[Study of intracranial dynamics by applying a water-soluble contrast medium, N-methylglucamine iothalamate, to the dog brain].

The water-soluble contrast medium, N-methylglucamine iothalamate (NMGI), when injected in a dose of 1 ml into the cerebral parenchyma space of dogs (Feldberg's method), diffused within the lateral ventricle at a constant rate of flow against the nerve fibers running therein. Such was recorded by X-ray television and 16 mm cinecamera. Injection of the same dose into the subarachnoid space, however, did not produce these phenomena. Differences in the mode of transfer from brain to heart as the result of three different sites of application (ventricle, parenchyma and subarachnoid space) were investigated using 131I labeled NMBI, the determination of radioactivity being made by two scintillation detectors situated at the head and the heart. The determination of RI activity revealed that the above mentioned three areas of brain have their own characteristic pattern of attenuation from brain to heart, particularly in the case of subarachnoid application. Clonic convulsions after intracranial administration of NMGI in dogs occurred when NMGI was given into the parenchyma but not when given into the ventricle.