Fig 3.

Position of the frontal sections on Schaltenbrand and Wahren atlas along the antero-posterior axis.

Top, Digitized frontal section of the Schaltenbrand and Wahren atlas (Fp 3.0). The main cerebral structures are indicated.

Bottom left, Frontal anterior view of the left subthalamic nucleus obtained by superimposing the six frontal sections of the Schaltenbrand and Wahren atlas containing the subthalamic nucleus.

Bottom right, Sagittal obtained by a 92-degree rotation of the same six frontal contours of the subthalamic nucleus. Note that frontal contours are irregularly spaced from the anterior level Fa 2.0 to the posterior level Fp 7.0, and that there are fewer sections located at the level of the anterior part of the nucleus than at the posterior part.