Over the past 2 decades, there has been a growing body of evidence to suggest that neural plastic changes take place following chiropractic spinal manipulation/adjustments. Here are 5 articles that conclude that changes in brain function occurred as a result of a chiropractic manipulation/adjustment.
Chiropractic was hypothesized to induce metabolic increase or decrease (activation or deactivation) in specific areas of the brain. PET scan analysis showed increased glucose metabolism in the inferior prefrontal cortex (BA47), anterior cingulate cortex (BA 32), and middle temporal gyrus (BA21), while decrease metabolism was observed in the cerebellar vermis and visual association cortex. These brain changes from the Chiropractic manipulation/adjustments resulted in a relaxation in the sympathetic system, reduced muscle tone, and decreased pain intensity.
2. Gay CW, et al. Immediate changes after manual therapy in resting-state functional connectivity as measured by fmri in participants with induced low back pain. Journal of Manipulative and Physiological Therapeutics. 37(9). 2014.
The purpose of this study was to use fMRI to investigate the immediate changes in functional connectivity (FC) between brain regions after Chiropractic manipulation/adjustments, spinal mobilization (grade 3), and therapeutic touch (light pressure). With all of the manual therapies, there were changes in connections between the left posterior cingulate cortex and the left anterior insular cortex, the left posterior insular cortex and periaquedactal grey, and the left primary sensory cortex and right posterior insular cortex. The results suggest that neurophysiologic changes after manual therapy may be an underlying mechanism of pain relief.
Investigators utilizing techniques such as transcranial magnetic stimulation and somatosensory evoked electroencephalographic (EEG) potentials have suggested that neuroplastic brain changes occur in structures such as the primary sensory cortex, primary motor cortex, prefrontal cortex, basal ganglia, and cerebellum. Electrodiagnsotic testing showed after a single session of spinal manipulation of dysfunctional segments in subclinical pain patients alters somatosensory processing at the cortical level, particularly within the prefrontal cortex.
The purpose of this study was to investigate whether chiropractic manipulation/adjustment to the neck was associated with changes in brain function. This study used visual blind spot maps to measure pre and post outcomes, and showed changes in these visual fields after a chiropractic manipulation/adjustment as a presumed consequence of changes in brain function.
5. Daubeny N, et al. Effects of contralateral extremity manipulation on brain function. International journal on Disability and Human Development. 9(4). 2010.
Previous studies have shown that the visual blind spot changes after a chiropractic manipulation/adjustment as well as acupuncture. This study investigated the effect manipulating/adjusting an upper extremity joint has on the visual blind spot as a presumed result of changes in brain function. This study showed that after manipulation/adjustment of the upper extremity, there are changes in visual blind spots, presumably from changes in brain function.