gms | German Medical Science

62nd Annual Meeting of the German Society of Neurosurgery (DGNC)
Joint Meeting with the Polish Society of Neurosurgeons (PNCH)

German Society of Neurosurgery (DGNC)

7 - 11 May 2011, Hamburg

Microlesion effect (MLE) in the basal ganglia due to deep brain stimulation (DBS) on ballistic movements in Parkinson's and dystonia patients

Meeting Abstract

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  • A. Singh - 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. Polnische Gesellschaft für Neurochirurgen. 62. Jahrestagung der Deutschen Gesellschaft für Neurochirurgie (DGNC), Joint Meeting mit der Polnischen Gesellschaft für Neurochirurgen (PNCH). Hamburg, 07.-11.05.2011. Düsseldorf: German Medical Science GMS Publishing House; 2011. DocP 095

doi: 10.3205/11dgnc316, urn:nbn:de:0183-11dgnc3161

Published: April 28, 2011

© 2011 Singh 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: Bradykinesia and hypokinesia are the prominent symptoms of substantia nigra (SN) degeneration in Parkinson's disease (PD), whereas in segmental dystonia, which is characterized by involuntary muscle contractions, normally no bradykinetic or hypokinetic features are seen and the movements of non-affected limbs are not impaired. Both conditions can be treated effectively with deep brain stimulation (DBS). In the current study we analyzed the impact of the microlesion-effect (MLE) caused by the mere implantation of DBS-electrodes on the performance of fast movements in these two groups.

Methods: We investigated 9 PD patients with subthalamic electrodes and 9 patients with cervical dystonia with electrodes in the globus pallidus internus (GPi). Patients were studied on the first postoperative day without electrical stimulation of the electrodes after standard electrode implantation (DBS 3387 (dystonia) or 3389 (PD) Medtronic) had been performed with MRI-guided stereotaxy. Subjects had to perform 30 self-paced fast boxing movements with their right and left arm sequentially under two conditions: a) the movement ended by hitting the target (a punching bag) (boxing with touch: BWT) and b) the fist had to be stopped in front of the target (boxing no touch: BNT). A calibrated goniometer was used to record elbow joint position and to compute angular joint movement velocity.

Results: All PD patients as well as 4/9 patients with dystonia showed an instantaneous provisional improvement of motor symptoms subsequent to surgery. Results from post-hoc Scheffé comparisons indicated that PD subjects acted faster during BWT movements than during BNT movements (p < 0.001). PD subjects also performed the BWT task with a higher velocity than the dystonic group (p = 0.03). In the group of dystonia patients, there was no significant difference in the velocity of the two tasks (p = 0.85). There was no significant difference in the amplitudes between the groups (f (1.53) = 2.09, p =0.154) and (f (1,53) = 2.88, p = 0.096).

Conclusions: Our findings suggest that a small subthalamic lesion in individuals with PD specifically reverses bradykinesia during simple ballistic movements (touch) but not during complex ones requiring more pre-programming (no-touch paradigm). There was no evidence for a similar MLE after GPi implantation in dystonia patients.