ABSTRACT
The authors analysed retrospectively, 69 cases of chronic subdural hematoma admitted to the Department of Neurological Surgery, from January 1992 to February 1995. All hematomas were operated on by one burr hole trephination and continuous closed-system cather drainage system. The results were as follows: 1) Male was more frequently involved than female with ratio of 5.3:1 and the incidence was prredominent in the patients whose ages were over 50. 2) History of head trauma was found in 52 cases(75.4%), among which habitual alcoholism was found in 6 cases(8.7%). 3) The major symptoms and signs at admission were headache(55.1%), hemiparesis(44.9%), and mental changes(30.4%). 4) On the brain CT scan, hematoma showed low, iso, mixed, and high in density, and the shapes of hematoma were crescenteric, biconvex, planoconvex, and concave in order of frequency. 5) We have found a significant relationship between the neurological grade at admission and the prognosis, and noted full recovery in 45 cases(65.2%) and no d eath as a result of 1-burr hole trephination.