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Chemosensory function in patients with vagal nerve stimulators
Annette Kirchner1, Basile N Landis, Matthias Haslbeck
1Department of Neurology, University of Erlangen-Nürnberg, Erlangen, Germany.
Summary
Vagal nerve stimulation (VNS) impacts how the brain processes smell. Electrophysiological measures show VNS influences olfactory event-related potentials, suggesting a role in olfactory information processing.
Area of Science:
- Neuroscience
- Sensory Physiology
- Medical Devices
Background:
- Chemosensory perception relies on integrated sensory inputs.
- Vagal nerve stimulation (VNS) is an established therapy for conditions like epilepsy.
- The effect of VNS on chemosensory functions, particularly olfaction and gustation, remains underexplored.
Purpose of the Study:
- To investigate the influence of left-sided vagal nerve electrical stimulation on gustatory and olfactory function.
- To assess changes in olfactory processing using electrophysiological methods during VNS.
Main Methods:
- 11 participants with VNS underwent psychophysical testing for gustation and olfaction.
- Olfactory function was evaluated using event-related potentials (ERPs) and air-dilution olfactometry with H2S.
- VNS was applied in two conditions: 'on' and 'off', with randomized session order.
Main Results:
- Vagal nerve stimulation (VNS) led to prolonged P2 latencies in olfactory ERPs.
- Patients experiencing therapeutic seizure control benefits showed increased olfactory ERP amplitudes during VNS 'on' compared to 'off' periods.
- Psychophysical tests indicated potential alterations in olfactory and gustatory function.
Conclusions:
- Electrophysiological data suggest VNS significantly influences the processing of olfactory information.
- The findings highlight a potential neurophysiological link between VNS and chemosensory pathways.
- Further research is warranted to elucidate the mechanisms and clinical implications of VNS on smell and taste.
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