Subthalamic nucleus stimulation in Parkinson's disease: Correlation of active electrode contacts with intraoperative microrecordings

Background/Aims: The most effective site for subthalamic nucleus (STN) stimulation has remained unclear. The position of active contacts relative to the dorsal margin of the STN was determined. Methods: Electrodes (n = 49) were implanted following STN mapping by microrecording and microstimulation along five tracks ( n = 25 patients). The stereotactic position of active contacts was determined and correlated with microrecordings using an algorithm for direct three-dimensional comparisons ( n = 37). Results: Most active contacts were detected within +/-1.0 mm from the dorsal margin of the STN as defined by microrecording (32.4%) or farther dorsal in the subthalamic area (37.8%), and only 29.7% were localized to the STN proper. This was consistent with the average stereotactic coordinates of the active contacts in these three groups. Conclusion: Our data suggest that the dorsal border area of the STN is the most effective target. Besides the dorsolateral STN ( sensorimotor part) this may include projections from/ to STN, the zona incerta, and pallidofugal projections in the fields of Forel. Copyright (C) 2003 S. Karger AG, Basel.