It’s always an exciting thing when we see a new study emerge from the research rockstars at the New Zealand College of Chiropractic, and even more so when the study in question impacts directly on a burgeoning area of interest for us here at the Australian Spinal Research Foundation – that is quality of life and functional outcome measures beyond pain alone.
Quality of life is increasingly being measured in chiropractic settings using specific questionnaires based on a growing understanding that the way chiropractic impacts a person’s ability to engage with life matters greatly to them. Therefore it matters to us. How do we take this conversation forward in the evidence bank? Case reports make up a big part of it, of course. But when we see larger studies, like the latest from Dr Heidi Haavik and team, it is an exciting moment indeed.
This latest study combines brain changes – that is, neuroplastic responses – to chiropractic care and how this might impact pain, mood, sleep and quality of life. But this time, the study showed exciting possibilities in terms of very specific brain networks that are also involved in emotion, behaviour, and whole-body perception. This could potentially be the first major study showing how chiropractic philosophy about things like human consciousness may meet specific neuroscience. This could not be more exciting for the chiropractic tribe.
What did the study do?
In this groundbreaking study, the team took 76 people with non-specific chronic low back pain (CLBP) and divided them (randomly) into two groups. One group received 4-weeks of usual care (the control group) and the other received 4-weeks of chiropractic in addition to their usual care (the intervention group).
In both groups, EEG data was recorded before, immediately after the first session, and at the end of the four weeks. The PROMIS-29 (a patient-reported quality of life assessment) was completed before and after the four weeks of care. Additionally, information on sleep quality and physical activity was recorded continuously via Fitbit watches – thus capturing data from an emerging field of wearable health monitors.
For the group that received chiropractic care, their treatment included manual high-velocity low-amplitude (HVLA) adjustments to the spine or pelvic joints that were identified as subluxated.
Usual care included any care recommended or prescribed by non-chiropractic health providers for CLBP. This included things like self-management advice, pharmacologic pain management, physical therapy, or referral to a pain clinic.
What did the data show?
While EEG data showed a significant increase in Theta, Alpha, and Beta power and a decrease in Delta power, these changes weren’t strong enough to rise to the level of statistical significance. Changes in the N30 amplitude did, though. They decreased immediately after chiropractic care, and further decreased post 4 weeks of chiropractic care. Interestingly, there were no changes were observed in the control group.
This is a significant finding, given that this particular brain impulse is in response to somatosensory evoked potentials, or electrical signals in the brain in response to stimuli. The N30 commonly increases in response to abnormal excitatory stimuli, such as disorders of the basal ganglia, which drives motor control. How this specific finding relates to subluxation could become very important in time.
The study also found an overall improvement in quality of life in the chiropractic care group. Specifically, chiropractic care had a significant effect on the assessment in the areas of anxiety, depression, fatigue, pain intensity, and pain interference. Fitbit data showed an increase in the light sleep stage in the chiropractic care group.
With all these factors combined, there are many potential rabbit holes to dive down in terms of potential research. Depression and anxiety are two factors that drive an immense amount of public health concern all by themselves, let alone pain intensity, pain interference, sleep and fatigue. But this study leads the researchers to some very specific findings regarding specific brain networks, which potentially have profound impacts from chiropractic care.
Previous research had identified changes within the DMN (default mode network) in patients with chronic stroke receiving chiropractic care. [1] The previous study reported an increase in functional connectivity between different regions within the DMN. This current study shows that these changes are also found in ‘regular’ chiropractic patients and aren’t limited to stroke patients. This is significant indeed. Why? The authors of the study describe it best in the following excerpt:
“The DMN is active when one engages in self-reflection, mind-wandering, daydreaming, recall of personal experiences, reflection of social interactions and envisaging the future. Chronic problems, such as chronic musculoskeletal pain, as well as common chronic disorders such as anxiety and depression have been found to have clear deficits in access, engagement and disengagement of the DMN. Not only have such disorders shown changes within the DMN, but also between the DMN and other networks including various sensory networks, pain networks, the salience network and the fronto-parietal (goal oriented) networks. The changes within the DMN and between the DMN and other networks provide a neuro-biological explanation for why these problems (e.g., pain, anxiety and depression) become embodied, i.e., they become an integral part of the persons sense of self, making treatment difficult.
