Assessment of brainstem function with auricular branch of vagus nerve stimulation in Parkinson's disease

PLoS One. 2015 Apr 7;10(4):e0120786. doi: 10.1371/journal.pone.0120786. eCollection 2015.

Abstract

Background: The efferent dorsal motor nucleus of the vagal nuclei complex may degenerate early in the course of Parkinson's disease (PD), while efferent nucleus ambiguous, the principal source of parasympathetic vagal neurons innervating the heart, and afferent somatosensory nuclei remain intact.

Objective: To obtain neurophysiological evidence related to this pattern, we tested processing of afferent sensory information transmitted via the auricular branch of the vagus nerve (ABVN) which is known to be connected to autonomic regulation of cardiac rhythm.

Methods: In this cross-sectional observational study, we recorded (i) somatosensory evoked potentials (ABVN-SEP) and (ii) cutaneo-cardioautonomic response elicited by stimulation of the ABVN (modulation of heart-rate variability (HRV index; low frequency power, ln(LF), high frequency power, ln(HF); ln(LF/HF) ratio)) in 50 PD patients and 50 age and sex matched healthy controls. Additionally, auditory evoked potentials and trigeminal nerve SEP were assessed.

Results: Neither ABVN-SEP nor any of the other functional brainstem parameters differed between patients and controls. Although HRV index was decreased in PD patients, modulation of ln(LF/HF) by ABVN-stimulation, likely indicating cardiac parasympathetic activation, did not differ between both groups.

Conclusions: Findings do not point to prominent dysfunction of processing afferent information from ABVN and its connected parasympathetic cardiac pathway in PD. They are consistent with the known pattern of degeneration of the vagal nuclei complex of the brainstem.

Publication types

  • Comparative Study
  • Observational Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Brain Stem / physiology*
  • Case-Control Studies
  • Cross-Sectional Studies
  • Evoked Potentials, Somatosensory / physiology*
  • Female
  • Humans
  • Male
  • Middle Aged
  • Parkinson Disease / physiopathology*
  • Parkinson Disease / therapy*
  • Prognosis
  • Vagus Nerve Stimulation / methods*

Grants and funding

The study was supported by a junior research grant by the Medical Faculty, University of Leipzig (DW). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.