As a chiropractor in Ashland, Oregon, I’m always striving to stay on top of the latest research to better understand and care for my patients dealing with various health challenges. A fascinating recent review article has shed new light on the potential causes and connections between post-concussion syndrome and other conditions involving persistent neurological symptoms (Rathbone et al., 2015).

What is Post-Concussion Syndrome?

Post-concussion syndrome (PCS) refers to a collection of symptoms that commonly occur together and persist after a concussion or mild traumatic brain injury. The symptoms can include headaches, dizziness, fatigue, irritability, anxiety, insomnia, and difficulties with concentration and memory (American Psychiatric Association, 2013).

While the current diagnostic criteria for PCS focuses on these symptoms occurring after head trauma, research has uncovered some interesting findings that call into question whether PCS is truly unique to brain injuries. Studies have found that non-head injured patients, such as those with whiplash injuries or even healthy controls, frequently report nearly identical symptom clusters to PCS (Meares et al., 2008; Meares et al., 2011).

This has led researchers to explore what other factors beyond direct brain trauma could be contributing to PCS-like conditions. And mounting evidence is pointing towards one common underlying culprit: inflammation.

The Inflammation Connection

Inflammation is the immune system’s natural response to injury or infection. In the short-term, it is a necessary part of the healing process. However, when inflammation becomes chronic or excessive, it can lead to dysfunction and damage.

For some time, animal studies have demonstrated that brain injuries, even mild ones, trigger inflammatory responses in the brain involving immune cells called microglia and inflammatory molecules called cytokines. These neuroinflammatory changes correlate with the development of cognitive, emotional, and behavioral symptoms – many of which overlap with the symptoms of PCS (Rathbone et al., 2015).

Interestingly though, it’s not just brain injuries that can provoke neuroinflammation and these associated symptoms. Systemic inflammation in the body, as occurs with infections, surgeries, or major injuries to areas other than the head, has also been shown to induce inflammatory responses in the brain and lead to PCS-like effects (Rathbone et al., 2015).

In humans, elevated levels of inflammatory markers in the blood and cerebrospinal fluid have been associated with worse outcomes and persistent neurological symptoms after brain injuries as well as critical illnesses, infections, and surgeries (Rathbone et al., 2015). Giving inflammatory-stimulating substances to healthy people even triggers PCS symptoms like headaches, fatigue, depression and cognitive deficits (Rathbone et al., 2015).

From PCS to PIBS

Based on this wealth of evidence linking inflammation in the brain to the symptoms seen in PCS and other related conditions, the authors of this review propose a new unifying framework: post-inflammatory brain syndromes (PIBS) (Rathbone et al., 2015).

The PIBS concept suggests that any significant inflammatory insult, whether it originates in the brain (like with a concussion) or elsewhere in the body, has the potential to trigger a cascade of neuroinflammation that alters brain function and generates the common symptom clusters we associate with PCS (Rathbone et al., 2015).

Other conditions that could fall under the PIBS umbrella include post-operative cognitive dysfunction, chemo-brain, post-ICU syndrome, chronic fatigue syndrome, and Gulf War Illness, among others (Rathbone et al., 2015). By recognizing the shared inflammatory mechanisms behind these conditions, we may open new doors for understanding their etiologies and developing targeted therapies.

Implications for Diagnosis and Treatment

Adopting a PIBS perspective could have significant implications for how we diagnose and treat conditions like PCS. Rather than viewing them as isolated syndromes, clinicians may need to broaden their differential and consider the possibility of systemic inflammatory triggers, even in the absence of a known brain insult.

Diagnostic tools looking for signs of neuroinflammation, such as PET imaging or inflammatory biomarkers in the blood and CSF, may prove useful for identifying PIBS (Rathbone et al., 2015). And interventions aimed at reducing neuroinflammation and supporting the brain’s resilience in the face of inflammatory insults could represent promising avenues for managing or even preventing these conditions.

Some early evidence suggests that nutritional and lifestyle approaches that reduce inflammation, such as omega-3 fatty acids and healthy sleep, as well as certain medications that inhibit inflammatory pathways, may help improve chronic neurological symptoms (Rathbone et al., 2015). More research is certainly needed, but this is an exciting area to watch.

Conclusions

As research continues to unravel the complexities of PCS and related conditions, the importance of inflammation as a common thread is becoming increasingly apparent. By shifting our framework to one of post-inflammatory brain syndromes, we may be able to better identify those at risk, implement preventative strategies, and develop targeted treatments to improve outcomes for the many individuals struggling with these debilitating symptoms.

As a healthcare provider, staying abreast of these evolving concepts helps me deliver the most up-to-date and comprehensive care for my patients. If you are dealing with persistent neurological symptoms after a concussion or other inflammatory event, please don’t hesitate to reach out. Together we can explore personalized strategies to support your brain health and overall resilience.

References:

American Psychiatric Association. (2013). Diagnostic and statistical manual of mental disorders (5th ed.). https://doi.org/10.1176/appi.books.9780890425596

Meares, S., Shores, E. A., Taylor, A. J., Batchelor, J., Bryant, R. A., Baguley, I. J., Chapman, J., Gurka, J., Dawson, K., Capon, L., & Marosszeky, J. E. (2008). Mild traumatic brain injury does not predict acute postconcussion syndrome. Journal of Neurology, Neurosurgery & Psychiatry, 79(3), 300-306. https://doi.org/10.1136/jnnp.2007.126565

Meares, S., Shores, E. A., Taylor, A. J., Batchelor, J., Bryant, R. A., Baguley, I. J., Chapman, J., Gurka, J., & Marosszeky, J. E. (2011). The prospective course of postconcussion syndrome: the role of mild traumatic brain injury. Neuropsychology, 25(4), 454-465. https://doi.org/10.1037/a0022580

Rathbone, A. T. L., Tharmaradinam, S., Jiang, S., Rathbone, M. P., & Kumbhare, D. A. (2015). A review of the neuro- and systemic inflammatory responses in post concussion symptoms: Introduction of the “post-inflammatory brain syndrome” PIBS. Brain, Behavior, and Immunity, 46, 1-16. https://doi.org/10.1016/j.bbi.2015.02.009