The Hidden Battle of Post-Concussion Syndrome – What You Need to Know

Introduction

Post-concussion syndrome (PCS) is a complex neurological condition with ongoing symptoms following mild traumatic brain injury (mTBI). Symptoms include headaches, dizziness, cognitive impairments, and emotional issues, often lasting beyond the expected recovery time. Patients face physical symptoms, psychological challenges, and cognitive difficulties, with sensory hypersensitivity further complicating daily life.

Recent research underscores the need to consider PCS from biological, psychological, and social perspectives, recognizing the impact of pre-existing conditions like anxiety disorders or ADHD on symptoms and treatment. This article reviews current research on diagnosing and treating PCS, covering both traditional methods and new therapies.

The Multidimensional Nature of PCS

The complexity of post-concussion syndrome (PCS) arises from significant individual variability in response to mild traumatic brain injury (mTBI) and the diverse factors contributing to symptom persistence. Polinder et al. (2018) conducted an extensive review that elucidates the underlying mechanisms of PCS, underscoring the importance of adopting multidimensional diagnostic and treatment frameworks. Their research indicates that PCS symptoms result from intricate interactions between biological mechanisms, psychological factors, and social contexts. Pre-existing mental health conditions, particularly depression and anxiety, often exacerbate PCS symptoms, while social support networks and individual personality traits markedly influence recovery trajectories (Polinder et al., 2018).

Diagnostic challenges arise from inconsistent criteria across classification systems, particularly between DSM-5 TR and ICD-11, leading to varying prevalence estimates and hindering treatment standardization. Conventional neuroimaging techniques, such as CT and MRI, often miss the microscopic changes linked to PCS. While advanced methods like diffusion tensor imaging (DTI) and functional MRI (fMRI) show potential in detecting these subtle abnormalities, their clinical application is limited. Establishing unified diagnostic frameworks and incorporating advanced imaging technologies is crucial for enhancing patient outcomes and progressing the field (Polinder et al., 2018).

Psychological and Cognitive Dimensions

Persistent post-concussion syndrome (PCS) symptoms frequently encompass psychological and cognitive issues such as depression, anxiety, irritability, memory deficits, attentional problems, challenges in emotion regulation, and symptoms resembling attention deficit hyperactivity disorder (ADHD). Rao et al. (2017) conducted an analysis of concussion's neuropsychiatric effects, noting that while some symptoms resolve independently, others may persist for extended periods. They recommend a multifaceted approach incorporating psychoeducation, cognitive behavioral therapy (CBT), and supportive interventions to effectively address these issues.

Emotion regulation difficulties related to PCS often present as heightened emotional reactivity, decreased frustration tolerance, and impaired stress management, which can exacerbate anxiety and irritability. Interventions like mindfulness-based stress reduction and emotion-focused therapy are effective in enhancing emotional stability and resilience. The symptom overlaps between PCS and ADHD complicates diagnosis, necessitating careful evaluation to distinguish between PCS and pre-existing ADHD. The biopsychosocial model is particularly valuable in these cases, as it emphasizes both physiological and psychological factors to formulate comprehensive treatment strategies.

Sensory Processing Disruption in PCS

Alterations in sensory processing are a significant aspect of post-concussion syndrome that is often overlooked. Research by Meylakh and Henderson (2022) on altered sensory pathways in migraine offers insights relevant to PCS, due to the considerable symptom overlap between these conditions. Their study identified "increased infra-slow oscillatory activity in visual cortices" and "increased functional connectivity between visual cortices and other sensory regions" in individuals with sensory hypersensitivity. This heightened cross-modal sensory coupling accounts for why PCS patients frequently report stimulation in one sensory modality (e.g., bright lights) triggering symptoms across multiple domains (e.g., headache, nausea, cognitive fog) (Meylakh & Henderson, 2022).

Maher and Flint Rehab (2021) refer to this phenomenon as "sensory defensiveness," which arises from neural instability following brain injury. They describe that damage to the "sensory processing centers in the brain leads to hypersensitivity," with the brain directing energy toward healing, making it "less resilient to external stimuli." Consequently, stimuli that were previously manageable, such as background conversations, fluorescent lighting, or routine touch can become overwhelming triggers for symptom exacerbation (Maher & Flint Rehab, 2021).

