Microelectrode-guided functional neurosurgery assisted by Electronic Clinical Brain Atlas CD-ROM

The Electronic Clinical Brain Atlas is a CD-ROM containing several classic brain atlases and a real-time yet simple registration function that deforms the atlases to match them with specific patient studies. This article presents the use of this registration function for functional neurosurgery planning. We first propose the CD-ROM assisted planning procedure, then illustrate it with two cases: a pallidal stimulation and a thalamic stimulation. The Schaltenbrand-Wahren atlas is registered and scaled to conform with an actual patient's data by means of two-dimensional (2-D) local deformations performed in multiple orientations. First a rectangular region of interest (ROI), which is set between any clearly visible landmarks chosen by the neurosurgeon, is measured on the film or scanner console. The corresponding atlas plate with the target is then deformed in real time for the same landmarks, such that the dimensions of this ROI are the same on the film and on the deformed atlas plate. Next the target is set on the deformed (individualized) atlas plate and its coordinates are read. The individualized atlas plate can also be printed on transparent foil and superimposed on the film or, alternatively, this superimposition can be done electronically. The planning steps can be repeated for all available orientations. The proposed atlas-assisted planning procedure extends the traditional use of printed stereotactic atlases by individualizing them to specific patients. The preliminary results show that this procedure may improve the definition of the target and may have several advantages over other approaches, such as indirect measurements based on the AC-PC line or 1-D (intercommissural distance based) scaling. It provides the neurosurgeon with a convenient and immediate means of accessing ancillary data that is usually only available in the printed form.