Risk factors of bilateral chronic subdural hematoma compared to unilateral chronic subdural hematoma

ABSTRACT

Chronic subdural hematoma (CSDH) is a common and relatively benign disease. The aim of this study was to investigate the differences between unilateral and bilateral chronic subdural hematoma in terms of predisposing factors. A retrospective analysis was made of all patients who underwent operation for CSDH at our institution between January 2010 and December 2015. Patients were divided into two groups (unilateral versus bilateral CSDH) and univariate and multivariate analysis was performed to assess demographic data, symptoms, cause of SDH, medical history, laboratory data, and initial radiologic findings. A total of 246 patients were enrolled. There were 63 (25.6%) patients with bilateral CSDH. There were no significant differences concerning sex and initial symptoms between the two groups. Only malignancy history was a significant risk factor for bilateral CSDH in both univariate and multivariate analysis (p = 0.002 and 0.001, respectively). In multivariate analysis, diabetes mellitus (OR 2.03, 95% CI 1.05 - 3.92, p = 0.0350), malignancy (OR 5.09, 95% CI 1.93 - 13.40, p= 0.0010), membrane septation (OR 0.50, 95% CI 0.25 - 0.96, p = 0.0392), and brain atrophy (mild OR 2.34, 95% CI 1.16 - 4.71, p = 0.0164, moderate OR 3.85, 95% CI 1.32-11.18, p = 0.0131) were significantly associated with bilateral CSDH. The present study suggests that diabetes mellitus, malignancy, membrane septation and mild to moderate brain atrophy is independent predisposing factors of bilateral CSDH.