Cerebral Blood Flow in Normal Brain Tissue of Patients with Intracranial Tumors

Abstract

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.

Proton MRS of the peritumoral brain

“…Growing intracranial neoplasm exhibits various effects on the peritumoral brain, such as accumulation of the edematous fluid, hypoperfusion with or without ischemia, local inflammation and diffusion of the metabolically active substances secreted by the lesion itself [1][2][3]. Any of these, in association or separately, may contribute to neuronal dysfunction.…”

Metabolic alterations in the peritumoral brain in cases of meningiomas: 1H-MRS study

“…Invasive growth and prominent peritumoral edema are more frequently observed in larger tumors with greater compressive effect on the adjacent cerebral structures [18][19][20]. Peritumoral alterations of the cerebral blood flow with or without ischemia caused by mass-effect of the neoplasm and accumulation of the edematous fluid are not uncommon in cases of intracranial meningiomas [21][22][23][24][25]. All these pathophysiological and associated histopathological abnormalities, which are presented in the "transitory zone" between the tumor border and normal brain, can be reflected in changes of 1 H-MRS-detected metabolite content.…”

Localization of somatosensory function by using positron emission tomography scanning: a comparison with intraoperative cortical stimulation

“…This suggested that failure to attain statistical significance was due to the limited number of task repetitions and variability in tracer uptake and not to abolition of the blood flow response because of destruction or compression of the cortex by the mass lesion. 15 Hence we examined the correlation between the value of the t statistic peak and the results of ICS and determined t-statistic ranges that predicted the results of ICS more accurately than the simple presence or absence of statistically significant activation. We found that when there is absent or weak PET activation (t Ͻ 3.2), ICS is invariably negative and unnecessary.…”