Sakuma S1,2, Kimpara K2, Yang H2, Tanaka M2, Tawara Y2, Arizono S2, Terada K1
1Terada Pain Clinic, Hamamatsu, Japan, 2Graduate School of Rehabilitation Sciences, Seirei Christopher University, Hamamatsu, Japan
Background: Physical therapy based on the neurophysiological mechanism of pain is essential for the treatment of chronic pain. Using physical therapy in combination with medicine such as opioid. One of causes of chronic pain is plastic changes of the central nervous system under a long term pain. The previous studies showed that exercise improved pain intensity and anxiety in patients with the chronic pain. However it is not clear how exercise reforms the neurophysiological mechanism of pain.
Purpose: The aim of this study was to clarify the effects of exercise on the neurophysiological mechanism of pain.
Methods: Cross-sectional study was utilized. Thirty patients with chronic pain lasting over six months were recruited from pain clinic in Hamamatsu city Japan and divided into two groups (exercise group (n=15) and control group (n=15)). All participants were under medication. Firstly, numerical Rating Scale (NRS), Pain Catastrophizing Scale (PCS), Hospital Anxiety, Depression Scale (HADS) and determined pressure pain thresholds (PPTs) were measured in both groups. Functional near infrared spectroscopy (fNIRS) and galvanic skin response (GSR) were then attached at the resting position. Temporal summation (TS) and conditioned pain modulation (CPM) were evaluated at four minutes after rest. The patients in exercise group performed ergometer exercise with 40% to 60% of the load for 10 minutes. TS and CPM were re-evaluated after the exercise and fNIRS and GSR were measured during the exercise session. NRS, PCS and HADS were re-evaluated after the completed the exercise session. The patients in control group kept resting position (sitting) for 10 minutes and they did not performed any exercises. Comparisons between the two groups were analyzed by using SPSS (version 22, Co IBM).
Results: There were no significant differences in baseline between the two groups. NRS and PCS were significant improved (p .05) and CPM and TS were significant stimulated (p .05) in the exercise group. The activity of the right dorsolateral prefrontal cortex was also significantly increased in the exercise group (p = .04), when the descending pain inhibitory system was activated. There was a tendency to decrease the activity of the limbic system in the exercise group, although the differences was not significant between the two groups.
Conclusion(s): The results of this study considered that ergometer exercise stimulated the descending pain inhibitory system and suppressed the sensitization of pain by increasing the activity of the dorsolateral prefrontal cortex. Furthermore, activation of the dorsolateral prefrontal cortex inhibited the activity of the limbic system. The activation of the descending pain inhibitory system decreased the impulse of pain from the dorsal horn of the spinal cord and decreased the transmission of the pain stimulus to the brain. NRS which is a sensory factor of pain and PCS were then improved. Thus, ergometer exercise is effective for decreasing the intensity of chronic pain.
Implications: The exercise using combination with medication can develop more effective treatment for chronic pain. The further study should examine the effects of combination with medication by evaluating the neurophysiological mechanism of pain.
Keywords: chronic pain, neurophysiological mechanism of pain, exercise therapy
Funding acknowledgements: This study was not subsidized.
Purpose: The aim of this study was to clarify the effects of exercise on the neurophysiological mechanism of pain.
Methods: Cross-sectional study was utilized. Thirty patients with chronic pain lasting over six months were recruited from pain clinic in Hamamatsu city Japan and divided into two groups (exercise group (n=15) and control group (n=15)). All participants were under medication. Firstly, numerical Rating Scale (NRS), Pain Catastrophizing Scale (PCS), Hospital Anxiety, Depression Scale (HADS) and determined pressure pain thresholds (PPTs) were measured in both groups. Functional near infrared spectroscopy (fNIRS) and galvanic skin response (GSR) were then attached at the resting position. Temporal summation (TS) and conditioned pain modulation (CPM) were evaluated at four minutes after rest. The patients in exercise group performed ergometer exercise with 40% to 60% of the load for 10 minutes. TS and CPM were re-evaluated after the exercise and fNIRS and GSR were measured during the exercise session. NRS, PCS and HADS were re-evaluated after the completed the exercise session. The patients in control group kept resting position (sitting) for 10 minutes and they did not performed any exercises. Comparisons between the two groups were analyzed by using SPSS (version 22, Co IBM).
Results: There were no significant differences in baseline between the two groups. NRS and PCS were significant improved (p .05) and CPM and TS were significant stimulated (p .05) in the exercise group. The activity of the right dorsolateral prefrontal cortex was also significantly increased in the exercise group (p = .04), when the descending pain inhibitory system was activated. There was a tendency to decrease the activity of the limbic system in the exercise group, although the differences was not significant between the two groups.
Conclusion(s): The results of this study considered that ergometer exercise stimulated the descending pain inhibitory system and suppressed the sensitization of pain by increasing the activity of the dorsolateral prefrontal cortex. Furthermore, activation of the dorsolateral prefrontal cortex inhibited the activity of the limbic system. The activation of the descending pain inhibitory system decreased the impulse of pain from the dorsal horn of the spinal cord and decreased the transmission of the pain stimulus to the brain. NRS which is a sensory factor of pain and PCS were then improved. Thus, ergometer exercise is effective for decreasing the intensity of chronic pain.
Implications: The exercise using combination with medication can develop more effective treatment for chronic pain. The further study should examine the effects of combination with medication by evaluating the neurophysiological mechanism of pain.
Keywords: chronic pain, neurophysiological mechanism of pain, exercise therapy
Funding acknowledgements: This study was not subsidized.
Topic: Pain & pain management
Ethics approval required: Yes
Institution: Seirei Christopher University
Ethics committee: Seirei Christopher University Ethics Committee
Ethics number: 17086
All authors, affiliations and abstracts have been published as submitted.
