[Stereotaxic technics in expanding lesions of the brain stem]

Stereotactic biopsies, according to the Talairach's system, define the histopathological data (nature, grading, spatial delimitation, evolutive potential) of brain stem lesions, precisely localized by computerized tomography scanner and magnetic resonance imaging. They are the more valued complement of the modern neuro-imaging and they prove the extreme polymorphism of theses lesions. According to this histological analysis and the volume of the lesions, it's possible to choose the best therapeutic procedure.