Deep brain stimulation in Parkinson’s disease: analysis of the variation in final stimulating lead placement based on multi-tract electrode recordings
Background: Deep brain stimulation (DBS) of the subthalamic nucleus (SNT) is a treatment modality for Parkinson’s Disease (PD). Either single central trajectory tract or multiple selected trajectory tracts based on microelectrode recordings (MER) are used for the placement of the final stimulating electrodes. This study aims to explore how many times trajectory tracts, other than the central tract are used for final lead placement.
Methods: Retrospective analysis of a randomly selected convenience sample of 24 subjects from patients who had DBS by a single neurosurgeon. After MRI and CT assessment, planning using a stereotactic frame for variable trajectory placement of temporary electrodes and MER that was the basis for site and tract selection for the final electrode placements used for DBS.
Results: Twenty four patients had 47 DBS electrodes placed: 1 unilateral and 23 bilateral. The central tract was used in 45 (95.75%) of these cases. The central trajectory tract accounted for 30 (63.83%), the anterior trajectory tract for 7 (14.89%), the medial tract for 5 (10.64%), the posterior for 4 (8.51%) and the lateral for 1 (2.13%) of final lead placements.
Conclusion: The results of this study based on the predicted best stimulating sites following MER show that alternates to the central trajectory tract are required in 37% of site placements. A comparative study exploring clinical benefit is required to assess if variable electrode trajectory placement based on accurate physiological measurements is superior to single central trajectory placement.