Histoenzymatic and permeability changes in human brain adjacent to meningioma.

Cerebral specimens were removed from ten patients with meningioma. Vascular permeability was tested with sodium fluorescein and a correlative study of the oxidative and hydrolytic enzyme activity was performed. Vascular permeability change was observed in half of the specimens of cortex taken from the region of the tumor. Labeled tracer diffusion was found to be either perivascular or involved microscopic ischemic areas. Fluorescein diffusion of the edematous white matter was observed in only two specimens. Enzyme activity in walls of the blood vessels was modified in the fluorescent specimens. Alkaline phosphatase and oxidoreductase activities were decreased. Experimental results have shown a relationship between increased vascular permeability and metabolic disorder of both vascular walls and cerebral cortex. Our findings agree with Zülch's hypothesis regarding a "hemodynamic" mechanism in the formation of edema by extraneural compression.