The biomechanical impact of concussion on sensory-motor integration has been further clarified by Chiu et al. (2013), who found that "concussions disrupt motor control and coordination beyond simple balance impairments." Their research indicated "increased knee-ankle coordination variability during the swing phase" of gait, particularly when subjects encountered dual-task demands or obstacles. This finding elucidates why many PCS patients have difficulty in complex sensory environments requiring simultaneous cognitive and motor processing, such as navigating crowded spaces or maintaining conversations while walking (Chiu et al., 2013).

Managing Sensory Overload in PCS

Considering the substantial impact of sensory processing disruptions on daily functioning and recovery, it is crucial to implement structured approaches to sensory management for PCS patients. Webster (2011) recommends developing personalized "sensory diets," which are scheduled activities designed to provide appropriate sensory input to aid in regulating the nervous system.

Therapy Type	Description
Deep pressure therapy	Weighted blankets or compression garments, which can calm an overactive nervous system
Vestibular activities	Gentle rocking or slow walking to recalibrate balance systems
Proprioceptive input	Resistance exercises or joint compression to improve body awareness
Controlled sensory exposure	Gradually rebuild tolerance to challenging stimuli

To manage specific sensory challenges, Maher and Flint Rehab (2021) suggest practical strategies such as using earplugs or noise-canceling headphones to address auditory sensitivity, wearing sunglasses indoors or yellow-tinted glasses to mitigate visual hypersensitivity, and incorporating short naps and quiet breaks to regulate overall sensory load. They emphasize the importance of planning and preparation to minimize unexpected sensory challenges, recommending actions like avoiding peak hours in crowded places and establishing clear boundaries and safe words with family members to indicate when overstimulation is occurring (Maher & Flint Rehab, 2021).

Graded exposure therapy is another evidence-based approach for addressing sensory defensiveness. This method involves systematic, controlled exposure to challenging sensory stimuli, starting with low-intensity environments and gradually progressing to more stimulating spaces as tolerance improves. This process aids in recalibrating the brain's response to sensory input, potentially reversing some of the neural instability that underlies PCS symptoms (Maher & Flint Rehab, 2021).

Neurophysiological Mechanisms of PCS

Recent research has significantly enhanced our understanding of the neural mechanisms underlying persistent post-concussion symptoms (PCS). A significant finding involves disruptions to dopaminergic systems following traumatic brain injury (TBI). Jenkins et al. (2018) demonstrated that approximately 20% of TBI patients exhibit reduced dopamine transporter (DaT) binding, particularly in the caudate nucleus, contributing to cognitive deficits rather than motor impairments. Unlike Parkinson's disease, where dopamine depletion predominantly affects the putamen, TBI-related dopaminergic damage appears more pronounced in the caudate nucleus, explaining why cognitive symptoms often predominate in PCS (Jenkins et al., 2018).

This dopaminergic dysfunction directly impacts multiple cognitive domains, with Chen et al. (2017) reporting that "loss of DA neurons following TBI contributes to cognitive deficits, emotional dysregulation, and increased risk for neuropsychiatric conditions such as depression, anxiety, and substance use disorders." The vulnerability of dopamine-producing neurons in the substantia nigra and ventral tegmental area stems from their long axonal projections and high metabolic activity, making them particularly susceptible to the shearing forces experienced during head trauma (Chen et al., 2017).

Another crucial neurophysiological factor in PCS involves neurovascular coupling (NVC) dysfunction. Fong (2024) describes how brain injuries disrupt the brain's ability to regulate blood flow to active neurons, creating an imbalance where some regions become hypoactive (underperforming) while others become hyperactive (overcompensating). This dysregulation explains why PCS patients often experience seemingly contradictory symptoms—fatigue alongside insomnia, or emotional numbness alongside heightened irritability. Functional NeuroCognitive Imaging (fNCI) can detect these dysfunctions, potentially guiding more targeted rehabilitation approaches (Fong, 2024).

