Behavioural evidence for vestibular stimulation as a treatment for central post-stroke pain
- 1Center for Brain and Cognition, University of California, San Diego, California, USA
- 2Department of Radiology, University of California, San Diego, California, USA
- 3Veterans Affairs San Diego Healthcare System, San Diego, California, USA
- Dr P D McGeoch, University of California, San Diego, Centre for Brain and Cognition, Mandler Hall, 9500 Gilman Drive, Mail Code 0109, La Jolla, CA 92093-0109, USA; pmcgeoch{at}mac.com
- Received 9 February 2008
- Revised 17 March 2008
- Accepted 19 March 2008
- Published Online First 11 June 2008
Abstract
Background: Central post-stroke pain (CPSP) is often resistant to treatment. We have previously proposed that caloric vestibular stimulation might alleviate it.
Methods: We conducted a single blind placebo controlled investigational study of caloric vestibular stimulation (CVS) in nine patients with CPSP. Participants rated their pain levels before and after the procedure on a 10 point scale.
Results: We found a significant immediate treatment effect of the cold water caloric stimulation with an average pain reduction of 2.58 points (SEM 0.52) for the experimental condition compared with 0.54 points (SEM 0.49) for the placebo conditions.
Conclusions: Participants who responded best to CVS had suffered strokes that spared and permitted activation of the dominant parieto-insular vestibular cortex (PIVC), which is known to be located in the non-dominant hemisphere. These findings tie in closely with the thermosensory disinhibition hypothesis for central pain, which leads us to propose that vestibular stimulation may alleviate CPSP from cross activation between the PIVC and the thermosensory cortex in the adjacent dorsal posterior insula. Alternatively, if one views vestibular function and thermoregulation as part of a larger interoceptive system that exists to maintain homeostasis, then it is possible they share a common integrative mechanism in the brainstem, which may act to reset the balance in central pain.
Footnotes
-
Competing interests: None.
-
Funding: Our work is partly funded by the C Robbins and R Geckler Foundations, neither of which had any direct input into this study.
-
Ethics approval: The institutional review board of University of California, San Diego, granted ethics approval for the study.
