Deep Brain Stimulation Target Selection For Dystonia

Objective: Surgical procedures involving deep brain stimulation(DBS)of the globus pallidus internus(GPi)or subthalamic nucleus(STN)are well-established treatments for isolated dystonia.However,selection of the best stimulation target remains a matter of debate.The authors’ objective was to compare the effectiveness of DBS of the GPi and the STN in patients with isolated dystonia.Methods: In this matched retrospective cohort study,the authors searched an institutional database for data on all patients with isolated dystonia who had undergone bilateral implantation of DBS electrodes in either the GPi or STN in the period from January 30,2014,to June 30,2017.Standardized assessments of dystonia and health-related quality of life(Qo L)using the Burke-Fahn-Marsden Dystonia Rating Scale(BFMDRS)and Medical Outcomes Study 36-item Short-Form General Health Survey(SF-36)were conducted before and at 1,6,and 12 months after surgery.No patients were lost to the 6-month follow-up;5 patients were lost to the 12-month follow-up.Results: Both GPi(14 patients)and STN(16 patients)stimulation produced significant improvement in dystonia and quality of life in all 30 patients found in the database search.At the 1-month follow-up,however,the percentage improvement in the BFMDRS total movement score was significantly(p = 0.01)larger after STN DBS(64%)than after GPi DBS(48%).At the 12-month follow-up,the percentage improvement in the axis subscore was significantly(p = 0.03)larger after GPi DBS(93%)than after STN DBS(83%).Also,the total amount of electrical energy delivered was significantly(p = 0.008)lower with STN DBS than with GPi DBS(124 ± 52 vs 192 ± 65 m J,respectively).Conclusions: The GPi and STN are both effective targets in alleviating dystonia and improving quality of life.However,GPi stimulation may be better for patients with axial symptoms.Moreover,STN stimulation may produce a larger clinical response within 1month after surgery and may have a potential economic advantage in terms of lower battery consumption.Objective: To evaluate the long-term clinical effectiveness and safety of subthalamic nucleus deep brain stimulation(STN-DBS)for medically intractable pediatric isolated dystonia.Methods: Using a longitudinal retrospective design,we assessed the clinical outcomes of nine patients who underwent STN-DBS for treatment-refractory pediatric isolated dystonia one decade ago(mean age at surgery: 15.9 ± 4.5 years).The primary clinical outcome used was assessed by retrospective video analyses of patients’ dystonia symptoms using the Burke-Fahn-Marsden Dystonia Rating Scale(BFMDRS).Clinical assessments were performed at baseline,1-year follow-up(1-yr FU),and 10-year follow-up(10-yr FU).Adverse side effects,including surgery-related,device-related,and stimulation-related effects,were also documented.Results: After STN-DBS surgery,the mean improvement in the BFMDRS motor score was 77.1 ± 26.6% at 1-yr FU and 90.4 ± 10.4% at 10-yr FU.Similarly,the mean BFMDRS disability score was improved by 69.5 ± 13.6% at 1-yr FU and by 86.5 ± 13.9% at 10-yr FU.The clinical improvements gained at 10-yr FU were signifificantly larger than those observed at 1-yr FU.Negative correlations were found between the duration of disease to age at surgery ratio(DD/AS)and the improvements in the BFMDRS motor score and total score at 1-yr FU and 10-yr FU.Conclusion: This study provides the first clinical evidence for the short-and long-term effectiveness and safety of STN-DBS for pediatric isolated dystonia.Objective: Post‐traumatic dystonia(PTD)definded as dystonia developing after brain injury,which is one type of acquired dystonia.Deep brain stimulation(DBS)has been proposed as an effective treatment for drug-intolerant isolated dystonia(one type of acquired dystonia),but whether it is also efficacious for post-traumatic dystonia(PTD)is unknown.Reports are few in number and have reached controversial conclusions regarding the choice of DBS targets for PTD treatment.Here,we report a case series of five PTD patients with improved clinical benefit following DBS treatment.Methods: Five patients with disabling PTD underwent DBS therapy.The clinical outcomes were assessed with the Burke-Fahn-Marsden dystonia rating scale(BFMDRS)at baseline and the last follow-up visit(at more than 12 months).Results: Patients 1 and 3 received unilateral globus pallidus internus(GPi)DBS for contralateral dystonia.The subthalamic nucleus(STN)was chosen as target for patients 2 and 4,due to a lesion located in the globus pallidus.Patient 5 had an electrode in the ventral intermediate nucleus(VIM)for treating predominant tremor of left upper extremity,with unexpected improvement of focal hand dystonia.The scores of BFMDRS movement exhibited favorable improvement in all five patients at the last follow-up,ranging from 52.4% to 78.6%.Conclusions: DBS may be an effective and safe treatment for medically refractory PTD,but this needs to be confirmed by further studies.Globus pallidus internus(GPi)deep brain stimulation(DBS)is widely used in patients with isolated dystonia,but its use in patients with acquired dystonia with cerebral palsy remains controversial.Cerebellar stimulation can affect pathological abnormalities of movement disorders through several connections between the cerebellum and motor cortex,as well as between the cerebellum and sub-cortical structures.We evaluated whether cerebellum DBS was effective in a patient with acquired dystonia.To this aim,we performed bilateral cerebellum DBS with electrodes over both superior cerebellar peduncles(SCPs)and dentate nuclei(DNs)in a patient of cerebral palsy with severe generalized dystonia and spasticity,who had received no benefit from GPi DBS two years prior.The monopolar stimulation test results suggested that DBS administered via the SCP may be better than that administered via the DN.Six months following chronic SCP DBS,the patient exhibited a considerable reduction in dystonia(with a 36.4% and 33.3% improvement in movement and disability,respectively)and spasticity(33.3%).Voice was significantly improved and quality of life(75%)also improved,with subjective reports of a reduction in cognitive deficits,pain,and negative emotion.To conclude,SCP DBS may be a potential treatment for patients with cerebral palsy with dystonia and spasticity who have not responded to GPi DBS.