Abstract
A study was done on responsible factors in 170 elderly patients with chronic subdural hematoma (chronic SDH) who were over 65 years old. They were operated during the three years from 1986 to 1988. Burr-hole craniotomy and external drainage of the subdural collection was mostly accepted todays as the rational approach to this chronic SDH. The result was generally excellent.
CT-findings of chronic SDH, which was classified into the 4 groups, revealed the combind type (34.7%) and other types presented more or less than 20 percent. The factor most strongly affecting the prognosis was considered to be the presence of cerebral atrophy. But brain re-expansion was not always correlated with the prognosis. This unexpected result may be attributed to the difference between cerebral atrophy and cerebral elasticity. Other factors seemed to include disappearing time of residual air in the hematoma cavity and neurological grade on admission.
There were some cases of chronic SDH resulting from subdural hygroma (11.8%) and acute subdural hematoma (3.5%). Out of our elderly patients, 7 cases (4.1%) showed re-currence of symptoms due to reaccumulation of hematoma 2 or 3 months after the operation. As to the factors promoting chronic SDH, there was a tendency to increased incidence in patients with cerebral atrophy who had the head injury. Other factors showed low rate in patients with cerebral atrophy, and head injury.
From these results, these elderly patients might have the cerebral atrophy to some extent, and will increase frequently the chance to meet with head trauma. Then, it seems to be reasonable to think that elderly patients have slightly abnormal coagulation-fibrinolysis system and systemic cancer. Therefore, this would contribute to increase patients with chronic SDH.
