Sonographic evaluation of experimental hydrocephalus in kittens.

Real-time computed sonography was used to monitor ventricular size in kittens with experimentally induced hydrocephalus. Hydrocephalus was induced by cisternal kaolin injection in newborn kittens in order to study the effects of both hydrocephalus and subsequent ventriculoperitoneal shunting on the morphology of brain tissue. When severe hydrocephalus was achieved, marked physical and neurologic abnormalities were identified by the investigators. However, when milder degrees of hydrocephalus were achieved, no neurologic abnormalities could be detected and only subtle physical signs such as palpable sutures were seen. In order to know when to shunt the kittens (or when to sacrifice kittens in the nonshunted control group), we needed to quantitate milder degrees of hydrocephalus in vivo. Sonography is the technique of choice in evaluating human infants and children with hydrocephalus and open fontanelles [1 , 2]. We found sonography to be an acceptable technique in imaging the kittens with hydrocephalus. Although the fontanelle closes early and remains closed, sonography of the brain is possible in hydrocephalic kittens because of the development of soft spots in the coronal sutures. However, in kittens who have been successfully shunted, the soft spots close quickly and the brain is no longer accessible to sonographic evaluation. The purpose of this paper is to present our technique and findings regarding the capability of sonography as a research tool in the evaluation of the brain of normal kittens, as well as in kittens who have had hydrocephalus experimentally induced and treated by ventriculoperitoneal shunts.