Glucose Metabolic Changes in the Brain after Spinal Manipulation

This week from Dr. Cerami and Utah Sports and Wellness

From: Evidence-Based Complementary and Alternative Medicine, 2017

 

Quick Summary:

This study was conducted using the most sophisticated technology to date, to assess the effects of chiropractic adjusting. Spinal manipulative therapy (SMT) was applied using an Activator in accordance with the Activator Methods protocols. “The intensity of subjective pain was evaluated using a 0–10 visual analog scale (VAS) before and after SMT in the treatment condition. Glucose metabolism of the brain and skeletal muscles was measured. Also measured was salivary amylase levels as an index of autonomic nervous system (ANS) activity, muscle tension, and subjective pain intensity. “Other measurements indicated relaxation of cervical muscle tension, decrease in salivary amylase level (suppression of sympathetic nerve activity), and pain relief after SMT.” Multiple changes were observed in brain activity after SMT The findings of the present study demonstrate how stimuli to the mechanoreceptors of the joints and skin during SMT are processed in the brain. Brain processing after SMT may lead to physiological relaxation via a decrease in sympathetic nerve activity. Comparisons of VAS pain scores in the treatment condition revealed a significant decrease after SMT. Cervical muscle tension was significantly reduced bilaterally after SMT. Our results suggest that stimulation of joints during SMT induced relaxation of reflexive muscle tension. Salivary amylase level decreased significantly after SMT. “Our assessment of body responses in this study showed relaxation of muscle tension and decreased salivary amylase levels—phenomena that are associated with reduced sympathetic nerve activity.”

Abstract:

The aim of this study was to investigate changes in brain and muscle glucose metabolism that are not yet known, using positron emission tomography with [18F]fluorodeoxyglucose ([18F]FDG PET). Methods. Twenty-one male volunteers were recruited for the present study. [18F]FDG PET scanning was performed twice on each subject: once after the spinal manipulation therapy (SMT) intervention (treatment condition) and once after resting (control condition). We performed the SMT intervention using an adjustment device. Glucose metabolism of the brain and skeletal muscles was measured and compared between the two conditions. In addition, we measured salivary amylase level as an index of autonomic nervous system (ANS) activity, as well as muscle tension and subjective pain intensity in each subject. Results. Changes in brain activity after SMT included activation of the dorsal anterior cingulate cortex, cerebellar vermis, and somatosensory association cortex and deactivation of the prefrontal cortex and temporal sites. Glucose uptake in skeletal muscles showed a trend toward decreased metabolism after SMT, although the difference was not significant. Other measurements indicated relaxation of cervical muscle tension, decrease in salivary amylase level (suppression of sympathetic nerve activity), and pain relief after SMT. Conclusion. Brain processing after SMT may lead to physiological relaxation via a decrease in sympathetic nerve activity.

These authors also note:

  • Spinal manipulation therapy (SMT) has “been applied mainly to musculoskeletal problems such as neck pain or low back pain.”
  • Previous studies have show that “SMT has beneficial clinical effects, including pain relief and reduction of blood pressure.”
  • “The intensity of subjective pain was evaluated using a 0–10 visual analog scale (VAS) before and after SMT in the treatment condition.”
  • “Cervical muscle tension was measured bilaterally at the superior part of the trapezius muscle using a tissue hardness meter.”
  • “Salivary amylase levels were measured for each subject using an amylase monitor to evaluate changes in autonomic nervous system (ANS) function.”
  • “Salivary -amylase levels correspond to plasma norepinephrine levels and are utilized as an accessible measure of sympathetic nervous reactivity in stress research, with lower levels indicating lower activity.”
  • We observed multiple changes in brain activity after SMT.”
  • “The findings of the present study demonstrate how stimuli to the mechanoreceptors of the joints and skin during SMT are processed in the brain.”
  • “Brain processing after SMT may lead to physiological relaxation via a decrease in sympathetic nerve activity.”
  • “Comparisons of VAS pain scores in the treatment condition revealed a significant decrease after SMT.”
  • “Cervical muscle tension was significantly reduced bilaterally after SMT.” “Our
    results suggest that stimulation of joints during SMT induced relaxation of reflexive muscle tension.”
  • “Salivary amylase level decreased significantly after SMT.”
  •  SMT stimuli to the joints may result in “decreased sympathetic nerve activity.”
  •  These authors believe that the relaxation of muscle tone documented in this study occur as a consequence of two mechanism:
    • Inhibition of sympathetic autonomic nervous activity
    • “Improvement of the range of joint movement.”
  • “We observed that SMT stimulus induced physical responses such as muscle tension relaxation, pain relief, and reduced amylase secretion.”
  • “Neural inputs evoked by SMT stimuli via various receptors in muscles, tendons, and joints may ascend to the somatosensory areas of the brain through the medial lemniscal system. “
  • “In summary, we observed metabolic changes in the brain and skeletal muscles, as well as reductions in subjective pain, muscle tension, and salivary amylase, after SMT intervention.
  • These results may be associated with reduced sympathetic nerve activity,” suggesting that SMT induces sympathetic inhibition (“relaxation”).
  • “The brain response to SMT may reflect the psychophysiological relaxation that accompanies reduced sympathetic nerve activity.”
2018-10-01T21:54:50+00:00October 1st, 2018|