Anatomical situation of the subthalamic nucleus (STN) from midcommissural point (MCP) in Parkinson\'s disease patients underwent deep brain stimulation (DBS): an MRI targeting study

  Abstract   Introduction: It is demonstrated that the degree of clinical improvement in   Parkinson's disease (PD) achieved by deep brain stimulation (DBS) is largely dependent   on the accuracy of lead placement. In addition, individual variability in the   situation of subthalamic nucleus (STN) is responsible for spatial inter-individual   fluctuations of the real patient's target.   Objective: Our study was aimed to identify the anatomic location of STN from   midcommissural point (MCP) in Iranian Parkinson's disease patients who underwent   DBS by means of a 3-dimentional magnetic resonance imaging (MRI).   Methods: Forty-six patients with the PD were recruied as candidates for bilateral   implantation of STN-DBS (92 subthalamic nucleuses) were recruited. All these patients   had bilateral implantation at the same operation. DBS and MRI parameters including   the target coordinates (X, Y, Z) and the distances from MCP to the center of   STN in all three axes on both sides were reported and calculated for each patient.   Results: The location of STN was approximated by a site with 11 mm lateral, 3 mm   inferior and 3 mm posterior to the midcommissural point. This distance was significantly   lower in PD patients who aged >50 years in both right and left sides in the Y-axis   direction.   Conclusion: Our findings led to a considerable set of information which could   help neurosurgeons during DBS procedure in Iranian PD patients. Despite the differences observed between various population of PD patients in the anatomical location of STN, our results further depicted the clustration of active contact points in same region.