Principles of Stereotaxy

Abstract

There are few parts of the body, which may not be approached by means of a surgical operation. An exception to this rule is the deep parts of the brain. The reasons are easy to understand. The head is a rigid cavity and about 90% by volume of its contents is cerebral tissue. This tissue tolerates retraction and displacement badly. Moreover, access to, for example, the basal ganglia involves an unavoidable and unacceptable risk of damage to eloquent areas lying superficial to or adjacent to these ganglia. Thus, conventional open surgical techniques are an essentially inappropriate method to use for operations in the depths of the brain, irrespective of the sophistication of modern microsurgical techniques. These problems have been appreciated for a long time. A solution, at least in principle, has also been around for a long time, in fact since before the First World War.