Determination of intracerebral structures using osseous reference points for computer-aided stereotactic operations.

Computer-aided sterotactic neurosurgery can be improved and simplified by using craniocerebral parameters for the calculation of subcortical target points and avoiding an air-filling of the ventricles. This was achieved by selecting 403 pneumo-encephalographic studies at random, measuring the craniocerebral parameters according to age and sex. There is a correlation between the bony cranium and the brain axis. We established a formula and a table to determine in the plain X-ray the entrance of the foramen of Monroi with a standard deviation of +/- 1.5 mm and the inclination of the intracerebral basic line we used (foramen Monroi-commissura posterior). With this information various subcortical targets can be determined by means of computer programs.