Kimpara K1, Sakuma S1,2, Adachi K3, Yang H1, Tanaka M1, Tawara Y1, Arizono S1, Terada K2
1Graduate School of Rehabilitation Sciences, Seirei Christopher University, Hamamatsu, Japan, 2Terada Pain Clinic, Hamamatsu, Japan, 3Seirei Mikatahara General Hospital, Hamamatsu, Japan
Background: Chronic pain is one of the major health issues in the world. Treatment of chronic pain focuses on the brain activation as well as physical conditions. Activating the prefrontal cortex is one of key points for treatment of chronic pain. However there are not many studies to identify the association between activation of prefrontal cortex and chronic pain recovery. Activating the prefrontal cortex needs dual task during exercises and treatments. The dual task has possibilities to treat the chronic pain.
Purpose: The purpose of this study was to clarify whether activation of prefrontal cortex in dual task leaded to the improvement of the neurophysiological mechanism of pain in patients with chronic pain.
Methods: A cross sectional study was utilized. Ten patients with chronic pain over six months (average age:25.7±8.01) were recruited from pain clinic in Hamamatsu city and they were randomly assigned to dual task (n=10) and control (n=10) groups. Numerical Rating Scale (NRS), Pain Catastrophizing Scale (PCS), Hospital Anxiety, Depression Scale(HADS) and pressure pain thresholds(PPTs) were measured. Functional near infrared spectroscopy (fNIRS) was attached to the prefrontal cortex and galvanic skin response (GSR) was applied to the toes. The patients were at resting position during the evaluation.The experiment evaluated temporal summation (TS) and conditioned pain modulation (CPM) after 4 minutes of rest.
The dual task group performed different exercise on the left and right upper limbs for 20 seconds. The control group performed the same exercise on the left and right upper limbs. TS and CPM were reevaluated after the exercise. For the comparison of the 2 groups, statistical analysis was performed by using SPSS (version 22)(α＜0.05).
Results: There was not significant difference in baseline evaluation between the two groups．PCS and HADS were significantly improved ( p .05) and the left dorsolateral prefrontal cortex was significantly activated at the time of evaluation of TS and CPM (p .05) in the double task group. Additionally, the dual task group activated descending pain inhibitory system (p .05).
Conclusion(s): This study found that the dual task was activated the dorsolateral prefrontal cortex, and it decreased degree of depression and catastrophizing in patients with chronic pain. In fact, activation of the dorsolateral prefrontal cortex stimulated descending pain modulatory system.
The TS and CPM in the dual task group were more activated to compare with control group. The results suggested that periaquedctal gray was stimulated by the prefrontal cortex activity and descending pain inhibitory system was acted. As the results, the pain stimulation of the dorsal horn of the spinal cord was decreased. Those mechanism contributed to the improvement of depression of PCS and HADS which were emotional factors of chronic pain. Thus, emotion involves in chronic pain and treating emotion is crucial to ease chronic pain.
Implications: Combining physical function and brain function trainings is essential for treatments of chronic pain so that physical therapy for chronic pain can be more effective than approaching only physical function.
Keywords: chronic pain, neurophysiological of pain, dual task
Funding acknowledgements: This study has not received subsidy
Purpose: The purpose of this study was to clarify whether activation of prefrontal cortex in dual task leaded to the improvement of the neurophysiological mechanism of pain in patients with chronic pain.
Methods: A cross sectional study was utilized. Ten patients with chronic pain over six months (average age:25.7±8.01) were recruited from pain clinic in Hamamatsu city and they were randomly assigned to dual task (n=10) and control (n=10) groups. Numerical Rating Scale (NRS), Pain Catastrophizing Scale (PCS), Hospital Anxiety, Depression Scale(HADS) and pressure pain thresholds(PPTs) were measured. Functional near infrared spectroscopy (fNIRS) was attached to the prefrontal cortex and galvanic skin response (GSR) was applied to the toes. The patients were at resting position during the evaluation.The experiment evaluated temporal summation (TS) and conditioned pain modulation (CPM) after 4 minutes of rest.
The dual task group performed different exercise on the left and right upper limbs for 20 seconds. The control group performed the same exercise on the left and right upper limbs. TS and CPM were reevaluated after the exercise. For the comparison of the 2 groups, statistical analysis was performed by using SPSS (version 22)(α＜0.05).
Results: There was not significant difference in baseline evaluation between the two groups．PCS and HADS were significantly improved ( p .05) and the left dorsolateral prefrontal cortex was significantly activated at the time of evaluation of TS and CPM (p .05) in the double task group. Additionally, the dual task group activated descending pain inhibitory system (p .05).
Conclusion(s): This study found that the dual task was activated the dorsolateral prefrontal cortex, and it decreased degree of depression and catastrophizing in patients with chronic pain. In fact, activation of the dorsolateral prefrontal cortex stimulated descending pain modulatory system.
The TS and CPM in the dual task group were more activated to compare with control group. The results suggested that periaquedctal gray was stimulated by the prefrontal cortex activity and descending pain inhibitory system was acted. As the results, the pain stimulation of the dorsal horn of the spinal cord was decreased. Those mechanism contributed to the improvement of depression of PCS and HADS which were emotional factors of chronic pain. Thus, emotion involves in chronic pain and treating emotion is crucial to ease chronic pain.
Implications: Combining physical function and brain function trainings is essential for treatments of chronic pain so that physical therapy for chronic pain can be more effective than approaching only physical function.
Keywords: chronic pain, neurophysiological of pain, dual task
Funding acknowledgements: This study has not received subsidy
Topic: Pain & pain management
Ethics approval required: Yes
Institution: Seirei Christopher University
Ethics committee: Seirei Christopher University Ethics Committee
Ethics number: 17-043-02
All authors, affiliations and abstracts have been published as submitted.
