Background/Objectives: Traumatic brain injury (TBI) is a complex condition and a leading cause of injury-related disability and death, with significant impacts on patient outcomes. Extracranial organ involvement plays a critical role in the outcome of patients following TBI. Method: This review aims to provide a comprehensive overview of the pathophysiology, clinical presentation, and challenges in diagnosing patients with autonomic dysfunction after TBI. The databases used in this review include PubMed/MEDLINE, Cochrane Central Register, and Scopus. Results: Of 172 articles identified for screening, 98 were ultimately included in the review. Conclusion: This review summarized the current evidence on the pathophysiology, clinical presentation, and diagnosis of early autonomic dysfunction. It also emphasizes the effects of autonomic dysfunction on end-organ damage. These insights aim to guide clinicians and researchers toward improving the care for and understanding of autonomic dysfunction in TBI patients, while underscoring the need for further research in this area.

Background: Beta-blockers have been studied for potential benefits in traumatic brain injury (TBI). This study aimed to investigate the association between early beta-blocker exposure and brain injury biomarkers following moderate-severe TBI. Methods: We conducted a retrospective cohort study using data from the Transforming Clinical Research and Knowledge in TBI (TRACK-TBI) study. Patients ⩾ 17 years with moderate-severe TBI (Glasgow Coma Scale 3–12) admitted to an intensive care unit (ICU) were included. Early beta-blocker exposure was defined as administration within the first 72 h of admission. The primary outcome was blood-based brain injury biomarker levels on day 3 post-injury. Biomarkers included glial fibrillary acidic protein (GFAP), ubiquitin C-terminal hydrolase-L1 (UCH-L1), neuron-specific enolase (NSE), S100 calcium-binding protein B (S100B), and the inflammatory biomarker C-reactive protein (CRP). Propensity-weighted models analyzed the association between beta-blocker exposure and biomarker levels. Results: Among 450 patients, 31 (7%) received beta-blockers (BB+). The mean (SD) age of BB+ patients was 51.4 (16.2) years, compared to 39.5 (17.0) years for unexposed patients (BB−). BB+ group was associated with a decreased NSE level on day 3 (ratio = 0.71, 95% CI 0.52–0.96, p = 0.026), although this was not significant after adjusting for multiple comparisons ( p = 0.13). For secondary outcomes, UCH-L1 levels increased on day 5 in the BB+ group (ratio = 1.62, 95% CI 1.12- 2.36, p = 0.011), but this was not significant after adjustment ( p = 0.55). The NSE level on day 14 decreased in the BB+ group (ratio 0.45, 95% CI 0.30–0.66, p < 0.001) and remained significant after adjustment ( p = 0.005). Conclusions: There was no association between early beta-blocker exposure and the primary outcome which was blood-based brain injury biomarker levels on day 3. In exploratory analysis, we found that early beta-blocker may associated with decreased NSE level on day 14. Due to the retrospective nature of the study and the use of propensity-weighted analysis to identify associations, direct clinical practice changes cannot be recommended. However, the significant association with NSE level warrants further investigation through prospective studies or randomized controlled trials to confirm the potential neuroprotective effect of early beta-blocker exposure on neuronal cellular injury.