| Background:It was Tulpius who firstly came up with the concept about dystonia in the description of the spasmodic torticollis in 1652. After a long period of exploring for the disease, Oppenheim, for the first time, preliminarily summarized the concept of dystonia in 1911.Since then, with the understanding of the disease deepening and more and more research put into it, the international dystonia medical research foundation advisory committee put forward to the definition of dystonia in 1984: dystonia is a kind of a syndrome characterized by distortion,repetitive movement and abnormal posture which are caused by involuntary persistent muscle contraction.Dystonia is a kind of the movement disorders in functional neurosurgery diseases and the morbidity of it is the second to Parkinson’s diseases’. In recent years with the help of the molecular biology and imaging disciplines, we have had a deeper understanding of the disease than before. However the exact etiology and pathogenesis of the dystonia is still unclear and the treatment of it still remains at the symptomatic treatment level. At present, there are quite a number of patients eventually have to get a hand from surgical treatment in that the efficacy of the medicine decline because of long-term treatment or the patients cannot tolerate the side effects of it, clinically. The surgical treatment of the dystonia developed from peripheral nerve or muscle amputation, thalamotomy, pallidotomy, radiofrequency derogation under stereotactic orientation to multiple target in the brain to the deep brain stimulation(DBS) under stereotactic orientation.Stereotactic deep brain stimulation is a safe and effective treatment for the dystonia, meanwhile it also has the reversible, adjustable and controllable characteristics. At present, there are mainly two targets chose to treat the dystonia clinically in domestic and overseas: subthalamic nucleus(STN) and the globus pallidus internus(GPi). But there is still no final conclusion for the questions whether the curative effect of the two targets is different and whether the postoperative parameter of programming between the two target is different and the problem of how to master the operation indications of preoperative. Objective:In order to explore the problems above further, we performed this clinical experiment through which we successively retrospectively recalled 29 cases of patients with primary and secondary dystonia and 21 patients with primary dystonia among the 29, and all of them accepted the deep brain stimulation surgery wit h STN-DBS or GPi-DBS. And we compared the differences of the scores of each patient between preoperative and postoperative based on the Burke-Fahn-Marsden dystonia rating scales(BFMDRS) and the distinction of the postoperative parameters of programing between the STN subgroup and the GPi subgroup in the primary dystonia group, discussing the pathogenesis of the dystonia and the mechanism of DBS in the treatment of dystonia. In the end we attempted to provide the theoretical basis which could help the clinician understand the disease further, and it could let them know how to master the surgical indications preoperatively and what influences on the disease prognosis DBS surgery can bring for the patients. Methods:We, retrospectively, collected 34 cases of patients with dystonia who accepted the surgical treatment of STN-DBS or GPi-DBS in our department from December 2004 to June 2013. In the first part of our clinical trial, we respectively scored the movement subscale and the disability subscale of the 29 cases of patients with primary or second dystonia in the treatment of STN-DBS or GPi-DBS according to the BFMDRS, statistically analyzing the differences of the scores to evaluate the distinct of the efficacy of the patients with the two targets and finally summarize the indications of the surgery and guide clinical practice for the clinician. In the second part, we statistically analyzed the parameters of programming in different postoperative period of the STN-DBS sub-group and the GPi-DBS sub-group in 21 patients with primary dystonia in order to observe whether there are some differences between the STN-DBS sub-group and the GPi-DBS sub-group in postoperative parameters of programming. Results:34 patients have successfully undergone the DBS surgery. Postoperative cranial MRI re-examination showed the location of intracranial electrodes was accurate. Temporary external electric stimulation was used to observe the therapeutic effect after the one-stage operation, and the symptoms for most of the patients were ameliorated. However, 4 patients did not get any benefits, and infection occurred for 1 patient after the implantation of IPG, thus the whole stimulus apparatus were removed from these 5 patients finally. The other 29 patients all completed the follow up after the turning on of the stimulation.The first part of the present study was to observe the pre- and post- operative conditions of the 29 patients suffering from the dystonia. These 29 patients were divided into 4 groups by etiology and stimulus targets: primary-STN group, primary-GPi group, secondary-STN group and secondary-GPi group. The scores by BFMDRS at different time points for above mentioned group indicated that stimulus targeting GPi and STN can both ameliorate the primary dystonia patients, and both motor and disability scores gradually decreased with the extension of the stimulus time. By statistically analysis, there was significant difference between pre- and post- operative BFM scores for both primary-STN and primary-GPi group(P<0.05);However, though postoperative BFM scores showed decrease trends for both secondary-STN and secondary-GPi group, there was no significant difference comparing to the pre-operation status, that is, there was no significant difference between pre- and post- operative BFM scores(P>0.05).The comparison of post-operative motor scores(at the same time)between the mentioned four groups showed that the difference of average improvement rate between the primary-STN and primary-GPi group have statistical significance at 1, 3, and 6 month after surgery(p<0.05); There was no significant difference for average improvement rate between the two groups at 12 and 24 months postoperatively. The same as to the disability scores, there was significant difference for average improvement rate between the two groups at 1 month postoperatively,but not at the 3, 6, 12 and 24 months after surgery(p>0.05). For the secondary STN and secondary GPi groups, the improvement for neither postoperative motor nor disability scores is of significant difference(p>0.05).For the patients who suffering from the disease longer than 20 years, and those have secondary dystonia, the DBS surgery did not show good effect. The patients who have disease onset age later than 40 years and the deterioration of their disease is faster did not get good therapeutic effect.The second part of the study observing the programing parameters postoperatively for the 21 primary dystonia patients showed that the parameters for the STN group is :amplitude is 1.3-3.2v, pulse width is 60-120μs, the frequency is 60-185 Hz. The parameters for the GPi group is:amplitude is 2.0-3.8v,pulse width is 60-150μs, the frequency is 30-150 Hz. There is no significant difference for the programing parameters at 3, 6, and 24 month for both primary STN and GPi groups. Conclusion:Stereotactic deep brain stimulation is effective and safe method treating dystonia, and has the advantages of being reversible, regulatory and controlled. STN-DBS and GPi-DBS have better therapeutic effect for primary dystonia patients than secondary dystonia patients. In the long term, the effect of STN-DBS and GPi-DBS treating dystonia is similar, but the effect of STN-DBS appeared earlier than GPi-DBS.The subthalamic nuclus(STN) and globus pallidus inernus(GPi) are the two primary targets for treating dystonia by functional neurosurgery. There is no significant difference for postoperative programing parameters on amplitude, pulse width and frequency between STN-DBS and GPi-DBS, while the GPi-DBS seems to need higher amplitude than STN-DBS. |
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