The anatomical basis of specific PCS symptoms has been further clarified by Danielli et al. (2023), who mapped how damage to specific brain regions correlates with distinct symptom clusters. For instance, amygdala dysfunction contributes to emotional instability and anxiety, hippocampal damage leads to memory deficits, and insular cortex involvement results in autonomic symptoms like nausea and dizziness. Disruption to white matter tracts, particularly the superior longitudinal fasciculus and corpus callosum, further impairs communication between brain regions, compromising cognitive integration and processing speed (Danielli et al., 2023).

Non-Pharmacological Intervention Approaches

Research has examined non-pharmacological treatments for persistent post-concussion symptoms (PPCS). Rytter et al. (2021) reviewed approaches like physical exercise, vestibular rehabilitation, psychological interventions, and interdisciplinary rehabilitation. They found potential benefits but noted limited evidence, leading to conditional recommendations. Specific treatments such as vestibular rehabilitation and structured exercise showed modest improvements in symptoms and physical functioning. However, many studies have low methodological quality, stressing the need for rigorous trials with standardized protocols. Personalized treatment plans are vital for effective PCS management (Rytter et al., 2021).

Evidence-Based Strategies for PCS Recovery

Contrary to traditional advice recommending prolonged rest following concussion, current evidence suggests that controlled, progressive activity leads to better outcomes. Fong (2024) reports that "95% of patients undergoing intensive neurorehabilitation experience statistically verified brain function improvement within one week." This approach involves addressing the underlying neurovascular coupling dysfunction through targeted interventions that balance hypoactive and hyperactive brain regions (Fong, 2024).

Physical Activity and Exercise

Moderate, structured physical activity represents a cornerstone of modern PCS management. The Danish National Guidelines reviewed by Yeates et al. (2021) specifically recommend graded exercise programs that gradually increase intensity while remaining below symptom-exacerbation thresholds. This approach not only improves cardiovascular health but also promotes neuroplasticity and reduces inflammation, potentially accelerating recovery. Rytter et al. (2021) found that "vestibular rehabilitation and graded physical exercise programs showed modest effectiveness in reducing vestibular symptoms, improving balance, and enhancing overall physical functioning" in PCS patients.

Cognitive Rehabilitation

Targeted cognitive exercises can improve outcomes for PCS patients more effectively than generic "brain training." Personalized approaches that address specific cognitive domains like attention, processing speed, or executive function are more beneficial. Levin et al. (2019) found combining pharmacological interventions with cognitive therapy results in greater cognitive gains. Techniques using metacognitive strategies, such as self-monitoring and compensatory approaches, are especially effective for functional improvements.

Sleep Optimization

Sleep disturbances are both a symptom and a contributing factor in PCS. Improving sleep hygiene through consistent schedules, suitable evening routines, and environmental changes can enhance recovery outcomes. According to Maher and Flint Rehab (2021), poor sleep "compounds stress effects, impairing reaction time and judgment," which can hinder recovery. Specific interventions may include cognitive-behavioral therapy for insomnia (CBT-I), strategic light exposure to regulate circadian rhythms, and the controlled use of sleep-promoting supplements or medications when necessary.

Technological Support

Emerging technologies offer promising adjuncts to traditional PCS management. Beyond photo-biomodulation (Stevens et al., 2024), other technological approaches include neurofeedback training, virtual reality-based vestibular rehabilitation, and smartphone applications for symptom tracking and cognitive exercises. These tools can increase patient engagement, provide objective measures of progress, and facilitate home-based continuation of therapeutic activities between clinical visits.

Psychosocial Support

The emotional and social aspects of PCS recovery are significant factors that must not be overlooked. Chan et al. (2022) identified several barriers to integrated care for TBI patients, including "lack of education among healthcare providers, limited access to care, and difficulties with technology," and highlighted facilitators such as "engaging patients and families, incorporating compensatory strategies for cognitive challenges, and multidisciplinary collaboration." Their review underscored "the importance of cognitive accommodations in treatment plans" and "the potential benefits of multidisciplinary teams in enhancing patient outcomes and mitigating barriers to care" (Chan et al., 2022).

