INTRACEREBRAL CYSTS COMPLICATING VENTRICULAR NEEDLING IN HYDROCEPHALIC INFANTS: A CLINICO-PATHOLOGICAL STUDY.

SUMMARY In performing cerebral ventricular punctures in infants and young children, there is a special risk of the development of tracks and cysts within the brain substance. These lesions always develop in the path of the needle puncture. The investigation is based on (a) a review of the ventriculograms performed on a consecutive series of 336 infants suspected of hydrocephalus; and (b) examination of the brains of 114 infants who died of hydrocephalus, spina bifida or its complications. Of the second group, 50 infants had ventriculographic examinations during life and the ventriculographic appearances could be compared with those seen at necropsy. Finally, post-mortem ventriculography was performed in many of these infants. These investigations showed that at the site of a single ventricular tap a long, narrow track frequently developed in the brain substance, and in time such a track commonly expanded into a large cavity, even in the absence of further taps. In cases where multiple punctures were performed (for the treatment of pyogenic ventriculitis), large, multilocular, irregular cavities could be demonstrated radiologically and at necropsy. The incidence of such tracks and cavities, as shown on ventriculography, was very high, but their true incidence was much higher. This was shown at necropsy, when cavities were almost always present at the site of multiple punctures. The cavities persisted for several years after the ventricular punctures were made. The histology of the needle tracks and the cavities is described. It is postulated that these lesions are determined mostly by the presence of increased intracranial tension at the time of and after the intraventricular injection of air or antibiotics. RESUME Kystes intracerebraux consecutifs a une ponction ventriculaire chez lesjeunes enfants hydrocephaliques En affectuant des ponctions des ventricules cerebraux chez des nourrissons et des jeunes enfants on risque de provoquer le developpement de traces et de kystes a l'interieur de la substance cerebrate. Ces lesions se developpent toujours sur le trajet de l'aiguille. Cette etude est basee sur (a) une revue des ventriculogrammes effectues sur des series consecutives de 336 enfants suspects d'hydrocephalie, et (b) l'examen des cerveaux de 114 enfants morts d'encephalie, de spina bifida ou de ses complications. Dans le second groupe 50 enfants avaient subi des examens ventriculographiques au cours de leur existence, les traces ont pu en etre compares aux observations faites lors de l'autopsie. Finalement, des ventriculographies ont pu etre effectuees chez beaucoup de ces enfants post-mortem. Ces recherches ont montre qu'a l'emplacement d'une unique ponction ventriculaire une trace longue et etroite se developpait frequemment dans la substance cerebrale et d'ordinaire avec le temps cette trace s'etendait en une caviteetendue, meme en l'absence d'autres ponctions. Dans les cas ou des ponctions multiples etaient effectuees (pour le traitement de la ventriculite pyogene), on pouvait mettre en evidence par radiologic ou a l'autopsie de grandes cavites multiloculaires et irregulieres. La ventriculographie a revele la tres haute incidence de ces traces et de ces cavites, mais leur incidence reelle etait bien superieure; ceci est apparu a l'autopsie. Les cavites etaient toujours presentes a l'emplacement de ponctions multiples. Plusie annees apres la ponction ventriculaire les cavites persistaient encore. Les auteurs decrivent l'histologie des traces d'aiguille et des cavites. On a emit le postulat que ces lesions sont determinees principalement par l'accroissement de la tension intracrânienne au moment de l'injection intraventriculaire d'air ou d'antibiotiques et apres.