Intracranial pressure gradients in a patient with a thalamic tumor.

The clinical history and intracranial pressure records of a patient with a thalamic tumor obstructing the ventricular system is presented. There were sustained differences in pressure between the anterior and posterior parts of the obstructed lateral ventricle. Brain compliance was markedly reduced and there were numerous pressure waves. It is believed that these supratentorial pressure gradients are most marked when there is a loss of brain compliance, and that they contribute to the mechanisms of brain shifts and spreading edema. Thus, they must be taken into account in the management of patients with intracranial mass lesions.