Subconcussive Impacts in Contact Sports: Neuroinflammatory Mechanisms and Neuropsychiatric Consequences – A Narrative Review
DOI:
https://doi.org/10.12775/QS.2026.72.74926Keywords
Subconcussive head impacts, neuroinflammation, Neurofilament Light Chain, executive function;, contact sports, traumatic brain injury (TBI)Abstract
Background. Subconcussive head impacts (SHIs) in contact sports induce subclinical axonal injury, microglial activation, and neuroinflammation without acute concussive symptoms, potentially disrupting frontolimbic networks.
Aim. To synthesize evidence on pathophysiological cascades linking cumulative SHIs to fluid neuro-biomarkers (NfL, GFAP, cytokines) and downstream executive and affective dysfunction.
Material and methods. A targeted review of literature (2015–2026) across PubMed, Scopus, and Web of Science evaluating SHI biomechanics, biomarkers, and neuropsychiatric outcomes in athletes was conducted.
Results. Repetitive SHIs trigger subclinical axonal shearing and microglial M1 polarization, elevating serum NfL, GFAP, and proinflammatory cytokines (IL-6, TNF-α). Neuroinflammation in frontostriatal and frontolimbic circuits (DLPFC, amygdala) directly correlates with executive dysfunction, behavioral impulsivity, and affective dysregulation.
Conclusions. Cumulative SHIs cause progressive neuroinflammatory damage. Longitudinal tracking combining fluid biomarkers with digital neurocognitive screening is essential for early risk stratification in contact sports.
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