Schaltenbrand Definition in Neurology
The Schaltenbrand-Wahren atlas is a stereotactic brain atlas of the human diencephalon and basal ganglia, created from microscopic anatomical sections and used primarily for anatomical targeting in functional neurosurgery, particularly for procedures like thalamotomy, pallidotomy, and deep brain stimulation. 1, 2
Historical Context and Development
- Georges Schaltenbrand was a prominent German neurologist (1897-1979) who made significant contributions to stereotactic neurosurgery 3
- The "Atlas for Stereotaxy of the Human Brain" was authored by Schaltenbrand and Wahren and published in 1977, remaining a standard reference in stereotactic surgery for decades 1, 3
- The atlas was created in collaboration with American neurosurgeon Percival Bailey, with an earlier version published in 1959 3
Anatomical Structure and Composition
- The atlas consists of three separate microscopic series: sagittal, coronal (frontal), and horizontal (axial) sections 1, 4
- A critical limitation is that these three series were derived from three different cerebral hemispheres, meaning anatomically corresponding points with identical AC-PC (anterior commissure-posterior commissure) coordinates do not represent exactly the same anatomical location across series 4
- The sagittally sectioned thalamus is approximately 10% larger than the frontally sectioned and 40% larger than the horizontally sectioned thalamus 4
Clinical Applications in Functional Neurosurgery
The atlas is used for precise anatomical targeting in procedures including:
Modern usage involves digitizing the printed atlas microseries, extending them to cover both hemispheres, and creating electronic versions that can be coregistered with patient imaging data 1
Registration and Targeting Methodology
- Electronic versions are interactively registered with patient data using the three-dimensional Talairach proportional grid system transformation 1
- Local warping in the region of interest is performed based on clearly visible anatomical landmarks 1
- Co-registration with probabilistic functional atlases (PFA) is achieved by matching AC-PC distances and thalamic heights 2, 5
- Linear scaling is applied along the intercommissural distance and thalamic height to align anatomical and functional data 5
Spatial Inconsistencies and Corrections
- To match the frontal series to the sagittal series, the frontal series must be widened laterally by 19%, compressed anteroposteriorly by 5%, and compressed vertically by 9% 4
- The horizontal series is 25% smaller than the sagittal series in anteroposterior direction and 17% smaller in vertical direction 4
- Spatial overlap between corresponding thalamic nuclei from the three series amounts to only 0-28% when superimposed in AC-PC reference space 4
- Linear transformation toward an average increases overlap to 0-37%, significantly improving the quality of fit 4
Advantages of Modern Multi-Atlas Approaches
- Combining the Schaltenbrand-Wahren atlas with probabilistic functional atlases leverages anatomical detail with electrophysiological data 5
- The combined approach displays high-resolution functional structures while providing surrounding anatomical context from the Schaltenbrand atlas 5
- For subthalamic nucleus targeting, the horizontal and lateral coordinates are approximately the same between anatomical and functional targets, but the functional target is located 1.3-1.5 mm more anteriorly 5
Common Pitfalls
- Do not assume that identical AC-PC coordinates represent the same anatomical location across the three microscopic series - they were derived from different brains 4
- Failing to account for the size differences between series can lead to targeting errors of several millimeters 4
- Using the atlas without modern co-registration techniques and electronic interpolation limits accuracy 1, 2
- Relying solely on the Schaltenbrand-Wahren atlas without incorporating functional data from electrophysiology or modern imaging may reduce targeting precision 5