Article
Deep brain stimulation for Parkinson’s disease: anatomical location of effective contacts in the subthalamic area
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Published: | May 4, 2005 |
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Outline
Text
The location of effective contacts during deep brain stimulation (DBS) is still debated, especially in the subthalamic area.
Objectives:
To localise on 1,5 T MRI the effective contacts in patients successfully treated for Parkinson's disease by bilateral DBS of the subthalamic nucleus (STN).
Material / Methods:
Ten patients with excellent clinical outcome were analysed. The surgical procedure was based on direct targeting of the nucleus (anatomic targeting without reference to internal landmarks). The effective contacts, i.e. those giving the best efficacy on the clinical symptoms (mean improvement rate 82,5%, range 75,8-94,1%), were determined during the first six months following the implantation. The contact locations were retrospectively projected on the stereotactic 1,5 T MRI (3 sets, orthogonal plans), i.e. with a stereotactic frame. For each patient, we distinguished the right and the left hemisphere. The location of the effective contacts was directly studied by visual comparison between the 1,5 T images and an in-house 4,7 T MRI anatomic reference. The membership for a given structure was determined using the results for each orthogonal, independent plane.
Results:
The effectice contacts were located within the STN in 4 cases, at the interface of the STN and The zona incerta (ZI) and / or Forel's field (FF) in 12 cases, at the interface between ZI and FF in 3 cases, at the interface between STN and substantia nigra in 1 case.
Discussion:
The dorso-lateral part of the STN is usually considered as the target for DBS in Parkinson's disease. We discuss the role of adjacent structures, especially ZI and FF, in the clinical benefit.