Bedside Neuromodulation of Persistent Pain and Allodynia with Caloric Vestibular Stimulation

Trung T. Ngo; Wendy N. Barsdell; Phillip C. F. Law; Carolyn A. Arnold; Michael J. Chou; Andrew K. Nunn; Douglas J. Brown; Paul B. Fitzgerald; Stephen J. Gibson; Steven M. Miller

doi:10.3390/biomedicines12102365

Biomedicines (Oct 2024)

Bedside Neuromodulation of Persistent Pain and Allodynia with Caloric Vestibular Stimulation

Trung T. Ngo,
Wendy N. Barsdell,
Phillip C. F. Law,
Carolyn A. Arnold,
Michael J. Chou,
Andrew K. Nunn,
Douglas J. Brown,
Paul B. Fitzgerald,
Stephen J. Gibson,
Steven M. Miller

Affiliations

Trung T. Ngo: RECOVER Injury Research Centre, The University of Queensland and Surgical, Treatment & Rehabilitation Service (STARS), Herston, Brisbane, QLD 4029, Australia
Wendy N. Barsdell: Adelaide Neuropsychology, Adelaide, SA 5000, Australia
Phillip C. F. Law: Monash Biomedicine Discovery Institute, Department of Physiology, Monash University, Melbourne, VIC 3800, Australia
Carolyn A. Arnold: Caulfield Pain Management & Research Centre, Caulfield Hospital, The Alfred Health, Melbourne, VIC 3162, Australia
Michael J. Chou: Amputee Clinic, Caulfield Hospital, Melbourne, VIC 3162, Australia
Andrew K. Nunn: Amputee Clinic, Caulfield Hospital, Melbourne, VIC 3162, Australia
Douglas J. Brown: Spinal Research Institute, Austin Health, Melbourne, VIC 3084, Australia
Paul B. Fitzgerald: School of Medicine and Psychology, Australian National University, Acton, ACT 2600, Australia
Stephen J. Gibson: Caulfield Pain Management & Research Centre, Caulfield Hospital, The Alfred Health, Melbourne, VIC 3162, Australia
Steven M. Miller: Monash Biomedicine Discovery Institute, Department of Physiology, Monash University, Melbourne, VIC 3800, Australia

DOI: https://doi.org/10.3390/biomedicines12102365
Journal volume & issue: Vol. 12, no. 10
p. 2365

Abstract

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Background: Caloric vestibular stimulation (CVS) is a well-established neurological diagnostic technique that also induces many phenomenological modulations, including reductions in phantom limb pain (PLP), spinal cord injury pain (SCIP), and central post-stroke pain. Objective: We aimed to assess in a variety of persistent pain (PP) conditions (i) short-term pain modulation by CVS relative to a forehead ice pack cold-arousal control procedure and (ii) the duration and repeatability of CVS modulations. The tolerability of CVS was also assessed and has been reported separately. Methods: We conducted a convenience-based non-randomised single-blinded placebo-controlled study. Thirty-eight PP patients were assessed (PLP, n = 8; SCIP, n = 12; complex regional pain syndrome, CRPS, n = 14; non-specific PP, n = 4). Patients underwent 1–3 separate-day sessions of iced-water right-ear CVS. All but four also underwent the ice pack procedure. Analyses used patient-reported numerical rating scale pain intensity (NRS-PI) scores for pain and allodynia. Results: Across all groups, NRS-PI for pain was significantly lower within 30 min post-CVS than post-ice pack (p < 0.01). Average reductions were 24.8% (CVS) and 6.4% (ice pack). CRPS appeared most responsive to CVS, while PLP and SCIP responses were less than expected from previous reports. The strongest CVS pain reductions lasted hours to over three weeks. CVS also induced substantial reductions in allodynia in three of nine allodynic CRPS patients, lasting 24 h to 1 month. As reported elsewhere, only one patient experienced emesis and CVS was widely rated by patients as a tolerable PP management intervention. Conclusions: Although these results require interpretative caution, CVS was found to modulate pain relative to an ice pack control. CVS also modulated allodynia in some cases. CVS should be examined for pain management efficacy using randomised controlled trials.

Published in Biomedicines

ISSN: 2227-9059 (Online)
Publisher: MDPI AG
Country of publisher: Switzerland
LCC subjects: Science: Biology (General)
Website: http://www.mdpi.com/journal/biomedicines

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