Changes in blink reflex excitability after globus pallidus internus stimulation for dystonia
Article first published online: 22 JUN 2006
Copyright © 2006 Movement Disorder Society
Volume 21, Issue 10, pages 1650–1655, October 2006
How to Cite
Tisch, S., Limousin, P., Rothwell, J. C., Asselman, P., Quinn, N., Jahanshahi, M., Bhatia, K. P. and Hariz, M. (2006), Changes in blink reflex excitability after globus pallidus internus stimulation for dystonia. Mov. Disord., 21: 1650–1655. doi: 10.1002/mds.20899
- Issue published online: 20 OCT 2006
- Article first published online: 22 JUN 2006
- Manuscript Accepted: 26 NOV 2005
- Manuscript Revised: 21 NOV 2005
- Manuscript Received: 26 SEP 2005
- Brain Research Trust U.K.
- Parkinson's Appeal U.K.
- Medical Research Council U.K.
- National Institute of Neurological Disorders and Stroke, National Institutes of Health
- blink vellex;
- deep brain stimulation
A pathophysiological feature of dystonia is reduced inhibition at various levels of the nervous system, which may be detected in clinically unaffected body parts. Chronic deep brain stimulation (DBS) of the globus pallidus internus (GPi) has emerged as an effective treatment for primary torsion dystonia (PTD), although its mechanism of action and impact on inhibitory abnormalities in dystonia are unknown. We sought to understand the effect of GPi DBS on brainstem excitability in patients with PTD. We measured the blink reflex from orbicularis oculi in response to paired electrical stimulation of the supraorbital nerve at interstimulus intervals of 500 and 1,000 milliseconds in 10 patients with PTD before and at intervals of 1, 3, and 6 months after bilateral GPi DBS and in 10 healthy subjects. Patients were clinically evaluated using the Burke–Fahn–Marsden dystonia rating scale. We found R2 inhibition was significantly decreased in PTD patients compared with control subjects and progressively increased after GPi DBS, which correlated with clinical improvement in dystonia. We conclude that GPi DBS for PTD results in functional reorganization of the nervous system, which includes a long-term increase in brainstem inhibition. © 2006 Movement Disorder Society