Behavioural evidence for vestibular stimulation as a treatment for central post-stroke pain.
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.
McGeoch
P D
PD
Centre for Brain and Cognition, University of California, San Diego, La Jolla, CA 92093-0109, USA. pmcgeoch@mac.com
Williams
L E
LE
Lee
R R
RR
Ramachandran
V S
VS
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002150:Caloric Tests; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010146:Pain / Q000175:diagnosis / Q000209:etiology*; D059408:Pain Management; D010147:Pain Measurement; D010812:Physical Stimulation / Q000379:methods*; D012720:Severity of Illness Index; D020521:Stroke / Q000150:complications*; D013697:Thermosensing / Q000502:physiology*; D014722:Vestibule, Labyrinth / Q000502:physiology*