Clinical Characteristics of Bilateral versus Unilateral Chronic Subdural Hematoma

OBJECTIVE: Chronic subdural hematoma (CSDH) is a common intracranial hemorrhage that is associated with significant morbidity. Bilateral lesions are occasionally found in neurosurgical practice. The purpose of this study is to analyze clinical characteristics of bilateral CSDH compared with unilateral CSDH. METHODS: Between January 2005 and January 2013, the authors treated 114 surgical patients with CSDH. Clinical presentations, precipitating factors, computed tomography (CT) findings, postoperative complications, and outcomes of patients were retrospectively analyzed in the bilateral and unilateral CSDH groups. RESULTS: Bilateral CSDH was identified in 28 (24.6%) of the 114 CSDH patients. The mean age was 77.85 years in the bilateral CSDH group. The frequency of altered consciousness as a presenting symptom was significantly higher in the bilateral CSDH, and that of hemiparesis was significantly higher in the unilateral CSDH (p=0.015). Diabetes mellitus was more common in the bilateral CSDH (p=0.001). CT scans revealed significant differences in the degree of midline shift (p=0.001). The mean modified Rankin scale at discharge was 1.5 in the bilateral CSDH group and 0.6 in the unilateral group (p=0.019). CONCLUSION: Bilateral CSDH showed different clinical characteristics from unilateral CSDH. Bilateral CSDH is prone to occurrence in the patient of old and diabetics. The patients of bilateral CSDH seem to reveal worse mental status and neurologic sign than unilateral CSDH in both baseline and postoperative state.