Elsevier

World Neurosurgery

Volume 107, November 2017, Pages 900-905
World Neurosurgery

Original Article
Microelectrode Recording–Guided Versus Intraoperative Magnetic Resonance Imaging–Guided Subthalamic Nucleus Deep Brain Stimulation Surgery for Parkinson Disease: A 1-Year Follow-Up Study

https://doi.org/10.1016/j.wneu.2017.08.077Get rights and content

Background

Microelectrode recording (MER) and intraoperative magnetic resonance imaging (iMRI) have been used in deep brain stimulation surgery for Parkinson disease (PD), but comparative methodology is lacking. Therefore, we compared the 1-year follow-up outcomes of MER-guided and iMRI-guided subthalamic nucleus (STN) deep brain stimulation (DBS) surgery in PD patients.

Methods

We conducted a review comparing PD patients who underwent MER-guided (n = 76, group A) and iMRI-guided STN DBS surgery (n = 61, group B) in our institution. Pre- and postoperative assessments included Unified Parkinson's Disease Rating Scale-III (UPDRS-III) score, Parkinson's Disease Questionnaire (PDQ-39), Mini-Mental State Examination (MMSE), levodopa equivalent daily doses (LEDDs), and magnetic resonance images.

Results

The mean magnitudes of electrode discrepancy were x = 1.1 ± 0.2 mm, y = 1.3 ± 0.3 mm, and z = 2.1 ± 0.5 mm in group A and x = 1.3 ± 0.4 mm, y = 1.2 ± 0.2 mm, and z = 2.5 ± 0.7 mm in group B. Significant differences were not found between 2 groups for x, y, or z (P = 0.34, P = 0.26, and P = 0.41, respectively). At 1 year, when levodopa was withdrawn for 12 hours, the UPDRS-III score improved by 66.3% ± 13.5% in group A and 64.8% ± 12.7% in group B (P = 0.24); the PDQ-39 summary index score improved by 49.7% ± 14.3% in group A and 44.1% ± 12.7% in group B (P = 0.16); the MMSE score improved by 4.2% ± 2.1% in group A and 11.1% ± 3.2% in group B (P = 0.43); and LEDDs decreased by 48.7% ± 10.1% in group A and 56.9% ± 12.0% in group B (P = 0.32).

Conclusions

MER and iMRI both are effective ways to ensure adequate electrode placement in DBS surgery, but there is no superiority between both techniques, at least in terms of 1-year follow-up outcomes.

Introduction

Parkinson disease (PD) is a progressive neurodegenerative disorder characterized by resting tremor, rigidity, bradykinesia, and postural disturbances.1 Although these motor symptoms can initially be controlled with levodopa and other dopaminergic drugs, long-term drug effects will become worse and worse, and complications may occur, such as on/off motor fluctuations and dyskinesias.1, 2 Subthalamic nucleus (STN) deep brain stimulation (DBS) is an established treatment for advanced PD.2, 3, 4 Not only does it improve motor symptoms, but it also reduces the severity of dyskinesias and at the end might improve patient's quality of life. Moreover, some researchers consider DBS to be beneficial for patients who are at earlier stages of PD.1, 5 There is no doubt that the success of DBS mostly depends on the accuracy of the DBS electrodes. There are many factors leading to the discrepancies between the planned optimal targets and the final DBS locations: imaging distortion, operational errors, mechanical inaccuracy of the stereotactic system, and brain shift.6, 7, 8, 9 Although there have been some models and algorithms described, specific factors leading to electrode displacement are lacking.7, 10, 11

Many researchers deem that physiologic refinement with microelectrode recording (MER) is the gold standard to identify the borders of the STN, and sufficient physiologic activities are easily obtained with proper targeting in most patients.12 MER has been widely used in DBS surgery for PD, but it is still controversial whether it should be used to improve localization and identification of the STN region because of its drawbacks. At the same time, protocols without MER are adopted by more and more surgical centers.13, 14, 15 To our knowledge, the randomized controlled trials comparing approaches of the MER-guided and intraoperative magnetic resonance imaging (iMRI)–guided DBS surgery for PD patients in a single center have not yet been reported.

We present our own institution's experience of MER-guided and iMRI-guided STN DBS in a series of PD patients, trying to find an alternative for patients unable or unwilling to undergo MER-guided DBS surgery.

Section snippets

Patient Population

We retrospectively examined a total of 137 PD patients being treated in our PD research center between January 2012 and April 2016 ranging in age from 43 to 76 years (mean, 62 ± 7.69 years). They were followed-up for at least 1 year postoperatively. These patients were divided into 2 groups: group A included 76 patients whose implantations were guided by MER, and group B included 61 patients whose implantations were guided by iMRI. All patients were assessed preoperatively and 1 year

Results

There were 76 patients in group A (43 men and 33 women; mean age, 62 ± 7.7 years) whose STN DBS was conducted with MER and 61 patients in group B (30 men and 31 women; mean age, 63 ± 4.5 years) whose STN DBS was conducted with iMRI. Baseline characteristics were similar between the 2 groups. In group A, the total number of electrodes was 141 and 113 in group B. The mean Hoehn-Yahr stage was 3.1 ± 1.0 (range, 2.5–5) for group A and 3.2 ± 0.6 (range, 2.5–5) for group B (Table 1). Groups A and B

Discussion

The small-size surrounding nuclei and nerve fiber tracts and individual anatomic variability of STN make stereotactic accuracy difficult. Brain shift is a major drawback of DBS that relies on preoperative imaging because the deformation of the brain tissue occurs with dynamic conditions during surgery. It is sometimes difficult to achieve the desired location of the target by only 1 trajectory.

Most centers currently use MER to identify the characteristic neuronal firing patterns during surgery.

Conclusions

There is no obvious reason to conclude that one technique is superior to the other as far as 1-year motor, neuropsychologic, and levodopa equivalents follow-up outcomes are concerned, along with complications. iMRI-guided DBS is a feasible option for PD patients unable or unwilling to undergo MER-guided DBS surgery. Moreover, the increase in surgical risk of intracranial hemorrhage correlated with the increase of microelectrode trajectory should be considered related to MER technique.

References (27)

  • C. Nimsky et al.

    Quantification of, visualization of, and compensation for brain shift using intraoperative magnetic resonance imaging

    Neurosurgery

    (2000)
  • S. Pallavram et al.

    A method to correct for brain shift when building electrophysiological atlases for deep brain stimulation (DBS) surgery

    Med Image Comput Comput Assist Interv

    (2009)
  • A. Umemura et al.

    Validity of single tract microelectrode recording in subthalamic nucleus stimulation

    Neurol Med Chir (Tokyo)

    (2013)
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    Conflict of interest statement: All study costs were covered by the Parkinson's Disease Research Center of Wuhan University Zhongnan Hospital.

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