Diffuse Sulcal Hyperintensity on MRI as a Radiological Correlate of Transient Neurological Deficits in Chronic Subdural Hematoma

Background Transient neurological deficits (TND) may present as the initial symptom of chronic subdural hematoma (CSDH). Although a relationship between sulcal hyperintensity (SHI) on FLAIR images and TND has been suggested, existing evidence is limited to case reports and small-scale cohort studies. This study aimed to investigate the association between diffuse SHI and TND in patients with CSDH. Methods This single-center retrospective study included 127 patients with CSDH who underwent perioperative CT and MRI including FLAIR sequences, between January 2017 and March 2025. To identify factors associated with TND, univariate and multivariable logistic regression analyses were used to estimate odds ratios (ORs) with 95% confidence intervals (CIs). SHI on FLAIR was defined as marked hyperintensity along cerebral sulci adjacent to the hematoma, categorized as diffuse or focal. Results Among the 127 patients (median age, 82 [74–86] years, 86 male) with CSDH, 22 (median age, 81 [72–85] years, 17 male) presented with diffuse SHI. Of the 22 patients with diffuse SHI, nine (40.91%) underwent TND. The presence of diffuse SHI was independently associated with TND (adjusted OR; 17.07, 95% CI; 4.71–73.23, p < 0.01). Conclusions This study demonstrates a significant correlation between preoperative TND and diffuse SHI in patients with CSDH. These findings may serve as indicators of TND in patients with CSDH, providing useful information that can complement existing diagnostic methods.