Establishing effective support systems, addressing psychological comorbidities like anxiety and depression, and fostering realistic expectations about recovery are crucial elements that contribute to improved outcomes. Support groups, available both in-person and online, can provide validation, practical coping strategies, and a sense of community for individuals managing the often-invisible challenges of PCS. The integration of these evidence-based approaches, tailored to individual symptom profiles and preferences, presents the most promising path toward functional recovery from post-concussion syndrome. As research continues to unravel the complex neurobiological foundations of this condition, treatment protocols are expected to become increasingly precise and effective.

Pharmacological Management Strategies

Pharmacological interventions are crucial for managing PCS, especially when non-pharmacological methods fall short. Renga (2021) notes that medications for PCS mainly target symptom relief, addressing headaches, mood issues, and sleep problems. Common treatments include antidepressants, antimigraine medications, and muscle relaxants, though their long-term effectiveness is limited. For neuropsychiatric symptoms, SSRIs are used for depression and anxiety, while anticonvulsants or beta-blockers manage irritability and agitation (Rao et al., 2017). These drugs require careful personalization to avoid adverse effects.

Dopaminergic medications also play a role in treating cognitive deficits post-TBI. Jenkins et al. (2018) found that such injuries often reduce dopamine transporter levels, leading to cognitive issues like slower processing speed and executive dysfunction. Stimulants like methylphenidate have shown promise in improving attention and processing speed but need more extensive trials for optimal dosing and long-term impact (Jenkins et al., 2018). Atypical antipsychotics, such as quetiapine and risperidone, are sometimes used for severe neuropsychiatric symptoms due to their sedative effects. However, they come with significant risks, including metabolic changes and increased cerebrovascular events, necessitating cautious use (Connell et al., 2013).

Emerging Pharmacological Approaches

The understanding of dopaminergic dysfunction in PCS has led to research on targeted treatments. Levin et al. (2019) examined methylphenidate (MPH), a dopamine and noradrenaline reuptake inhibitor, for addressing post-TBI cognitive dysfunction. Their research indicates that "MPH blocks DA and NE reuptake, increasing extracellular neurotransmitter levels and enhancing working memory, attention, and processing speed." Clinical trials have demonstrated that "daily MPH use for 1-2 months leads to sustained improvements in processing speed and working memory," with functional MRI studies showing that MPH "modulates prefrontal and striatal activity, potentially restoring efficient neural processing in TBI patients" (Levin et al., 2019).

The efficacy of MPH follows an inverted U-shaped curve, where optimal dosing must be individualized. Too low a dose proves ineffective, while excessive doses may impair cognitive performance. Neuroimaging biomarkers, such as dopamine transporter availability, may help identify patients most likely to benefit from this therapy. Additionally, combining MPH with cognitive rehabilitation strategies appears to yield more robust improvements than either approach alone (Levin et al., 2019).

Novel Pharmacological Interventions

Photo-biomodulation (PBM) has shown promise as a neuroprotective therapy for mild traumatic brain injury. Stevens et al. (2024) found that red and near-infrared light therapy (660 nm and 810 nm) "modulates mitochondrial function, reduces oxidative stress, and promotes neuroplasticity." The study highlighted that "810 nm PBM yielded the greatest cognitive and motor improvements" due to deeper brain penetration. Histological analysis indicated a reduction in neuroinflammatory response and neuronal cell death.

Botulinum toxin (Botox) therapy is also gaining attention for treating post-concussion headaches and associated depression. Lebow (2021) reviewed clinical trials showing significant improvements in depressive symptoms, especially in women, though it was less effective for those on multiple antidepressants. Botox may reduce negative mood states by inhibiting frowning and blocking neural feedback to the amygdala.

This is relevant for PCS patients with both post-traumatic headaches and depression. Afatato et al. (2021) conducted a meta-analysis indicating Botox significantly improves both conditions, with mean reductions of 8.94 points on the BDI scale for depression and a decrease of 6.27 migraine episodes per month, showing effectiveness across multiple symptom domains.

