**2. Epidemiology**

The global incidence of TBI is estimated at 939 cases per 100,000 people – which translates to 69 million people sustain a TBI every year [8]. Decreasing incident (4.4%) and increasing prevalence (6.6%) of TBI in the United States during 1990 through 2017 are reported by the Global Burden of Disease Study, with the latest

prevalence and incidence reported are 2.104 and 0.961 million, respectively. TBI incidence is among the highest compared to other neurological disorders, even with age-adjustment at 285 cases per 100,000 people [9]. Pediatric TBI contributes to a global incident range of 47–280 per 100,000 children [10]. Changes in Coronavirus disease 19 (COVID-19) pandemic circumstances since 2020 seem to affect TBI epidemiology as implied by the significant decrease in mild TBI incident for children aged 0–5 years (44%) and 6–17 years (93%) in Canada [11].

The epidemiological characteristics are also invariably affected by geographical and sociodemographic features. Countries with the lowest and highest incidence are Sweden (12 cases per 100,000) and Australia (486 cases per 100,000). Higher incidence, severity, and mortality in pediatric TBI are observed in rural as opposed to urban areas [12]. Bimodal age distribution with peaks at 0–4 years and 14–18 years with male-gender preponderance in the pediatric population is observed [13]. Meanwhile, the role of race and socioeconomic status requires further confirmation [10].

The most common injury mechanisms are falls and motor vehicle accidents, although the relative proportions vary by age distribution. The majority of pediatric TBI cases are mild (70–90%), and severe TBI only accounts for 3–7% of all cases. Consistently, the hospitalization rate is 129 per 100,000 in pediatric population and over 90% recover [10, 13, 14]. Nevertheless, 88% of concussions are left undiagnosed and one-third of properly diagnosed cases may experience ongoing sequelae, which would remain undetected until the development reached frontal lobe maturity [1, 14].
