Comparison of subthalamic nucleus borders determined by high-resolution MRI and microelectrode recording

Background. Deep brain stimulation (DBS) of the subthalamic nucleus (STN) is an acknowledged efficient and safe method of treatment of advanced stages of Parkinson’s disease. The traditional way of intraoperative target verification is a combination of microelectrode recording (MER) and intraoperative macrostimulation. The appearance of high-field tomographs, new sequences, and methods of computer processing of the obtained images raises the question whether it’s necessary to use intraoperative verification of the target.
Objective. The aim of the study was to analyze the comparability of 3T MRI data and microelectrode registration data in determining the boundaries of the subthalamic nucleus in patients with Parkinson's disease.
Material and methods. 20 patients who have been undergone 3T MRI for preoperative planning for STN-DBS were included in the study. We determined the upper and lower boundaries of 40 subthalamic nuclei in high-resolution T2 and SWAN modes and compared these data with the data obtained during surgery using the MER.
Results. The discrepancy between the MED and 3T MRI data when determining the upper STN border was 1.2 mm in SWAN mode and 1 mm in high-resolution T2 mode. The lower border of the subthalamic nucleus could be determined with an accuracy of 0.85 in SWAN mode and 0.75 mm in T2 mode. The groups didn’t have significant differences (Wilcoxon sign-rank test, p > 0.05).
Conclusion. 3T MRI in high-resolution T2 and SWAN modes demonstrated high comparability with microelectrode data in determining the upper boundary, lower boundary and middle of the subthalamic nucleus, which makes it possible to use it as a method for direct STN imaging.

1. Kerl H.U., Gerigk L., Pechlivanis I. et al. The subthalamic nucleus at 3.0 Tesla: choice of optimal sequence and orientation for deep brain stimulation using a standard installation protocol: clinical article. J. Neurosurg. 2012; 117 (6): 1155–1165. https://doi.org/10.3171/2012.8.JNS111930

2. Lefranc M., Zouitina Y., Tir M. et al. Asleep Robot-Assisted Surgery for the Implantation of Subthalamic Electrodes Provides the Same Clinical Improvement and Therapeutic Window as Awake Surgery. Wld Neurosurg. 2017; 106: 602–608. https://doi.org/10.1016/j.wneu.2017.07.047

3. Chandran A.S., Bynevelt M., Lind C.R. Magnetic resonance imaging of the subthalamic nucleus for deep brain stimulation. J. Neurosurg. 2016; 124 (1): 96–105. https://doi.org/10.3171/2015.1.JNS142066

4. Cheng C.H., Huang H.M., Lin H.L., Chiou S.M. 1.5T versus 3T MRI for targeting subthalamic nucleus for deep brain stimulation. Br. J. Neurosurg. 2014; 28 (4): 467–470. https://doi.org/10.3109/02688697.2013.854312

5. Longhi M., Ricciardi G., Tommasi G. et al. The Role of 3T Magnetic Resonance Imaging for Targeting the Human Subthalamic Nucleus in Deep Brain Stimulation for Parkinson Disease. J. Neurol. Surg. A. Cent. Eur. Neurosurg. 2015; 76 (3): 181–189. https://doi.org/10.1055/s-0033-1354749

6. Duchin Y., Abosch A., Yacoub E. et al. Feasibility of using ultra-high field (7 T) MRI for clinical surgical targeting. PLoS One. 2012; 7 (5): e37328. https://doi.org/10.1371/journal.pone.0037328

7. van Laar P.J., Oterdoom D.L., Ter Horst G.J. et al. Surgical Accuracy of 3-Tesla Versus 7-Tesla Magnetic Resonance Imaging in Deep Brain Stimulation for Parkinson Disease. Wld Neurosurg. 2016; 93: 410–412. https://doi.org/10.1016/j.wneu.2016.06.084

8. O'Gorman R.L., Shmueli K., Ashkan K. et al. Optimal MRI methods for direct stereotactic targeting of the subthalamic nucleus and globus pallidus. Eur. Radiol. 2011; 21 (1): 130–136. https://doi.org/10.1007/s00330-010-1885-5

9. Illarioshkin S.N., Konovalov R.N., Fedotova E.Yu., Moskalenko A.N. New MRI diagnostic methods in Parkinson's disease: evaluating nigral degeneration. Annals of Clinical and Experimental Neurology. 2019; 13 (4): 77–84. https://doi.org/10.25692/ACEN.2019.4.10 (In Russian)

10. Alkemade A., de Hollander G., Keuken M.C. et al. Comparison of T2*-weighted and QSM contrasts in Parkinson's disease to visualize the STN with MRI. PLoS One. 2017; 12 (4): e0176130. https://doi.org/10.1371/journal.pone.0176130

11. Dimov A.V., Gupta A., Kopell B.H., Wang Y. High-resolution QSM for functional and structural depiction of subthalamic nuclei in DBS presurgical mapping. J. Neurosurg. 2018; 131 (2): 360–367. https://doi.org/10.3171/2018.3.JNS172145

12. Rasouli J., Ramdhani R., Panov F.E. et al. Utilization of Quantitative Susceptibility Mapping for Direct Targeting of the Subthalamic Nucleus During Deep Brain Stimulation Surgery. Oper. Neurosurg. (Hagerstown). 2018; 14 (4): 412–419. https://doi.org/10.1093/ons/opx131

13. Polanski W.H., Martin K.D., Engellandt K. et al. Accuracy of subthalamic nucleus targeting by T2, FLAIR and SWI3-Tesla MRI confirmed by microelectrode recordings. Acta Neurochir. (Wien). 2015; 157 (3): 479–486. https://doi.org/10.1007/s00701-014-2328-x

14. Bus S., van den Munckhof P., Bot M. et al. Borders of STN determined by MRI versus the electrophysiological STN. A comparison using intraoperative CT. Acta Neurochir. (Wien). 2018; 160 (2): 373–383. https://doi.org/10.1007/s00701-017-3432-5

15. McEvoy J., Ughratdar I., Schwarz S., Basu S. Electrophysiological validation of STN-SNr boundary depicted by susceptibility-weighted MRI. Acta Neurochir. (Wien). 2015; 157 (12): 2129–2134. https://doi.org/10.1007/s00701-015-2615-1