Detecting autonomic response to pain in Rett syndrome

Abstract

Objective: To quantify pain response in girls affected by Rett syndrome (RTT) using electrodermal activity (EDA), a measure of skin conductance, reflecting sympathetic activity known to be modulated by physical and environmental stress. Methods: EDA increase, heart rate (HR) increase and Face Legs Activity Cry Consolability (FLACC) values calculated during venipuncture (invasive) and vital signs collection (non-invasive) events were compared with values calculated during a prior baseline and a RTT clinical severity score (CSS). Results: EDA and HR increase were significantly higher than baseline during venipuncture only and not significantly correlated with FLACC or CSS. EDA increase was the most sensitive measure of pain response. Conclusions: These preliminary findings revealed that motor impairment might bias non-verbal pain scales, underscore the importance of using autonomic measures when assessing pain and warrant further investigation into the utility of using EDA to objectively quantify RTT pain response to inform future RTT pain management.

Keywords:

• Electrodermal activity
• FLACC
• heart rate
• pain
• Rett syndrome
• skin conductance

Acknowledgments

We thank the children who participated in the study and their families, the nursing and phlebotomy staff of the CTSU at Boston Children’s Hospital.

Declaration of interest

W.E.K. is a consultant to Cydan, Neuren, Edison and Astra Zeneca. E.H. receives compensation from F. Hoffmann-La Roche to be on a clinical trial data and safety monitoring board. O.K. is a full-time employee and owns stock in F. Hoffmann-La Roche Ltd. The remaining authors report no conflicts. The authors are responsible for the content of the article. The project was funded by the International Rett Syndrome Foundation (Grant 2534), the Autism Speaks foundation (Grant 5795), the Translational Research Program at Boston Children’s Hospital, Boston Children’s Hospital Intellectual and Developmental Disabilities Research Center P30 HD18655, and by the Harvard Catalyst–The Harvard Catalyst Clinical and Translational Research Center (NCATS grant #8UL1TR000170 and financial contributions from Harvard University and its affiliated academic healthcare centres). The content is solely the responsibility of the authors and does not necessarily represent the official views of Harvard Catalyst, Harvard University and its affiliated academic healthcare centres, the International Rett Syndrome Foundation, the Autism Speaks foundation or the National Institute of Health.