Use of surface electromyography to assess and select patients with idiopathic dystonia for bilateral pallidal stimulation.

OBJECT The object of this study was to identify a preoperative physiological index by using surface electromyography (EMG) signals that would correlate with clinical outcome in dystonic patients following bilateral pallidal stimulation. METHODS In 14 patients with spasmodic torticollis, generalized dystonia, and myoclonic dystonia, surface EMG signals were recorded from the most affected muscle groups. Although the dystonia affected different body segments, the EMG signals in all patients could be decomposed into bursting and sustained components. Subsequently, a ratio of the EMG amplitude was calculated between the two components and then correlated with clinical outcome. Patients who experienced rapid improvement following bilateral pallidal stimulation had a significantly higher EMG ratio compared with those who did not. Furthermore, a significant correlation was found between the EMG ratio and clinical improvement during the 12-month period following pallidal stimulation. CONCLUSIONS The authors concluded that surface EMG studies could be used to predict the clinical outcome of and to select patients for pallidal stimulation for dystonia.

[1]  Tipu Z. Aziz,et al.  Extracting burst and tonic components from surface electromyograms in dystonia using adaptive wavelet shrinkage , 2004, Journal of Neuroscience Methods.

[2]  S. Hemm,et al.  Electrical stimulation of the globus pallidus internus in patients with primary generalized dystonia: long-term results. , 2004, Journal of neurosurgery.

[3]  P. Greene,et al.  Deep-brain stimulation for generalized dystonia. , 2005, The New England journal of medicine.

[4]  A. Destée,et al.  Bilateral deep-brain stimulation of the globus pallidus in primary generalized dystonia. , 2005, The New England journal of medicine.

[5]  J. Volkmann,et al.  Deep brain stimulation for dystonia: Patient selection and evaluation , 2002, Movement disorders : official journal of the Movement Disorder Society.

[6]  R. Kumar,et al.  Methods for programming and patient management with deep brain stimulation of the globus pallidus for the treatment of advanced Parkinson's disease and dystonia , 2002, Movement disorders : official journal of the Movement Disorder Society.

[7]  J. Volkmann,et al.  Pallidal Stimulation for Dystonia , 2004, Neurosurgery.

[8]  A. Lang,et al.  Teaching tape for the motor section of the toronto western spasmodic torticollis scale , 1997, Movement disorders : official journal of the Movement Disorder Society.

[9]  M. Heilbrun,et al.  Optimal target localization for ventroposterolateral pallidotomy: the role of imaging, impedance measurement, macrostimulation and microelectrode recording. , 1997, Stereotactic and functional neurosurgery.

[10]  M. Asmussen.  The use of incompletely linked markers in genetic counseling: accuracy versus linkage. , 1985, Human heredity.

[11]  E. Taub,et al.  Pallidal deep brain stimulation in patients with cervical dystonia and severe cervical dyskinesias with cervical myelopathy , 2002, Journal of neurology, neurosurgery, and psychiatry.

[12]  John Yianni,et al.  Deep Brain Stimulation for Dystonia , 2004, Journal of clinical neurophysiology : official publication of the American Electroencephalographic Society.

[13]  J F Stein,et al.  Post‐operative progress of dystonia patients following globus pallidus internus deep brain stimulation , 2003, European journal of neurology.

[14]  Hyeonki Choi,et al.  Quantitative assessment of co-contraction in cervical musculature. , 2003, Medical engineering & physics.

[15]  S Benjamin,et al.  How to examine patients using the Abnormal Involuntary Movement Scale. , 1988, Hospital & community psychiatry.

[16]  J. Vitek.  Pathophysiology of dystonia: A neuronal model , 2002, Movement disorders : official journal of the Movement Disorder Society.

[17]  Laurent Vercueil,et al.  Results of deep brain stimulation for dystonia: A critical reappraisal , 2002, Movement disorders : official journal of the Movement Disorder Society.

[18]  J. Dostrovsky,et al.  Pallidal neuronal activity: Implications for models of dystonia , 2003, Annals of neurology.

[19]  Joachim K. Krauss,et al.  Deep Brain Stimulation for Dystonia in Adults , 2003, Stereotactic and Functional Neurosurgery.

[20]  Reversal of hypertonic co‐contraction after bilateral pallidal stimulation in generalised dystonia: A clinical and electromyogram case study , 2004, Movement disorders : official journal of the Movement Disorder Society.

[21]  T. Aziz,et al.  Use of the Radionics Image Fusion™ and Stereoplan™ programs for target localization in functional neurosurgery , 1998, Journal of Clinical Neuroscience.

[22]  R. Miall,et al.  Involvement of the medial pallidum in focal myoclonic dystonia: A clinical and neurophysiological case study , 2002, Movement disorders : official journal of the Movement Disorder Society.

[23]  C. Marsden,et al.  Validity and reliability of a rating scale for the primary torsion dystonias , 1985, Neurology.

[24]  M. Hallett,et al.  The pathophysiology of primary dystonia. , 1998, Brain : a journal of neurology.