Abstract
During two and a half years since the introduction of a CT scanner in February, 1977, 38 patients with traumatic subdural hygroma (SD hygroma) and 42 patients with chronic subdural hematoma (chronic SDH) were experienced.
Clinical symptoms and CT findings in SD hygromas were studied. Intensity of the head injury and appearance of the clinical symptoms in both conditions were compared, and the possibility of the development of chronic SDH from SD hygromas was studied. Clinical symptoms, such as headache and decreased spontaneity, occurred more often in patients with SD hygroma after head injury. Surgical treatment was necessary for patients who had disturbances of consciousness and an increased intracranial pressure (five cases). However, most patients improved with conservative therapy (33 cases). Bilateral SD hygromas were seen more frequently in older patients (over 60 years old). Low density areas in the CT decreased or disappeared in 23 out of 38 SD hygroma patients. In nine patients, the low density area remained as it was. In two patients, low density changed to high density and then disappeared. In four patients SD hygroma changed to chronic SDH 50, 70, 71, 72 days after the head injury respectively. Initial unconsciousness and skull fracture were more severe in SD hygroma than in chronic SDH. A long term asymptomatic state was observed in chronic SDH, but nine out of 42 chronic SDH patients had clinical symptoms from a few days after head injury.
From the clinical features, it seemed that SD hygroma was an entity distinct from chronic SDH. However, it was also thought that SD hygroma was a factor in the development of chronic SDH.
