Prism adaptation effects in complex regional pain syndrome: A therapo-physiological single case experimental design exploratory report

ABSTRACT

Complex Regional Pain Syndrome (CRPS) is an invalidating chronic condition that can occur after an acute peripheral lesion. Prism adaptation therapy is regarded as a promising tool to improve chronic pain in this syndrome but the mechanisms which lead to pain amelioration remain unknown. In this exploratory report we performed a retrospective analysis of longitudinal data collected from a single, atypical patient, who showed hyper-attention toward her affected (left) hand. Repeated assessments of pain and spatial neglect made during the course of the prism adaptation treatment revealed differential contributions of the two hands to adaptation-induced pain reduction. Treatment response appeared to be associated with a relative modification of the spatial behaviour of the two hands. This case study provides a new example of pain relief following prismatic deviation away from the pathological side.

KEYWORDS:

• CRPS
• Chronic pain
• Prism adaptation
• Pathophysiology
• Therapo-physiology

Acknowledgements

The authors wish to thank AZ for her outstanding patiency, Sonia Alouche, Jean-Louis Borach, Anne Cheylus, Justine Epinat-Duclos, Eric Koun, Romeo Salemme, Frédéric Volland for their administrative and technical support. This work was supported by fundings from LABEX CORTEX, Inserm, CNRS, Université de Lyon and Hospices Civils de Lyon.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Notes

1 The visible two-order alternating pattern of the results is due to the fact that each day contained two adaptation sessions, each of which was preceded by a "pre" measure and followed by a "post" measure. This alternating pattern represents a short-term effect that is not meaningful in the context of this study in which we were interested in the clinical effects at the time scale weeks.