Factors Associated With Subdural Hygroma Following Mild Traumatic Brain Injury.

Objective: Subdural hygroma (SDG) is a complication of traumatic brain injury (TBI). In particular, the outcome and outpatient treatment period may vary depending on the occurrence of SDG. However, the pathogenesis of SDG has not been fully elucidated. Therefore, this study aimed to identify the risk factors associated with the occurrence of SDG after mild TBI. Methods: We retrospectively analyzed 250 patients with mild TBI admitted to a single institution between January 2021 and December 2021. The SDG occurrence and control groups were analyzed according to the risk factors of SDG, such as age, history, initial computed tomography (CT) findings, and initial laboratory findings. Results: The overall occurrence rate of SDG was 31.6% (n=79). A statistically significant association was found between preoperative diagnoses and the occurrence of SDG, such as subarachnoid hemorrhage (odds ratio [OR], 2.36; 95% confidence interval [CI], 1.26-4.39) and basal skull fracture (OR, 0.32; 95% CI, 0.12-0.83). Additionally, age ≥70 years (OR, 3.20; 95% CI, 1.74-5.87) and the use of tranexamic acid (OR, 2.12; 95% CI, 1.05-4.54) were statistically significant factors. The prognostic evaluation of patients using the Glasgow Outcome Scale (GOS) did not show any statistical differences between patients with and without SDG. Conclusion: SDG was not associated with the prognosis of patients assessed using the GOS. However, depending on the occurrence of SDG, differences in patient symptoms may occur after mild TBI. Therefore, the early evaluation of patients with mild TBI and determination of the probability of developing SDG are important.