Related Experiment Video
Updated: Jun 5, 2026
Handwriting Analysis Indicates Spontaneous Dyskinesias in Neuroleptic Naïve Adolescents at High Risk for Psychosis
Published on: November 21, 2013
Micrographia induced by pallidal DBS for segmental dystonia: a subtle sign of hypokinesia?
Christian Blahak1, Hans-Holger Capelle, Hansjoerg Baezner
1Department of Neurology, Universitaetsmedizin Mannheim, UMM, University of Heidelberg, Theodor-Kutzer Ufer 1-3, 68167, Mannheim, Germany. c.blahak@neuro.ma.uni-heidelberg.de
Abstract:
Recently parkinsonism has been reported as a rare side effect of globus pallidus internus (GPi) deep brain stimulation (DBS) for dystonia. In the present systematic prospective study in 11 patients with segmental dystonia not affecting distal arm function, we could demonstrate significant changes in handwriting characterized by mild micrographia following GPi-DBS. We propose that this finding reflects GPi-DBS-induced disturbances of basal ganglia function in terms of a mild hypokinetic syndrome, as a result of outflow alterations in pallido-thalamo-cortical pathways.
Insights
Globus pallidus internus deep brain stimulation (GPi-DBS) for dystonia may cause mild micrographia, a handwriting change. This suggests GPi-DBS can induce subtle hypokinetic syndrome by altering basal ganglia pathways.
Area of Science:
- Neurology
- Neurosurgery
- Movement Disorders
Background:
- Parkinsonism is a rare reported side effect of globus pallidus internus (GPi) deep brain stimulation (DBS) for dystonia.
- The exact neurological mechanisms underlying this side effect require further investigation.
Purpose of the Study:
- To systematically investigate potential changes in handwriting following GPi-DBS in patients with dystonia.
- To explore the relationship between GPi-DBS and basal ganglia function.
Main Methods:
- A systematic prospective study was conducted.
- 11 patients with segmental dystonia not affecting distal arm function underwent GPi-DBS.
- Handwriting changes were assessed post-stimulation.
Main Results:
- Significant changes in handwriting were observed in patients after GPi-DBS.
- These changes were characterized by mild micrographia (abnormally small handwriting).
- No patients developed overt parkinsonism.
Conclusions:
- GPi-DBS for dystonia can lead to mild micrographia.
- This finding suggests GPi-DBS may induce subtle disturbances in basal ganglia function, manifesting as a mild hypokinetic syndrome.
- Altered outflow in pallido-thalamo-cortical pathways is proposed as the underlying mechanism.
