[History of stereotaxis]

The concept of stereotaxy is essentially based on functional topography, which continuously evolved from the first observation by Hippocrates of a motor deficit contralateral to an hemispheric wound, to the characteristic example of Broca's speech area. The fate of a method depends on the need for it. When an outsider phenomenon, such as a pharmacological newcomer, occurred, which brought, at least for a given period, a satisfactory solution, the need for the method disappeared and sent it in oblivion. At the same time, the understanding that some pathologies, such as brain tumors, were not adequately taken care of by classical surgery and could eventually respond correctly to general treatments, such as chemotherapy or radiotherapy, induced the application of this forgotten, or near to be abandoned, method to a totally new field: this is what Talairach and his associates did when they introduced the stereotactic biopsy, at a time where movement disorders needed less surgery as levodopa had come and provided a very attractive treatment. When, on the contrary, it appeared that some forms of Parkinson's disease less responded to the drugs or were plauged by motor fluctuations and dyskinesias, there could be a new need for surgery. However, complications became at that time unacceptable and the method was required to evolve towards new directions where efficacy goes with a negligible morbidity. This led eventually to new developments such as brain grafting or more recently high frequency deep brain stimulation. Stereotaxy, like other methods, has experienced this type of fluctuation in its history and has on each occasion progressed and acquired new skills and possibilities, far beyond what it was initially designed for.