Cerebral blood flow in normal brain tissue of patients with intracranial tumors.

Pre- and postoperative cerebral blood flow (CBF) changes in the normal brain tissue of 17 patients with intracranial tumors were studied to determine the value for planning therapeutic strategy. The tumors included eight astrocytomas, seven meningiomas, one metastasis, and one arachnoid cyst. The patients were divided into two groups based on the mass effect seen on computed tomography (CT) scans. Group A comprised six patients with midline shift or evidence of herniation; Group B, 11 patients with no mass effect or local compression only. CBF and vasoresponse to acetazolamide were measured in the bilateral hemispheres, cortices, and thalami using xenon-enhanced CT, excluding the area of tumor extension, before and 2-3 weeks after tumor excision. Preoperative CBF was reduced bilaterally but more markedly ipsilateral to the tumor. The CBF reduction was significantly greater in Group A than in Group B. Acetazolamide caused CBF to increase by 70.5-99.1% in Group B but only increase by 1.7-9.6% or paradoxically decrease in Group A. Postoperatively, the CBF tended to recover partially in Group A but persisted or deteriorated in Group B. The more pronounced CBF reduction and poor or paradoxical response to acetazolamide preoperatively and postoperative CBF restoration in Group A may indicate that ischemia was more important than metabolic depression in these patients. In contrast, the excessive response to acetazolamide and the postoperative CBF deterioration in Group B may indicate that CBF reduction was secondary to metabolic depression. Mass effect is a key predictor for functional recovery following surgical decompression of intracranial tumors.