gms | German Medical Science

63. Jahrestagung der Deutschen Gesellschaft für Neurochirurgie (DGNC)
Joint Meeting mit der Japanischen Gesellschaft für Neurochirurgie (JNS)

Deutsche Gesellschaft für Neurochirurgie (DGNC) e. V.

13. - 16. Juni 2012, Leipzig

Role of the microlesion effect (MLE) after DBS on simple and ballistic tasks in Parkinson's disease and Dystonia

Meeting Abstract

  • A. Singh - Neurologische Universitätsklinik, Ludwig-Maximilians-Universität München
  • S. Kammermeier - Neurologische Universitätsklinik, Ludwig-Maximilians-Universität München
  • K. Boetzel - Neurologische Universitätsklinik, Ludwig-Maximilians-Universität München
  • J.H. Mehrkens - Neurochirurgische Universitätsklinik, Ludwig-Maximilians-Universität München

Deutsche Gesellschaft für Neurochirurgie. Japanische Gesellschaft für Neurochirurgie. 63. Jahrestagung der Deutschen Gesellschaft für Neurochirurgie (DGNC), Joint Meeting mit der Japanischen Gesellschaft für Neurochirurgie (JNS). Leipzig, 13.-16.06.2012. Düsseldorf: German Medical Science GMS Publishing House; 2012. DocDO.04.03

DOI: 10.3205/12dgnc048, URN: urn:nbn:de:0183-12dgnc0488

Veröffentlicht: 4. Juni 2012

© 2012 Singh et al.
Dieser Artikel ist ein Open Access-Artikel und steht unter den Creative Commons Lizenzbedingungen (http://creativecommons.org/licenses/by-nc-nd/3.0/deed.de). Er darf vervielfältigt, verbreitet und öffentlich zugänglich gemacht werden, vorausgesetzt dass Autor und Quelle genannt werden.


Gliederung

Text

Objective: Many patients undergoing DBS show an improvement of symptoms right after lead-implantation even before stimulation due to a so-called microlesion effect (MLE), the precise mechanism of which remains unknown. It is assumed that the MLE is caused by inactivation of neurons surrounding the electrode by local edema. Previous studies on the MLE in PD as well as in dystonia used motor scales taken by expert neurologists to assess clinical improvements. In the present study, the focus is not on MLE-induced clinical improvement but on a kinematic parameter (velocity) of limb movements and how they may be affected by the MLE.

Methods: We investigated 9 PD patients with subthalamic (STN) electrodes and 7 patients with cervical dystonia with electrodes in the globus pallidus internus (GPi). Patients were studied pre-operatively and on the first postoperative day without electrical stimulation. Repetitive finger tapping (FT) and repetitive alternating forearm pronation and supination movements (PSM) tasks were each recorded for 25 seconds. In ballistic movement tasks, patients executed repetitive fast ballistic movement with hitting the target (punching bag) with the fist, in another paradigm subjects stopped just before the target. A calibrated goniometer was used to record elbow joint position and to compute angular joint movement velocity. Both tasks were performed for 40–45 sec. Peak angular velocity of the movements was used as the criterion for evaluation. Kinematic data were pooled for both arms of an individual.

Results: PD patients executed all motor tasks with higher speed after the surgical intervention with PSM and BT movements being carried out significantly faster whereas dystonic patients performed motor tasks with significantly reduced velocity. Moreover, PD patients improved significantly in motor UPDRS score and H & Y scale (during the off-medication and off-stimulation state) compared to before surgery (motor UPDRS: p < 0.001, H & Y scale: p < 0.001), as did dystonia patients in both TWSTRS and GDS (TWSTRS: p < 0.004, GDS: p < 0.001).

Conclusions: Microlesions of the STN can accelerate movement in PD and lesions of the GPi can inhibit excessive movements in dystonia. Since these two movement disorders are at opposite ends of the spectrum, these opposite effects are therapeutic. However, it should be noted that not only excessive, but also normal movement is affected by microlesions and, in the case of dystonia, probably also by stimulation.