Changes in handwriting resulting from bilateral high-frequency stimulation of the subthalamic nucleus in Parkinson's disease
✍ Scribed by Hartwig Roman Siebner; Andres Ceballos-Baumann; Harald Standhardt; Carola Auer; Bastian Conrad; Francois Alesch
- Publisher
- John Wiley and Sons
- Year
- 1999
- Tongue
- English
- Weight
- 95 KB
- Volume
- 14
- Category
- Article
- ISSN
- 0885-3185
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✦ Synopsis
High-frequency stimulation of the subthalamic nucleus (STN) is a promising therapeutic approach in patients with severely disabling Parkinson's disease (PD). Whereas STN stimulation improves the cardinal signs of PD, little is known about the effects of STN stimulation on fine manual skills like handwriting. Therefore, the present study investigated the changes in handwriting during bilateral STN stimulation in 12 patients with advanced PD. Dopaminergic medication was discontinued at least 12 hours before the study. The patients were asked to write a standardized sentence repetitively. Five samples of the patient's script were recorded during effective bilateral STN stimulation and 1 hour after both stimulators had been switched off. The movements of the tip of the pencil were recorded using a digitizing tablet. Handwriting movements were segmented into subsequent up-and downstrokes, and a stroke-based kinematic analysis of handwriting was performed. During high-frequency STN stimulation, handwriting movements became faster and smoother indicating a partial restoration of an "open-loop" automatic performance. In addition, STN stimulation gave rise to a significant increase in the mean vertical stroke length demonstrating a stimulationrelated reduction in micrographia. The present data underscores the importance of the STN in "open-loop" performance of highly skilled sequential hand movements.