Background & Aims
Keeping the body within physiological ranges is crucial for survival. This ability relies on accurate interoception – the ability to predict, perceive, and respond to inputs coming from within the body. Interoceptive perceptions such as deep tissue pressure pain, heartbeat and temperature are conducted via thin fibers of the spino-cranial lamina 1 tract and the glossopharyngeal and vagal cranial nerves. They are then processed by regions including brainstem nuclei, the insula, and the anterior cingulate cortex. Dysfunction in interoception has been associated with various mood and pain disorders. Its modulation could therefore lead to symptom improvement. Given the site of action, transauricular vagal nerve stimulation (taVNS) may be used. However, little is known about the scale, duration, and mechanism of its potential interoceptive modulation. Hence, this study will explore these taVNS-shortcomings with a focus on deep muscular pressure pain, heartbeat, and thermal perception.
Methods
20 healthy subjects will complete a double-blinded, randomized, crossover study (Clinical trial registry pending, Ethics Region Nord Jylland Denmark N-20230022). In both arms, subjects will get 20minutes of electrical stimulation (200µs duration, 20Hz, 30seconds on and 30seconds off, at a personalized intensity). Connected to a digitimer, the main intervention is left concha cymba taVNS (NEMOS, CerboMed GmbH, Erlangen) and the active control is left earlobe stimulation (Ambu, Neuroline electrodes, Bordeaux). A blinding assessment will be collected. Main outcomes are pressure pain thresholds and temporal summation of pain acquired via calf cuff-pressure algometer (Nocitech, Aalborg University). Heartbeat perception, assessed via the heartbeat counting task, and thermal perception, assessed using a thermal grid (LabQST), are also primary outcomes. Secondary outcomes are conditioned pain modulation, resting state electroencephalography, electrocardiography, and pupillary light reflexes.
Results
The study is currently in the data acquisition phase. Pilot data demonstrates feasibility of the study. As such, results can be expected to be presented in August.
Conclusions
This study is likely to clarify whether, and for how long, taVNS may modulate interoceptive channels of deep muscular pressure pain, heartbeat, and thermal perception. If demonstrated efficient, follow-up studies will aim to validate similar manifestations of taVNS in pain patients having abnormal interoceptive channels.
References
1.Barrett, L.F. and Simmons, W.K. (2015) ‘Interoceptive predictions in the brain’, Nature Reviews Neuroscience, 16(7), pp. 419–429. doi:10.1038/nrn3950.
2.Khalsa, S.S. and Lapidus, R.C. (2016) ‘Can interoception improve the pragmatic search for biomarkers in psychiatry?’, Frontiers in Psychiatry, 7. doi:10.3389/fpsyt.2016.00121.
3.Kiverstein, J., Kirchhoff, M.D. and Thacker, M. (2022) ‘An embodied predictive processing theory of Pain experience’, Review of Philosophy and Psychology, 13(4), pp. 973–998. doi:10.1007/s13164-022-00616-2.
4.Poppa, T. et al. (2022) ‘Auricular transcutaneous vagus nerve stimulation modulates the heart-evoked potential’, Brain Stimulation, 15(1), pp. 260–269. doi:10.1016/j.brs.2021.12.004.
5.Schmitt, C.M. and Schoen, S. (2022) ‘Interoception: A multi-sensory foundation of participation in Daily Life’, Frontiers in Neuroscience, 16. doi:10.3389/fnins.2022.875200.
6.Sterling, P. (2012) ‘Allostasis: A model of predictive regulation’, Physiology & Behavior, 106(1), pp. 5–15. doi:10.1016/j.physbeh.2011.06.004.
Presenting Author
Laura De Herde
Poster Authors
Laura De Herde
MSc
CNAP, Aalborg University
Lead Author
Steffen Frahm
M.Sc.
Integrative Neuroscience group, Center for Neuroplasticity and Pain (CNAP), Aalborg University
Lead Author
Claus Graff
M.Sc
Aalborg University
Lead Author
Thomas Gomes Nørgaard dos Santos Nielsen
PhD
Lead Author
Thomas Graven-Nielsen
Thomas Graven-Nielsen
Lead Author
Hartwig Roman Siebner
Prof
Danish Research Centre for Magnetic Resonance, Centre for Functional and Diagnostic Imaging and Rese
Lead Author
Daniel de Andrade
University of Aalborg
Lead Author
Topics
- Treatment/Management: Interventional Therapies – Neuromodulation