Background: Identification of the subthalamic nucleus (STN) on MR images is difficult, and the use of external landmarks could be of interest for STN targeting in deep brain stimulation (DBS).
Objectives: Our aim was to explore the relationship between the anteroposterior coordinates of (1) the center of the mamillothalamic tract and (2) the anterior border of the STN on axial MR images.
Patients and methods: The brains of 16 healthy volunteers were imaged on a 3T MR system. Four millimeters under the anterior-posterior commissure plane, we noted the y coordinates of (1) the center of the mamillothalamic tract and (2) the anterior border of the STN.
Results: The coordinates were y(STN) = 14.7 ± 1.23 mm and y(Tmth) = 14.3 ± 1.13 mm from the posterior commissure for the STN and the mamillothalamic tract, respectively. The mean difference was 0.4 mm (range 0-1 mm). Pearson's coefficient was 0.97 (p < 0.01).
Conclusion: We observed a strong correlation between the anteroposterior coordinates of the mamillothalamic tract and the anterior border of the STN (which is located between 0 and 1 mm in front of the mamillothalamic tract). The mamillothalamic tract could be a good anterior landmark for STN targeting. It could also be tested for target determination in DBS for severe obsessive-compulsive disorder.
Copyright © 2011 S. Karger AG, Basel.