Relation of false localizing signs and remote hyperaemia in patients with intracranial mass lesions.

Seventeen patients with intracranial mass lesions underwent rCBF measurements with the xenon-133 carotid injection technique. In 11 patients remote areas of hyperaemia were found. There was a relation between location of the remote hyperaemia and the site of the mass lesion. In 10 of 11 patients with remote hyperaemia autoregulation was focally lost, and in 5 of 7 patients there was focal impairment of arterial pCO2-reactivity. In 8 of 11 patients with remote hyperaemia false localizing signs were found, related to the hyperaemic areas. It is suggested that the remote hyperaemic areas may be the result of brain bulk shifting due to the mass lesion and represent the initial stage of brain herniation.