion over the lower teeth is first observed. The aim of this study was to investigate the development of stimulation intensity over the observation period of three years.

Methods:

All patients who received an upper airway stimulation system since December 2013 and showed constantly a bipolar configuration over the observation period were included. ST, FT, the titrated stimulation amplitude and the apnea-hypopnea index (AHI) were recorded.

Results:

A total of 82 patients were enrolled (gender: 69 m, 13 f, age: 60 ± 11 years, BMI: 29. 8 ± 4.0 kg/m²). Two months after surgery (M2) the median ST was 0.8 ± 0.5V. During the observation period of 36 months, no significant change of ST was observed. Thus, after 36 months (M36) the median ST was 1.0 ± 0.4V (p = 0.12). Similar results were found for FT and the titrated stimulation amplitude. The AHI decreased significantly from 31.4 ± 3.1/h to 5.7 ± 5.2/h at M36 (p < 0.05).

Conclusion:

The stimulation intensity in the sUAS shows no significant change over three years. With constant stimulation intensity, AHI was significantly reduced during the observed period of time. This indicates that the stimulation threshold of the hypoglossal nerve does not change during stimulation therapy.

Publication History

Publication Date:
23 April 2019 (online)