Emerging Research: Hallucinogens for PCS Treatment

Recent research has been investigating the therapeutic potential of hallucinogens, including psilocybin, ayahuasca, and related psychedelics, for treating post-concussion syndrome (PCS) and mild traumatic brain injuries (mTBIs). These substances appear to have neuroprotective and neuroplastic effects that may facilitate recovery from brain injuries. Pourang (2021) highlighted several compelling case studies, including reports involving former athletes, documenting significant symptom improvements following the administration of psychedelics. These substances seem to promote neurogenesis, reduce neuroinflammation, and enhance brain network complexity, potentially supporting recovery across both cognitive and emotional domains (Pourang, 2021).

Khan et al. (2021) further examined the potential benefits of psychedelics for brain injury recovery, emphasizing their capacity to modulate neuroinflammatory processes and promote structural and functional neuroplasticity. Preclinical studies on psychedelics such as psilocybin and DMT suggest that these compounds may enhance recovery by facilitating new neural connections and improving cognitive flexibility. Despite these promising preliminary findings, additional rigorously designed clinical trials are essential to evaluate the safety profile, therapeutic efficacy, and long-term outcomes associated with psychedelic therapies for individuals with PCS and mTBIs (Khan et al., 2021).

While the integration of psychedelics into mainstream medical practice remains controversial, emerging evidence suggests that these substances may offer novel therapeutic options for PCS patients who have not responded adequately to conventional interventions. The ability of these compounds to target multiple pathophysiological pathways involved in brain recovery presents promising avenues for improved outcomes in PCS management.

Clinical Management Advances and Future Directions

Despite significant progress in understanding PCS, substantial challenges persist in diagnosis and treatment optimization. Renga (2021) emphasized that the predominantly subjective nature of PCS symptoms creates challenges in establishing definitive diagnostic markers, particularly for manifestations like headaches, dizziness, and mood alterations that resist objective quantification. The development of more objective diagnostic tools, including advanced neuroimaging techniques and validated biomarkers, remains a research priority (Renga, 2021).

Looking toward future developments, experts advocate for prospective, longitudinal studies utilizing standardized assessment protocols to advance the field. Polinder et al. (2018) highlighted the importance of interdisciplinary approaches integrating medical, psychological, and social assessments to enhance recovery outcomes and tailor treatments to individual patient needs. Such comprehensive strategies not only address symptomatic manifestations but also target underlying pathophysiological mechanisms of PCS, promoting sustained recovery.

Conclusion

Recent research challenges traditional views on PCS recovery timelines. McInnes et al. (2017) found that around 50% of individuals with a single mTBI had cognitive deficits beyond the acute recovery phase, suggesting a need to reevaluate post-concussion care protocols. Their review identified persistent issues in memory, processing speed, executive function, and attention among those with minor brain injuries. Conventional imaging techniques often fail to detect microstructural changes, potentially leading to underdiagnosis. Advanced imaging like DTI has revealed ongoing microstructural damage such as diffuse axonal injury (McInnes et al., 2017).

These findings impact return-to-work and return-to-play guidelines, which assume cognitive function returns to baseline quickly. For some, deficits may last much longer, affecting occupational performance and quality of life. Extended rehabilitation and cognitive therapy interventions might be necessary for ongoing symptoms (McInnes et al., 2017). The Danish National Clinical Guideline by Yeates et al. (2021) stresses individualized approaches to PCS, including early information, graded exercise, vestibular rehabilitation, manual therapy, psychological treatment, and interdisciplinary rehabilitation.

PCS management is challenging due to heterogeneous symptoms and the interplay of biological, psychological, and social factors. Comprehensive treatment approaches tailored to individual patient needs are crucial. Personalized intervention strategies, integrating pharmacological and non-pharmacological modalities, are essential. Shared decision-making and family support play significant roles in managing symptoms.

Future research should aim at standardizing diagnostic criteria, improving clinical trial methodologies, and developing individualized treatment protocols. Novel therapeutic approaches, such as neurostimulation and virtual reality for cognitive rehabilitation, show promise. Better understanding PCS pathophysiology will help healthcare providers deliver targeted support, enhancing quality of life and functional outcomes for affected individuals.

