Chronic motor performance following different traumatic brain injury severity—A systematic review

Abstract

IntroductionTraumatic brain injury (TBI) is now known to be a chronic disease, causing ongoing neurodegeneration and linked to increased risk of neurodegenerative motor diseases, such as Parkinson's disease and amyotrophic lateral sclerosis. While the presentation of motor deficits acutely following traumatic brain injury is well-documented, however, less is known about how these evolve in the long-term post-injury, or how the initial severity of injury affects these outcomes. The purpose of this review, therefore, was to examine objective assessment of chronic motor impairment across the spectrum of TBI in both preclinical and clinical models.MethodsPubMed, Embase, Scopus, and PsycINFO databases were searched with a search strategy containing key search terms for TBI and motor function. Original research articles reporting chronic motor outcomes with a clearly defined TBI severity (mild, repeated mild, moderate, moderate–severe, and severe) in an adult population were included.ResultsA total of 97 studies met the inclusion criteria, incorporating 62 preclinical and 35 clinical studies. Motor domains examined included neuroscore, gait, fine-motor, balance, and locomotion for preclinical studies and neuroscore, fine-motor, posture, and gait for clinical studies. There was little consensus among the articles presented, with extensive differences both in assessment methodology of the tests and parameters reported. In general, an effect of severity was seen, with more severe injury leading to persistent motor deficits, although subtle fine motor deficits were also seen clinically following repeated injury. Only six clinical studies investigated motor outcomes beyond 10 years post-injury and two preclinical studies to 18–24 months post-injury, and, as such, the interaction between a previous TBI and aging on motor performance is yet to be comprehensively examined.ConclusionFurther research is required to establish standardized motor assessment procedures to fully characterize chronic motor impairment across the spectrum of TBI with comprehensive outcomes and consistent protocols. Longitudinal studies investigating the same cohort over time are also a key for understanding the interaction between TBI and aging. This is particularly critical, given the risk of neurodegenerative motor disease development following TBI.

Reactive gliosis in traumatic brain injury: a comprehensive review

“…Traumatic brain injury-induced neuropathology significantly influences both motor and cognitive dysfunction ( Gorgoraptis et al, 2019 ; Corrigan et al, 2023 ). Behavioral outcomes in various animal models that have been established to replicate diverse clinical TBI pathologies, can consequently vary.…”

A pre-existing Toxoplasma gondii infection exacerbates the pathophysiological response and extent of brain damage after traumatic brain injury in mice

“…Traumatic brain injury (TBI) is a global health concern, and the estimated annual incidence exceeds 27 million worldwide [ 1 , 2 ]. TBI survivors often experience debilitating motor, cognitive, social, and emotional deficits that can persist chronically [ 3 – 6 ]. These long-term functional consequences are believed to be underpinned by neuropathology resulting from both primary (i.e., brain damage caused by mechanical forces at the time of impact) and secondary injury mechanisms (i.e., delayed and/or evolving processes triggered by the primary insult), including influential secondary pathways such as neuroinflammation, excitotoxicity, and oxidative stress [ 7 – 10 ].…”

Long Noncoding RNA VLDLR-AS1 Levels in Serum Correlate with Combat-Related Chronic Mild Traumatic Brain Injury and Depression Symptoms in US Veterans

“…The chronic effects of rmTBI may also include lower cognitive ability, depression or a decrease in the quality of life [10]. Fewer than 10% of patients with mTBI seek care for these symptoms in the following years [11,12].…”