[Factors responsible for prognosis of chronic subdural hematomas]

239 adult patients with chronic subdural hematoma were reviewed in order to analyse recent characteristics, and the responsible factors affecting functional prognosis. Patients with hygroma, diagnosed by the nature of the subdural fluid, were included since the mode of treatment is regarded as the same. 226 cases were surgically treated with standardized two burr-holes and irrigation, within which 24 cases required reoperation and 13 cases were medically treated since the hematoma was small and there was no mass effect. Functional outcome was evaluated by the Glasgow Outcome Scale. The number of cases have gradually increased, especially among elderly patients and in female ones. 179 patients were categorised as having good recovery, 25 as moderately disabled, 27 as severely disabled, 3 as persistently vegetative, and 5 patients died. Aged patients with preoperative mental change and a disturbance of consciousness, with low dense or mixed dense hematoma without sizable mass effect, with watery-clear or xanthochromic fluid cavity tended to have poorer outcome. Also the prognosis of patients not operated on was poor despite the spontaneous disappearance of the cavity. The delay in re-expansion of the brain had less bearing on the functional prognosis than might be expected. The factors which impeded good recovery were primary brain damage due to preceding diseases such as cerebral infarct or hemorrhage, initial head injury, parkinsonism, and postoperative psychiatric disturbances. The mean age of these patients was significantly higher than those with good recovery.(ABSTRACT TRUNCATED AT 250 WORDS)