References

1. Afatato, O., Moulin, T. C., Pisanu, C., Babasieva, V. S., Russo, M., Aydinlar, E. I., Torelli, P., Chubarev, V. N., Tarasov, V. V., Schiöth, H. B., & Mwinyi, J. (2021). High efficacy of onabotulinumtoxinA treatment in patients with comorbid migraine and depression: a meta-analysis. Journal of Translational Medicine, 19(1), 133. https://doi.org/10.1186/s12967-021-02801-w

2. Chan, V., Toccalino, D., Omar, S., Shah, R., & Colantonio, A. (2022). A systematic review on integrated care for traumatic brain injury, mental health, and substance use. PLoS ONE, 17(3), e0264116. https://doi.org/10.1371/journal.pone.0264116

3. Chen, Y.-H., Huang, E. Y.-K., Kuo, T.-T., Miller, J., Chiang, Y.-H., & Hoffer, B. J. (2017). Impact of traumatic brain injury on dopaminergic transmission. Cell Transplantation, 26(7), 1156-1168. https://doi.org/10.1177/0963689717714105

4. Chiu, S.-L., Osternig, L., & Chou, L.-S. (2013). Concussion induces gait inter-joint coordination variability under conditions of divided attention and obstacle crossing. Gait & Posture, 38(4), 717-722. https://doi.org/10.1016/j.gaitpost.2013.03.010

5. Cleveland Clinic. (2024, October 30). Persistent post-concussive symptoms (Post-concussion syndrome). Cleveland Clinic. [URL]

6. Connell, R., Zeier, K., & Thomas, C. J. (2013). A review of atypical antipsychotics and their utility in post-traumatic stress disorder. Mental Health Clinician, 2(7), 187-194. https://doi.org/10.9740/mhc.2013.07.187

7. Danielli, E., Simard, N., DeMatteo, C. A., Kumbhare, D., Ulmer, S., & Noseworthy, M. D. (2023). A review of brain regions and associated post-concussion symptoms. Frontiers in Neurology, 14, 1136367. https://doi.org/10.3389/fneur.2023.1136367

8. Emamzadeh, A. (2021, May 5). How Botox injections may reduce depression. Psychology Today. https://www.psychologytoday.com/us/blog/finding-new-home/202105/how-botox-injections-may-reduce-depression

9. Fernandes, C., Dapkute, A., Watson, E., Kazaishvili, I., Chądzyński, P., Varanda, S., Di Antonio, S., Munday, V., MaassenVanDenBrink, A., & Lamp, C. (2024). Migraine and cognitive dysfunction: A narrative review. The Journal of Headache and Pain, 25(221). https://doi.org/10.1186/s10194-024-01923-y

10. Fong, A. (2024). Concussion, TBI, and hypoxic brain injury recovery: Patient guide. Cognitive FX. https://www.cognitivefxusa.com/blog/brain-injury-recovery

11. Jenkins, P. O., De Simoni, S., Bourke, N. J., Fleminger, J., Scott, G., Towey, D. J., Svensson, W., Khan, S., Patel, M., Greenwood, R., Cole, J. H., & Sharp, D. J. (2018). Dopaminergic abnormalities following traumatic brain injury. Brain, 141(3), 797-810. https://doi.org/10.1093/brain/awx357

12. Khan, S. M., Carter, G. T., Aggarwal, S. K., & Holland, J. (2021). Psychedelics for brain injury: A mini review. Frontiers in Neurology, 12, 685085. https://doi.org/10.3389/fneur.2021.685085

13. Lacerte, M., Shapshak, A. H., & Mesfin, F. B. (2023). Hypoxic brain injury. In StatPearls. StatPearls Publishing.

14. Lebow, H. I. (2021, August 30). Botox for depression. Psych Central. https://www.psychcentral.com/depression/botox-for-depression

15. Levin, H., Troyanskaya, M., Petrie, J., Wilde, E. A., Hunter, J. V., Abildskov, T. J., & Scheibel, R. S. (2019). Methylphenidate treatment of cognitive dysfunction in adults after mild to moderate traumatic brain injury: Rationale, efficacy, and neural mechanisms. Frontiers in Neurology, 10, 925. https://doi.org/10.3389/fneur.2019.00925

16. Llamas, C. (2024, November 26). The complete guide to Botox for migraine: What you need to know. Migraine Again. https://www.migraineagain.com/botox-for-migraine/