It is thought that when suffering is ongoing long-term the feelings of pain may become part of one’s internal self-story, and, similarly, ongoing worry can develop into anxiety and ongoing sadness can become depression. It is, therefore, fascinating to see that chiropractic care can alter functional connectivity within the DMN in a manner that coincides with improvements in pain, depression, anxiety, fatigue and sleep. It is likely that the functional connectivity changes found within the DMN in the current study between the pre-intervention recording and post 4 weeks of chiropractic care reflects a difference in how the study participants were reflecting on themselves and their everyday experiences over time. The participants appear to be altering their constructed sense of self and how they understand their own mental states over the four weeks of care. At the end of the 4 weeks of chiropractic care, these participants reported significantly less depressive, anxious and pain symptoms. Thus, their self-reflection after 4 weeks of care appears now to be more positive, since they also reported experiencing less pain, less fatigue, less anxiety and less depression and improved sleep.”
Chiropractic philosophers have been talking about how chiropractic might impact consciousness for years. This study offers up the first insight as to how this might happen on a brain-wave level.
The complex relationship between pain pathology, pain habits in the brain, and the way a person’s physiology and mental health adapt is something that is likely to take up space in research and health practice for a long time to come. Therefore, having some chiropractic specific insight into this is profoundly valuable both for chiropractors and the people they care for.
In addition to this, other research pertaining to specific brain wave bands highlighted in this study could point to significant findings for chiropractic in the future, even though they didn’t rise to the level of statistical significance in this one. Specifically:
- Alpha rhythms are known to be important in perceiving what is around us and is typically lower in individuals with chronic pain. The changes in Alpha power recorded in the current study may reflect the change in pain perception in chiropractic patients.
- The specific areas in which changes in brain activity were recorded, ParaH and rostral ACC, are areas known to be involved in the descending pain inhibitory pathway, a pathway that is malfunctional in chronic pain patients and potentially involved in the transition of pain from acute to chronic. Chiropractic care’s potential to affect these areas of the brain and descending pathways may explain why it is clinically effective for both acute and chronic forms of low back pain and is a well-known and recommended option for managing these conditions.
- This study adds to the growing number of papers outlining how chiropractic care may change the way the brain functions and integrates information.
- Improvements in sleep and quality of life following chiropractic care are well documented across controlled studies and case reports.
Researchers remarked that “The contemporary model of the vertebral subluxation suggest that a vertebral subluxation can lead to abnormal multisensory processing and filtering of interoceptive and exteroceptive stimuli that can ultimately lead to poor motor control of the vertebral column as well as other muscles in the body. The results from the current study support this contemporary model and suggest that chiropractic care provided to the study participants has altered the way their brains integrate both interoceptive and exteroceptive sensory information in a multimodal fashion, including the consideration of past memories and future expectations, that have resulted in an altered narrative sense of self (i.e., altered DMN function).”
As is often true, a robust study like this gives us some insights into the power of chiropractic, but leaves us with many more lines of investigation to go down – some to confirm and repeat conclusions such as those in this study, and some to take us to new frontiers.
This profound paper is essentially showing us that chiropractic care may have the potential to alter our whole experience of life and pain, by activating the DMN, thus allowing us to update our body awareness schemas and change the way we interact with pain and symptoms on a physical and emotional level. It may enable us to improve whole-body perception, emotional control, and body functions. In this study, it showed up as less pain intensity, anxiety, depression and more light sleep and energy.
There could be much more to come.
This is massive. There is so much yet to discover, and so much one blog article can’t cover in terms of this fantastic paper. You’ll really have to read it yourself. We can’t wait to see what else comes out from the team at NZCC.
Current study reference: Haavik, H., Niazi, I.K., Amjad, I., Kumari, N., Ghani, U., Ashfaque, M., Rashid, U., Navid, M.S., Kamavuako, E.N., Pujari, A.N., et al. Neuroplastic Responses to Chiropractic Care: Broad Impacts on Pain, Mood, Sleep, and Quality of Life. Brain Sci. 2024, 14, 1124.
- Steven Waterstone, T., Niazi, I.K., Navid, M.S., Amjad, I., Shafique, M., Holt, K., Haavik, H., Samani, A. Functional Connectivity Analysis on Resting-State Electroencephalography Signals Following Chiropractic Spinal Manipulation in Stroke Patients. Brain Sci. 2020, 10, 644.
