gms | German Medical Science

59th Annual Meeting of the German Society of Neurosurgery (DGNC)
3rd Joint Meeting with the Italian Neurosurgical Society (SINch)

German Society of Neurosurgery (DGNC)

1 - 4 June 2008, Würzburg

Influence of microelectrode recording (MER) and test stimulation on definite electrode position in subthalamic nucleus (STN) deep brain stimulation (DBS) for Parkinson's disease (PD) – couldn't we do without it?

Einfluss der Mikroelektrodenableitung und Teststimulation auf die Position der definitiven Elektrode zur der tiefen Hirnstimulation des Nucleus subthalamicus bei Parkinsonpatienten – könnten wir nicht darauf verzichten?

Meeting Abstract

  • corresponding author J. Helm - Klinik für Neurochirurgie, Universitätsklinikum Leipzig
  • D. Winkler - Klinik für Neurochirurgie, Universitätsklinikum Leipzig
  • J. Schwarz - Klinik für Neurologie, Universitätsklinikum Leipzig
  • K. Strecker - Klinik für Neurologie, Universitätsklinikum Leipzig
  • J. Meixensberger - Klinik für Neurochirurgie, Universitätsklinikum Leipzig

Deutsche Gesellschaft für Neurochirurgie. Società Italiana di Neurochirurgia. 59. Jahrestagung der Deutschen Gesellschaft für Neurochirurgie e.V. (DGNC), 3. Joint Meeting mit der Italienischen Gesellschaft für Neurochirurgie (SINch). Würzburg, 01.-04.06.2008. Düsseldorf: German Medical Science GMS Publishing House; 2008. DocP 099

The electronic version of this article is the complete one and can be found online at:

Published: May 30, 2008

© 2008 Helm et al.
This is an Open Access article distributed under the terms of the Creative Commons Attribution License ( You are free: to Share – to copy, distribute and transmit the work, provided the original author and source are credited.



Objective: Microelectrode recording in STN-DBS for PD is a widespread measure but it consumes time and staff. The aim of this study was to challenge the “feeling of necessity” of MER for optimal electrode positioning.

Methods: In 35 consecutive PD patients bilateral DBS of STN was done following the same algorithm (April 2004 to November 2007). Patients were awake or under mild analgesia or sedation. Typical STN signals were searched in order to define the electrophysiological borders of the STN. After comparison of the 5 trajectories the most promising ones were selected for test stimulation at several levels. The site of optimal test stimulation (best effect, least side effects) was the main determiner of definite electrode position. For this study we analyzed the number and location of MER trajectories with typical STN signals, the cases in which the central trajectory was not found to be the optimal for test stimulation or definite electrode positioning and the cases were test stimulation lead to a modification of initially intended definite electrode position. A subgroup of patients operated with conventional stereotactic frame (n=19) was compared to a second group of patients were the stereotactic approach was done by means of a specific stereotactic platform (n=16).

Results: Typical STN signals were achieved in 218 of 342 trajectories (3.11 out of 5 per side). Lack of a STN signal in central trajectory was found in 18 of 70 operated sides (25%). In other 13 cases the STN signal of the central trajectory was regarded as originating just from the very edge of STN (19%). Test stimulation in multiple trajectories was done in 22 of 70 operated sides (29%). Multiple testing lead to a revision of the initially intended electrode position in 64% of these cases. Finally only 32 electrodes (46%) were positioned at the central trajectory. There was no significant difference between the two subgroups neither in number of trajectories with typical STN signals nor in multiple trajectory testing frequency or rate of definite electrodes placed in the central trajectory.

Conclusions: Due to the specific electrophysiological information microelectrode recording leads to the abandonment of the central stereotactic trajectory in 44% of cases. After additional test stimulation the definite position was in the central trajectory only in about one half of all cases. So we conclude that in our setup MER recording and test stimulation are essential for optimal positioning of definite stimulation electrodes.