Glucose Metabolic Changes in the Brain and Muscles of Patients with Nonspecific Neck Pain Treated by Spinal Manipulation Therapy

Glucose Metabolic Changes in the Brain and Muscles of Patients with Nonspecific Neck Pain Treated by Spinal Manipulation Therapy:

A [18F] FDG PET Study {a radioactive glucose PET scan study}. Evidence-Based Complementary and Alternative Medicine Volume 2017

 The study has four important findings:

  • The brain is affected by chiropractic adjusting
  • Chiropractic adjusting inhibits pain
  • Chiropractic adjusting inhibits muscle tone, improving ranges of motion
  • Chiropractic adjusting inhibits sympathetic tone, a key influence on immunity and other factors in systemic wellness


PET (positron emission tomography) scan is a powerful neuroimaging technique to investigate neuronal activity in the human brain and muscles.

18F-labeled fluorodeoxyglucose (FDG) is a radioactive analogue of glucose, and is an excellent imaging marker of brain glucose consumption (brain metabolic activity).


A PET scan can visualize brain metabolic changes induced by spinal manipulative therapy (SMT). The aim of this study was to investigate changes in brain and muscle glucose metabolism using positron emission tomography with fluorodeoxyglucose.


Twenty-one male volunteers were recruited for the present study. Spinal manipulative therapy (SMT) was applied using an Activator in accordance with the Activator Methods protocols. The Activator applied impulses to specific vertebrae or joints. “SMT was performed on the subject in a prone position without movements such as cervical rotation, lateral flexion, and extension, in order to prevent the muscular FDG uptake due to muscle contractions during the therapeutic procedure. SMT was carried out on the whole spine, the scapulae, the ilium, and the sacrum, as necessary for each subject. The mean number of SMT adjusted sites was 8 per subject.”


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.” “SMT on all subjects was performed by the same Chiropractor, who was an advanced practitioner of Activator Methods.”


 1) Spinal manipulation therapy (SMT) has “been applied mainly to musculoskeletal problems such as neck pain or low back pain.”

2) Previous studies have shown that “SMT has beneficial clinical effects, including pain relief and reduction of blood pressure.”

3) “The intensity of subjective pain was evaluated using a 0–10 visual analog scale (VAS) before and after SMT in the treatment condition.”

4) “Cervical muscle tension was measured bilaterally at the superior part of the trapezius muscle using a tissue hardness meter.”

5) “Salivary amylase levels were measured for each subject using an amylase monitor to evaluate changes in autonomic nervous system (ANS) function.”

6) “Salivary 𝛼-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.”

7) “We observed multiple changes in brain activity after SMT.”

8) “The findings of the present study demonstrate how stimuli to the mechanoreceptors of the joints and skin during SMT are processed in the brain.”

9) “Brain processing after SMT may lead to physiological relaxation via a decrease in sympathetic nerve activity.” [Key Point]

10) “Comparisons of VAS pain scores in the treatment condition revealed a significant decrease after SMT.”

11) “Cervical muscle tension was significantly reduced bilaterally after SMT.” “Our results suggest that stimulation of joints during SMT induced relaxation of reflexive muscle tension.”

12) “Salivary amylase level decreased significantly after SMT.”

Changes Following Spinal Manipulation

-Visual Analogue Pain, VAS, Significantly Reduced By About 65%

-Muscle Tension Significantly Reduced

-Salivary Amylase (as an indicator of norepinephrine sympathetic tone)Significantly Reduced

-Cingulate Cortex (part of the limbic system)emotions, learning, memory

-Increased Cerebellar Vermis (spinal proprioception)posture/movement, emotions Increased

-Somatosensory Cortex (pain perception/localization)Reduced

-Prefrontal Cortex (executive function) personality, planning, decision making, moderating social behavior Reduced

13) The Cerebellar Vermis:

  • “The Cerebellar Vermis receives somatic sensory information from the spinal cord and via the vestibulospinal tract or reticular nuclei of the brainstem through the spinal cord, connecting indirectly or directly with motor cells on the ventral horn. These systems control involuntary muscular tension and reflexes.”
  • The cerebellum has many roles in non-motor functions.
  • “The cerebellum is also thought to have a functional role as an integrator of multiple effector systems, including affective processing, pain modulation, and sensorimotor processing.”
  • The Cerebellar Vermis is activated during mental recall of emotional personal episodes in humans. 14) “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.”[Key Point]

14) SMT stimuli to the joints may result in “decreased sympathetic nerve activity.” [Key Point]

15) These authors believe that the relaxation of muscle tone documented in this study occur as a consequence of two mechanisms:

  • Inhibition of sympathetic autonomic nervous activity
  • Improvement of the range of joint movement

16) “We observed that SMT stimulus induced physical responses such as muscle tension relaxation, pain relief, and reduced amylase secretion.”

17) “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. “

18) “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”).

20) “The brain response to SMT may reflect the psychophysiological relaxation that accompanies reduced sympathetic nerve activity.”


This study used the most sophisticated technology to date to assess the affects of chiropractic spinal adjusting:

  • Changes in radioactive glucose metabolism as measured with a PET scan in both the brain and in muscles
  • Changes in muscle tone
  • Improvement in pain using a VAS
  • Changes in sympathetic nervous system production and release of norepinephrine (sympathetic tone)


Akie Inami, Takeshi Ogura, Shoichi Watanuki, Mehedi Masud, Katsuhiko Shibuya,Masayasu Miyake, Rin Matsuda, Kotaro Hiraoka, Masatoshi Itoh, Arlan W. Fuhr,Kazuhiko Yanai, Manabu Tashiro:Takeshi Ogura is a chiropractor.Arlan Fuhr is a chiropractor and owner of Activator Methods International, Ltd.

This study was done at Tohoku University Graduate School of Medicine, Sendai, Japan, along with the Division of Cyclotron Nuclear Medicine at Tohoku University. This article has 47 references.




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