Abstract
Background
Vagus nerve stimulation (VNS) is a palliative treatment for refractory epilepsy that can induce a sleep apnea syndrome (SAS). Until now, prevalence of VNS-induced SAS and risk factors for developing it have barely been studied. The purpose of this study is to estimate the prevalence of a VNS-induced SAS and to identify if any clinical variable correlates with development of SAS after VNS implantation.
Methods
We analyzed the computerized medical records of 18 adults treated for refractory epilepsy who were implanted with a VNS at the University Hospital of Lausanne (CHUV), Switzerland between May 2008 and May 2017. The patients underwent a polygraphy (PG) or a polysomnography (PSG) before and after VNS implantation to screen for SAS. We compared retrospectively demographic variables, variables related to the epilepsy, and to the device’s parameters between the patient with and without SAS.
Results
In out cohort the prevalence of VNS-induced SAS was 27.8%. We did not find any statistically significant difference between the variables in the two groups but we found some trends in terms of medication, intensity of the stimulation and OFF time of the device.
Conclusion
The relatively high SAS prevalence that we observed and the lack of identified risk factors for developing SAS suggest that a screening for SAS before and after VNS implantation may represent a reasonable practice for every adult patient.