Spontaneous regression and progression in non-evacuated acute subdural hematoma: A prospective analysis of predictive factors

Objective: To determine the frequency of progression in conservatively managed patients with acute subdural hematoma (ASDH) requiring surgical intervention and identify factors associated with progression or spontaneous regression. Methodology: This prospective observational cohort study was conducted at the Department of Neurosurgery, Unit-I, Punjab Institute of Neurosciences, Lahore, Pakistan. Patients admitted with conservatively managed ASDH between June 2026 and September 2026 underwent close neurological monitoring and serial CT imaging at intervals of 48 hours post-admission, or earlier if neurological deterioration was observed; radiological variables were collected. Statistical analysis was performed using SPSS Version 26. After descriptive statistics, we used the Mann-Whitney U test and the chi-square test or Fisher’s exact test to identify factors associated with hematoma progression or spontaneous regression requiring surgical intervention. Results: The mean age of the 132 patients in this cohort was 45.30±16.46 years, with a male predominance of 74.2% (98). Patients with spontaneous regression of ASDH had a significantly higher proportion of females and mixed density on CT (80.9% vs 62.5% and 20.8% vs 3.5%, respectively; p<0.05). Similarly, on comparing with spontaneous regression of ASDH, patients with progression of ASDH had significantly low GCS at presentation, higher hematoma volume and thickness and greater midline shift developed higher rates of progression when compared with spontaneous resolution i.e., U = 1638.5.0, p = 0.066, U = 1108.0, p 0.001, U = 1389.0, p = 0.003 and U = 1244.0, p<0.001 respectively. Conclusion: Male gender and low GCS at presentation are clinical factors associated with progression of ASDH after TBI. In contrast, among radiological factors, higher hematoma volume and thickness and greater midline shift on CT scan at presentation were associated with progression of ASDH necessitating surgical evacuation. Conversely, occurrence of mixed density lesion on presenting CT scan is associated with spontaneous regression of ASDH after trauma.