Mark K. Lyons 
	
                                                                                                            Mayo Clinic Arizona, 
5777 East Mayo Boulevard, Mayo Clinic Hospital 5 East Phoenix, AZ 85054
Tanzania                                    	
                                    
 Research Article
                                                                        Spasmodic Dysphonia and Thalamic Deep Brain Stimulation: Long-term Observations, Possible Neurophysiologic Mechanism and Comparison of Unilateral Versus Bilateral Stimulation                                     
Author(s): Mark K. Lyons, Orland K. Boucher and Virgilio G. H. EvidenteMark K. Lyons, Orland K. Boucher and Virgilio G. H. Evidente             
                                    
                                                                        
                             The  co-existence  of  essential  tremor  and  spasmodic  dysphonia  has  been  reported  in  the  literature.  Spasmodic  dysphonia is a primary focal dystonia manifested by loss of control of the vocal muscles during speech secondary to  laryngeal muscle spasms. The pathophysiology is not well understood. Deep brain stimulation surgery (DBS) for other  focal dystonias has been well reported. Voice and laryngo-videostroboscopic examinations can aid in confirmation  of  spasmodic  dysphonia  as  opposed  to  voice  tremor  due  to  the  underlying  essential  tremor.  We  report  the  long  term  follow  up  of  a  patient  who  underwent  bilateral  thalamic  deep  brain  stimulation  surgery  for  essential  tremor  and  coincident spasmodic dysphonia, and report the effects of unilateral versus bilateral stimulation on her dysphonia. The  topic literature is reviewed and the potent.. View More»