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The current state of postoperative imaging in the presence of deep brain stimulation electrodes
Author(s) -
Gilmore Greydon,
Lee Donald H.,
Parrent Andrew,
Jog Mandar
Publication year - 2017
Publication title -
movement disorders
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.352
H-Index - 198
eISSN - 1531-8257
pISSN - 0885-3185
DOI - 10.1002/mds.27028
Subject(s) - medical school , university hospital , general hospital , medicine , psychology , pediatrics , medical education , family medicine
For more than a decade, medically refractory movement disorders have been treated with deep brain stimulation (DBS) devices. Bilateral DBS of the subthalamic nucleus (STN), globus pallidus, and thalamus have been effective in reducing the complications of medications in later-stage movement disorder patients. However, the effectiveness of the DBS device is highly dependent on the proper radiologic and electrophysiological identification of DBS target structures and the accurate placement of the DBS electrodes. The reasons for suboptimal results from DBS surgery could be related to several factors such as patient selection (preoperative), precision of DBS electrode placement (intraoperative), and inadequate device programming and follow-up (postoperative). It should be mentioned from the outset that, regardless of the target, the issues of postoperative MRI in the presence of electrodes hold true. Limited clinical improvement from DBS therapy may result from misplaced electrodes during the intraoperative procedure. Magnetic resonance imaging (MRI) of DBS electrodes is the preferred method for confirming the anatomical location of electrodes given the amount of detail obtained. Recently, computerized topography (CT) has been used for electrode localization by fusing the postoperative CT with the preoperative MRI. This method could introduce more error given the fusion process required (eg, brain shift, CT air pockets). There is an implicit need for the localization of DBS electrodes with a postoperative MRI, and no amount of experienced DBS programming can compensate for a poorly placed electrode. Furthermore, a CT scan cannot replace invaluable MRI scan sequences that are used for diagnostic purposes (outside electrode localization). However, the current restrictions on the postoperative MRI of electrodes has resulted in many centers opting out of the procedure. Importantly, although the potential danger imposed by MRI scanning in the presence of electrodes should not be disregarded, the fear of such procedures should not impact patient care. The current viewpoint will assume that MRI scanning is being performed with both the leads and implantable pulse generator in place. Regardless of the patient, treating neurologist, or the implantation technique, postoperative MRI scanning is invaluable for proper electrode placement verification and diagnostic applications.