Unilateral subdural hematoma without midline shift.

Two cases of radiographically isodense subdural hematoma are presented in which absence of displacement of midline cerebral structures was due not to bilateral lesions, but rather to "balancing" of the volumetric effect of a unilateral lesion by preexisting encephalomalacia. Attention to the past medical history and the computed tomography scan which showed evidence of unilateral loss of brain substance led to the proper diagnosis.