Abstract：Objective To evaluate the relationship between occipital cranial morphology and location of chronic subdural hematoma (CSDH). Methods The computed tomographic scans (CT) or magnetic resonance images(MRI) of 98 consecutive patients who underwent surgery for CSDH in the Air Force General Hospital of PLA between January 2002 and April 2012 were re-evaluated, and the symmetry of the occipital cranial vault, and the location of the CSDH were all checked. Results The mean age of the patients was 71.00?13.96 years (age range, 37-93 years).The occipital cranial vault was symmetrical in 37 patients (37.8%) and asymmetrical in 61 patients (62.2%).The asymmetric crania were flat on the right side in 41 patients, on the left side in 20 patients. CSDH was bilateral in 20 patients (20.4%) and unilateral in 78 patients (79.6%), and the unilateral hematomas were located on the right side in 30 patients and on the left side in 48 patients. It was more commonly bilateral in patients with a symmetrical occipital skull vault than those with an asymmetrical one and this difference was statistically significant (P=0.021). In 61 patients with an asymmetric occipital cranial vault, the CSDH was bilateral in 8 patients. In the remaining 53 patients, the CSDH located on the opposite side of the flat side in 37 patients, and located on the same side of the flat side in 16 patients. Conclusions Bilateral CSDH is common in patients with symmetrical occipital cranial vault. In asymmetrical occipital cranial vault, CSDH is usually located on the opposite to the flat side of the skull.
2012, Vol. 23 