17. Maher, C., & Flint Rehab. (2021). Overstimulation after brain injury: Managing sensory overload. Flint Rehab. https://www.flintrehab.com/brain-injury-sensory-overload

18. Mayo Clinic. (2024, October 30). Persistent post-concussive symptoms (Post-concussion syndrome). Mayo Clinic. [URL]

19. McInnes, K., Friesen, C. L., MacKenzie, D. E., Westwood, D. A., & Boe, S. G. (2017). Mild traumatic brain injury (mTBI) and chronic cognitive impairment: A scoping review. PLOS ONE, 12(4), e0174847. https://doi.org/10.1371/journal.pone.0174847

20. Meylakh, N., & Henderson, L. A. (2022). Exploring alterations in sensory pathways in migraine. The Journal of Headache and Pain, 23(5). https://doi.org/10.1186/s10194-021-01371-y

21. NHS Inform. (2025, January 15). Post-concussion syndrome. NHS Inform. https://www.nhsinform.scot/illnesses-and-conditions/injuries/head-and-neck-injuries/concussion/post-concussion-syndrome

22. Polinder, S., Cnossen, M. C., Real, R. G. L., Covic, A., Gorbunova, A., Voormolen, D. C., Master, C. L., Haagsma, J. A., Diaz-Arrastia, R., & von Steinbuechel, N. (2018). A multidimensional approach to post-concussion symptoms in mild traumatic brain injury. Frontiers in Neurology, 9, 1113. https://doi.org/10.3389/fneur.2018.01113

23. Pourang, D. (2021, July 15). Healing traumatic brain injuries with psychedelics. MUD/WTR. https://mudwtr.com/blogs/trends-with-benefits/healing-traumatic-brain-injuries-with-psychedelics

24. Rao, V., Syeda, A., Roy, D., Peters, M. E., & Vaishnavi, S. (2017). Neuropsychiatric aspects of concussion: Acute and chronic sequelae. Concussion, 2(1), CNC29. https://doi.org/10.2217/cnc-2016-0018

25. Renga, V. (2021). Clinical evaluation and treatment of patients with postconcussion syndrome. Neurology Research International, 2021, 1-12. https://doi.org/10.1155/2021/5567695

26. Romm, J. (2015, October 26). Elevated CO2 levels directly affect human cognition, new Harvard study shows. ThinkProgress. Retrieved from https://archive.thinkprogress.org

27. Rytter, H. M., Graff, H. J., Henriksen, H. K., Aaen, N., Hartvigsen, J., Hoegh, M., Næss-Schmidt, E. T., Pedersen, L. L., Schytz, H. W., Thastum, M. M., Zerlang, B., & Callesen, H. E. (2021). Nonpharmacological treatment of persistent postconcussion symptoms in adults: A systematic review and meta-analysis and guideline recommendation. JAMA Network Open, 4(11), e2132221. https://doi.org/10.1001/jamanetworkopen.2021.32221

28. Stevens, A. R., Hadis, M., Thareja, A., Anderson, F. G., Milward, M. R., Di Pietro, V., Belli, A., Palin, W., Davies, D. J., & Ahmed, Z. (2024). Photobiomodulation improves functional recovery after mild traumatic brain injury. Bioengineering & Translational Medicine, 10(2), e10727. https://doi.org/10.1002/btm2.10727

29. Webster, B. J. (2011). Lost & found: A survivor's guide for reconstructing life after a brain injury. Lash & Associates Publishing/Training Inc.

30. Yeates, K. O., Schneider, K. J., & Silverberg, N. D. (2021). Advances in clinical management of persistent postconcussion symptoms—The Danish national clinical guideline. JAMA Network Open, 4(11), e2132424. https://doi.org/10.1001/jamanetworkopen.2021.32424

31. Zebenholzer, K., Rudel, E., Frantal, S., Brannath, W., Schmidt, K., Wöber-Bingöl, Ç., & Wöber, C. (2011). Migraine and weather: A prospective diary-based analysis. Cephalalgia, 31(4), 391-400. https://doi.org/10.1177/0333102410385580