PATHOGENETIC FACTORS IN CHRONIC SUBDURAL-HEMATOMA AND CAUSES OF RECURRENCE AFTER DRAINAGE

The radiological aspect, pathology, treatment and results of 132 subdu ral haematomas observed in 100 patients, are discussed. The majority o f these cases were characterized by a nonhomogenous CT scan picture, r esulting from repeated bleeding in a previous subdural haematoma evolv ing to chronicity, or in a pre-existent subdural hygroma. Taking aspir in may have constituted a predisposing factor in 16% of our patients, whilst coagulation disturbances, including anticoagulant treatment, we re observed in another 6%; ethylism was present in 11%. A traumatic or igin was ascertained in 80% of the patients. The treatment consisted o f burr hole evacuation and drainage in 91.5% of the haematomas, corres ponding to 99% of the patients; it was eventually repeated once or twi ce in some cases. In 6% of the patients, a subduro-peritoneal drainage had to be placed ultimately and in 2%, a membranectomy had to be perf ormed because the haematoma had become nearly completely fibrous. The necessity for repeated evacuation and eventual subduro-peritoneal drai nage seems to depend mainly on a slow brain re-expansion in some elder ly people, who are actually more frequently referred. Two patients die d; one was deeply comatose and another in poor general condition. Morb idity in the 96 remaining patients, 2 being lost to follow-up, was 11% : 5% related to the haematoma or to the causal trauma, and 6% from oth er concomitant neurological disease. The functional result was satisfa ctory in 85%.