Beyond the Primary Blow
by Stephanie Ogura, ND
Concussions, also referred to as mild traumatic brain injuries (TBIs), account for approximately 80% to 95% of all TBIs. In 2022, just over 573,000 Canadians aged 12 and older (about 2%) reported suffering a concussion in the past year.[i] A direct traumatic blow to the head is a significant cause, but indirect traumatic forces elsewhere in the body can also lead to an acute acceleration/deceleration injury to the brain, which can also lead to a concussion.[ii] Understanding risk factors and the complex interplay between the primary and secondary effects of concussions is essential for developing effective strategies to mitigate long term-consequences.
Symptoms of a concussion are wide-ranging and could include symptoms falling into four main categories:
- Physical/somatic: headache, dizziness, difficulty with balance, visual changes. Loss of consciousness is observed in less than 10% of cases.
- Affective/emotional: irritability, change in mood.
- Cognitive: confusion/disorientation, amnesia, mental fogginess, difficulty concentrating.
- Sleep: drowsiness, sleeping less/more than usual, difficulty falling asleep.
The duration of symptoms may be variable. According to the 2019 survey above, overall median time of resolution of symptoms is 30 days. Mean recovery time varied according to sex. Males reported a mean recovery time of 14 days while female responders reported a mean recovery time of 60 days.i
Persistent post-concussion symptoms (PPCS), defined as symptoms lasting over three months, have been associated with a reduction in health-related quality of life. PPCS can affect 11% to 25% of those injured. Common symptoms seen in patients with post-concussive syndrome include headache, fatigue, vision changes, disturbances in balance, confusion, dizziness, insomnia, neuropsychiatric symptoms, and difficulty concentrating.[iii] PPCS has lasting effects on cognition, memory, learning and executive function.
Risk factors associated with persistent symptoms following a concussion include history of past concussion, being female, older age, having somatic complaints (e.g., headache, neck or back pain) after the injury, and generalized anxiety .[iv]
Primary injury is characterized by the displacement and mechanical damage to brain tissue which results in the stretching of neurons, glial cells, and blood vessels and altering blood-brain barrier (BBB) permeability and disruption in metabolism.
The secondary injury involves complex processes that are initiated within minutes of the primary injury, and could persists for days, months or years. Secondary injury processes include:
- Flux of intracellular ions (influx of calcium, efflux of potassium).
- Release of excitotoxic neurotransmitters (e.g., glutamate).
- Increased sodium-potassium ion pump activity results in excessive ATP consumption and glucose metabolism.
- Reduced blood flow.
- Cytoplasmic and nuclear proteins released from injured cells act as damage-associated molecular patterns (DAMPs), which are potent stimulators of central and systemic immune responses.
- BBB disruption allows for the infiltration of peripheral immune cells, including leukocytes, into brain parenchyma. Infiltrating immune cells secrete chemokines and cytokines that mobilize and activate resident glial cells such as microglia and astrocytes, and exacerbate the infiltration of peripheral immune cells.
- Chronic activation of microglia results in the persistent production and release of proinflammatory molecules including reactive oxygen species (ROS) .
- Activation of the hypothalamic-pituitary-adrenal (HPA) axis and the sympathetic branch of the autonomic nervous system, resulting in the release of glucocorticoids and catecholamines.
- Dysfunction in neural and systemic pathways of the brain-gut axis.
Naturopathic Approach*
*Disclaimer: the supportive naturopathic approach is meant for health-care providers only. To learn more about naturopathic approaches, please contact your local Naturopathic Doctor or Integrative Health Care Provider.
