[Problem of the angiographic demonstration of subdural empyema in the interhemispheric cleft]

List's falx syndrome is confirmed on the basis of an analysis of six own patients and of a survey of the literature on 16 cases of interhemispheric empyemas. The angiographic diagnosis of interhemispheric empyemas is uncertain, and this is in contrast to opinions expressed in the literature. Negative angiographic results cannot be considered to rule out the possibility of the presence of an empyema in the interhemispheric space. In those cases in which corresponding clinical evidence is available it is recommended to always surgically explore the interhemispheric space subsequent to broad trephination.