Artikel
How does dystonia recur after discontinuation of chronic deep brain stimulation?
Chronische tiefe Hirnstimulation bei Dystonie: Wiederauftreten dystoner Symptome im Zeitverlauf nach Unterbrechung der Stimulation
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Autoren
Veröffentlicht: | 23. April 2004 |
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Gliederung
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Objective
Chronic deep brain stimulation (DBS) for medically refractory dystonia has been recognized as a valuable treatment option only recently. The full effect of DBS may appear only after months, but in contrast to Parkinson´s Disease it is unknown how dystonic symptoms recur after discontinuation of chronic DBS.
Methods
In this prospective study we enclosed 8 patients with segmental or generalized dystonia who underwent pallidal (7 patients) or thalamic (1 patient) chronic DBS. Mean age at surgery was 47.9 years, there were 4 men and 4 women. The time course of the appearance of dystonic symptoms has been assessed at 5±2 months postoperatively according to the Burke-Fahn-Marsden (BFM) Dystonia Scale immediately and at 4 hours after switching off DBS.
Results
Seven patients benefitted from chronic DBS, while one patient had no improvement. After discontinuation of DBS, dystonic symptoms recurred within minutes in 3 patients. In one of these patients, further worsening of dystonia was observed over the next four hours. In the other 4 patients dystonic symptoms only gradually returned to baseline at 4 hours. The dystonic symptoms which reappeared early after discontinuation of DBS were primarily phasic, while those which worsened gradually were the tonic components.
Conclusions
Discontinuation of chronic DBS in patients with dystonia has a differential impact on the time course of the reappearance of phasic and tonic dystonic movements. These findings indicate that the effect of DBS on dystonic symptoms are mediated via different pathophysiological processes.