Ventriculography

VENTRICULOGRAPHY (from Latin ventriculus-ventricle and Greek grapho-I write), a method of X-ray examination of the brain's ventricles after filling them with air. With the help of this method, it is possible, on one hand, to determine whether the normal communication pathways of the cerebrospinal fluid are preserved, and on the other hand, to ascertain the condition of the ventricles. When the foramen of Monro is closed, air cannot penetrate into the opposite ventricle, and in such cases, the operation must be repeated on the opposite side. V. makes it possible to determine the size of the ventricles, their deformation, displacement, etc., and also reveals the presence of cysts. Some authors consider V. a synonym of encephalography (see), which is incorrect; most authors make a distinction between these terms. V. was proposed in 1918 by the American surgeon Dandy. After trepanation in the area of the anterior or posterior horn of one of the lateral ventricles, a needle is inserted into the brain, directed toward one or the other horn, and the cerebrospinal fluid is aspirated with a Rekord syringe, in place of which the same amount of air or another indifferent gas is insufflated. By repeating the procedure several times, a significant portion of the fluid can be replaced with air. On the X-ray films made afterward, the lateral ventricles are clearly visible. On the fronto-occipital film, they have the figure of a butterfly, formed by the shadows of the anterior horns and the middle part of the ventricles. Below and outward from it, the ventricular triangles are visible, and further back, the posterior and inferior horns. On the midline, directly under the butterfly, the third ventricle is visible in the form of an oval or a slit. On the occipito-frontal film, the configuration of the ventricles changes, and the greatly flattened posterior horns protrude sharply. On the lateral films, the anterior, posterior, and inferior horns, as well as the middle part and the ventricular triangle, are clearly visible [see separate table (pp. 351-352), figs. 1 and 2]. The third and fourth ventricles, as well as the aqueduct of Sylvius, are not visible in normal conditions; but in some pathological conditions (meningitis) that cause ventricular dilation, they are sometimes, especially in children, clearly visible; the third ventricle is projected onto the thalami as a square with rounded corners, and the fourth as a triangle located above the pyramids of the temporal bones and with its apex directed backward. When a sufficient amount of air is introduced, part of it spreads into the cisterns and subarachnoid spaces, as a result of which the cerebral convolutions become visible. The application of V. is indicated for brain tumors, especially of the posterior fossa; sometimes V. makes it possible to precisely localize the tumor where ordinary clinical research does not. Dandy, Jungling, and others use almost exclusively this method; most authors, however, regard V. as a method that complements encephalography, and resort to it either when, during encephalography, air did not penetrate into the ventricles (closure of the foramina of Majandi and Luschka or the aqueduct of Sylvius, or the third ventricle and the foramina of Monro), or when there is suspicion of a tumor in the posterior fossa. Initially, oxygen was used as the gas; now almost everyone uses ordinary air. The introduction of air into the brain almost always entails certain consequences. The most frequent of these are headache and elevated temperature. Vomiting, dizziness, slowing of the pulse, profuse sweating, etc., are not uncommon, and sometimes fatal outcome; initially the number of such cases was quite large (up to 20 percent in some authors), but now they are observed less and less frequently, due to greater caution in the choice of material. In autopsies of those who died from V., a picture of death from paralysis of the respiratory center is usually found, which can be explained by the effect of the introduced air on the medulla oblongata. Sometimes multiple small punctate hemorrhages or an apoplectic focus are found in the brain. Complications pass rather quickly (within two to three days), but in cases where absorptive capacity is reduced and the air is not absorbed for a long time, complications may be prolonged. Severe consequences are usually not left behind by ventriculography (for more details, see Encephalography). Lit.: V r u s k i n Y. M. and F r e n k e l l R., Latest methods of X-ray diagnosis, M., 1928; literature is given in detail in the work W a g-t e n b e r g R., Encephalographische Erfahrungen, Zeitschrift für die gesamte Neurologie u. Psychiatrie, B. XCIV, 1925; Jiing ling O., Ventrikulographie bzw. Enzephalographie im Dienste d. Diagnostic v. Erkrankungen d. Gehirns, Ergebnisse d. medizinischen Strahlenforschung, B. II, 1926.