Application of intraoperative MRI and microelectrode recording in deep brain stimulation of subthalamic nucleus for the treatment of Parkinson's disease

Abstract

Objective To investigate the value of intraoperative MRI (iMRI) and microelectrode recording (MER) in the deep brain stimulation (DBS) of subthalamic nucleus (STN) for the treatment of Parkinson＇s disease. Methods A total of 65 patients with Parkinson’s disease treated with STN-DBS were enrolled in this retrospective study including 54 cases of bilateral operations and 11 cases of unilateral operations. A total of 119 leads were implanted. The iMRI and 1-week postoperative MRI as well as intraoperative MER were applied. Results Two leads were found to be obviously deviated from the planned targets by iMRI and were then re-implanted. No intracranial hemorrhage was found by iMRI scanning. The MRI taken 1 week post operation showed that 50 of 119 (42.0%) leads were away from planned targets (1-2 mm) in X axis and Y axis and 12 (10.1%) leads were as deep as 3 mm in the z axis. Minor hemorrhage in 5 sides and localized brain edema in 14 sides were found near the lead tips. Obvious brain edema on 1 side was found surrounding the lead by the MRI taken 1 week post operation. In bilateral operation, the number of MER tracks at the first operation side (right) were 1~3 tracks (63 tracks in total), and the number of MER track at the posterior operation side (left) were 1~5 tracks (90 tracks in total) (P=0.018). There was no significant difference in start-up voltage and UPDRS-III improvement rate between different groups in terms of electrode deviation at 1 month after operation(P=0.964, P=0.130), and there was no correlation between electrode deviation and UPDRS-III improvement rate(r=0.006, P=0.968). There was a correlation trend between the electrode deviation and the start-up voltage. Conclusions The techniques of iMRI and MER can be safely applied in DBS procedures. The iMRI could help discover apparent lead shift and complications timely and MER may facilitate the real-time fine adjustment of lead position. The electrode deviation of less than 2 mm might not affect the therapeutic effect, which, however, might needs higher stimulation voltage. Key words: Parkinson disease; Deep brain stimulation; Subthalamic nucleus; Magnetic resonance imaging; Microelectrode recording