A whole-person approach to the primary and secondary effects of a concussion will depend on several factors including age, sex, nature of the injury and concussions, based on the available research, include curcumin, resveratrol, omega 3 fatty acids and melatonin.[vii] Ingredients [MK1] that address underlying mechanisms include:
Lion’s mane (Hericium erinaceus): in vivo mild traumatic brain injury animal study demonstrated H. erinaceus administered following brain injury facilitated recovery, prevented neuronal injury and inactivation of microglia through the Nrf2-mediated antioxidant pathway.[viii]
Alpha lipoic acid: in vivo animal study demonstrated ALA treatment alleviated TBI-induced neuron cell apoptosis and improved neurobehavioural function by up-regulation of Nrf2 expression and its downstream protein factors after TBI.[ix]
Citicoline: meta-analysis indicated beneficial effects of citicoline administered in the acute phase of head-injured patients (started within the first 24 h) increasing independence at the end of the scheduled clinical trial follow-up.[x] A double blind placebo-controlled study of patients with postconcussion symptoms one month after mild to moderate close head injury (n=14) showed that citicoline produced a significantly greater reduction of symptoms than placebo.[xi]
L-Theanine: neuroprotective effect in the vivo animal model of stroke.[xii] In vivo animal study demonstrated that L-theanine attenuated the destruction of intestinal villi and crypt depth, restored gut microbiota homeostasis and immune balance following heat stress.[xiii]
[i] https://www.statcan.gc.ca/o1/en/plus/5563-concussions-happen-home-too
[ii] Ferry B, DeCastro A. Concussion. [Updated 2023 Jan 9]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2024 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK537017/
[iii] Permenter CM, Fernández-de Thomas RJ, Sherman AL. Postconcussive Syndrome. [Updated 2023 Aug 28]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2024 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK534786/
[iv] Déry, Julien et al. “Prognostic factors for persistent symptoms in adults with mild traumatic brain injury: an overview of systematic reviews.” Systematic reviews vol. 12,1 127. 20 Jul. 2023, doi:10.1186/s13643-023-02284-4
[v] : Mavroudis, Ioannis, et al. ‘The Neuropathology of Concussion’. Concussion – State-of-the-Art, IntechOpen, 2 Nov. 2023. Crossref, doi:10.5772/intechopen.112459.
[vi] Hanscom, Marie et al. “Brain-gut axis dysfunction in the pathogenesis of traumatic brain injury.” The Journal of clinical investigation vol. 131,12 (2021): e143777. doi:10.1172/JCI143777
[vii] Ashbaugh, Andrew DO, MPH; McGrew, Christopher MD, FACSM. The Role of Nutritional Supplements in Sports Concussion Treatment. Current Sports Medicine Reports 15(1):p 16-19, January/February 2016. | DOI: 10.1249/JSR.0000000000000219
[viii] Lee, Kam-Fai et al. “The Cerebral Protective Effect of Novel Erinacines from Hericium erinaceus Mycelium on In Vivo Mild Traumatic Brain Injury Animal Model and Primary Mixed Glial Cells via Nrf2-Dependent Pathways.” Antioxidants (Basel, Switzerland) vol. 13,3 371. 19 Mar. 2024, doi:10.3390/antiox13030371
[ix] Wei, Wuting et al. “Alpha lipoic acid inhibits neural apoptosis via a mitochondrial pathway in rats following traumatic brain injury.” Neurochemistry international vol. 87 (2015): 85-91. doi:10.1016/j.neuint.2015.06.003
[x] Citicoline for the Management of Patients with Traumatic Brain Injury in the Acute Phase: A Systematic Review and Meta-Analysis.” Life (Basel, Switzerland) vol. 13,2 369. 29 Jan. 2023, doi:10.3390/life13020369
[xi] Xia, Dayong et al. “Alpha lipoic acid inhibits oxidative stress-induced apoptosis by modulating of Nrf2 signalling pathway after traumatic brain injury.” Journal of cellular and molecular medicine vol. 23,6 (2019): 4088-4096. doi:10.1111/jcmm.14296
[xii] Zukhurova, Mavdzhuda et al. “L-theanine administration results in neuroprotection and prevents glutamate receptor agonist-mediated injury in the rat model of cerebral ischemia-reperfusion.” Phytotherapy research : PTR vol. 27,9 (2013): 1282-7. doi:10.1002/ptr.4868
[xiii] Liu, Sha et al. “L-Theanine alleviates heat stress through modulation of gut microbiota and immunity.” Journal of the science of food and agriculture vol. 104,4 (2024): 2059-2072. doi:10.1002/jsfa.13095