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 some articles that conclude that changes in brain function occurred as a result of a chiropractic manipulation/adjustment.
1. Holt K, et al. The effects of a single session of chiropractic care on strength, cortical drive, and spinal excitability in stroke patients. Scientific Reports, 9, Article number: 2673. 2019.
The objective of this study was to investigate whether a single session of chiropractic care could increase strength in weak plantar flexor muscles in chronic stroke patients. Maximum voluntary contractions (strength) of the plantar flexors, soleus evoked V-waves (cortical drive), and H-reflexes were recorded in 12 chronic stroke patients, with plantar flexor muscle weakness, using a randomized controlled crossover design. Plantar flexor muscle strength increased in chronic stroke patients after a single session of chiropractic care. An increase in V-wave amplitude combined with no significant changes in H-reflex parameters suggests this increased strength is likely modulated at a supraspinal level.
- Ogura T, et al. Cerebral metabolic changes in men after
chiropractic spinal manipulation for neck pain. Alternative
Therapies. 17(6). 2011.
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.
- 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).
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.
- Lelic D, et al. Manipulation of dysfunctional spinal joints
affects sensorimotor integration in the prefrontal cortex: a brain source
localization study. Neural Plasticity. 2016.
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.
- Carrick FR. Changes in brain
function after manipulation of the cervical spine. Journal of
Manipulative & Physiological Therapeutics. 20(8). 1997.
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.
- 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.