Deep Brain Stimulation Management of Essential Tremor with Dystonic Features

Clinical Vignette: A 64-year-old female with essential tremor (ET) presents for evaluation of deep brain stimulation (DBS) candidacy. Examination revealed subtle dystonic features as well as a disabling postural-action tremor. Clinical Dilemma: Can dystonia occur in the setting of the diagnosis of ET and can its presence alter DBS target selection? Clinical Solution: Unilateral DBS implantation of the ventralis intermedius (Vim) led to improvement in both tremor and dystonic posturing. Gap in Knowledge: Case reports of DBS in dystonic tremor suggest Vim, globus pallidus internus (GPi), and subthalamic targets may all be effective, to varying degrees, in improving both tremor and dystonia. More rigorous studies are needed to identify the optimal target(s). Expert Commentary: This case underscores the limited evidence available to guide a clinician’s choice of DBS targets in patients with ET and dystonia. The severity of the dystonia and the presence of more generalized dystonia may alter the thinking about optimal targeting. Vim, GPi, and subthalamic targets appear potentially acceptable options, though Vim is usually the first target attempted when postural-action tremor is the chief complaint. Occasionally, a second rescue DBS lead may be necessary

Dorsal GPi/GPe Stimulation Induced Dyskinesia in a Patient with Parkinson’s Disease

Clinical vignette: A 68-year-old man with Parkinson’s disease (PD) had bilateral GPi DBS placed for management of his motor fluctuations. He developed stimulation-induced dyskinesia (SID) with left dorsal GPi stimulation. Clinical dilemma: What do we know about SID in PD patients with GPi DBS? What are the potential strategies used to maximize the DBS therapeutic benefit and minimize the side effects of stimulation? Clinical solution: Avoiding the contact implicated in SID and programming more ventral contacts, using lower voltage, frequency and pulse width and programming in bipolar configuration all appear to help minimize the SID and provide appropriate symptomatic motor control. Gap in knowledge: Little is known about SID in patients with PD who had GPi DBS therapy. More studies using volume of tissue activated and diffusion tensor imaging MRI are needed to localize specific tracts in or around the GPi that may be implicated in SID

Deep brain stimulation for Tourette’s syndrome

Abstract: Tourette syndrome (TS) is a childhood-onset neuropsychiatric disorder characterized by the presence of multiple motor and vocal tics. TS usually co-occurs with one or multiple psychiatric disorders. Although behavioral and pharmacological treatments for TS are available, some patients do not respond to the available treatments. For these patients, TS is a severe, chronic, and disabling disorder. In recent years, deep brain stimulation (DBS) of basal ganglia-thalamocortical networks has emerged as a promising intervention for refractory TS with or without psychiatric comorbidities. Three major challenges need to be addressed to move the field of DBS treatment for TS forward: (1) patient and DBS target selection, (2) ethical concerns with treating pediatric patients, and (3) DBS treatment optimization and improvement of individual patient outcomes (motor and phonic tics, as well as functioning and quality of life). The Tourette Association of America and the American Academy of Neurology have recently released their recommendations regarding surgical treatment for refractory TS. Here, we describe the challenges, advancements, and promises of the use of DBS in the treatment of TS. We summarize the results of clinical studies and discuss the ethical issues involved in treating pediatric patients. Our aim is to provide a better understanding of the feasibility, safety, selection process, and clinical effectiveness of DBS treatment for select cases of severe and medically intractable TS

Deep brain stimulation for Tourette’s syndrome

Abstract: Tourette syndrome (TS) is a childhood-onset neuropsychiatric disorder characterized by the presence of multiple motor and vocal tics. TS usually co-occurs with one or multiple psychiatric disorders. Although behavioral and pharmacological treatments for TS are available, some patients do not respond to the available treatments. For these patients, TS is a severe, chronic, and disabling disorder. In recent years, deep brain stimulation (DBS) of basal ganglia-thalamocortical networks has emerged as a promising intervention for refractory TS with or without psychiatric comorbidities. Three major challenges need to be addressed to move the field of DBS treatment for TS forward: (1) patient and DBS target selection, (2) ethical concerns with treating pediatric patients, and (3) DBS treatment optimization and improvement of individual patient outcomes (motor and phonic tics, as well as functioning and quality of life). The Tourette Association of America and the American Academy of Neurology have recently released their recommendations regarding surgical treatment for refractory TS. Here, we describe the challenges, advancements, and promises of the use of DBS in the treatment of TS. We summarize the results of clinical studies and discuss the ethical issues involved in treating pediatric patients. Our aim is to provide a better understanding of the feasibility, safety, selection process, and clinical effectiveness of DBS treatment for select cases of severe and medically intractable TS

Evolution of Globus Pallidus Targeting for Parkinson\u27s and Dystonia Deep Brain Stimulation: A 15-Year Experience

Objective: The aim of this study is to evaluate the evolution of GPi DBS targeting. Methods: This retrospective, single-center study included patients implanted with GPi DBS leads for dystonia or PD during the years 2004 to 2018 at the University of Florida Fixel Institute for Neurological Diseases. Each patient underwent a high-resolution targeting study on the day prior to the surgery, which was fused with a high resolution CT scan that was acquired on the day of the procedure. Intraoperative target location was selected using a digitized 3D Schaltenbrand-Bailey atlas. All patients underwent a high-resolution head CT scan without contrast approximately one month after lead implantation and accurate measurement of neuroanatomical lead position was acquired after fusion of pre-operative and post-operative image studies. Results: We analyzed 253 PD patients with 352 leads and 80 dystonia patients with 141 leads. During 15 years of follow-up, lead locations in the PD group migrated more laterally (beta = 0.09, p \u3c 0.0001), posteriorly [slope (beta) = 0.04, p \u3c 0.05], and dorsally (beta = 0.07, p \u3c 0.001), whereas leads in the dystonia group did not significantly change position aside from a trend in the dorsal direction (beta = 0.06, p = 0.053). Conclusion: The evolving target likely results from multiple factors including improvements in targeting techniques and clinical feedback intraoperatively and post-operatively. Our demonstrates the potential importance of a systematic post-operative DBS lead measurement protocol to ensure quality control and to inform and optimize DBS programming

Clinical Practice Patterns in Tic Disorders Among Movement Disorder Society Members

[Background] Tic disorders belong to the broad spectrum of pediatric and adult movement disorders. The wide variability in clinical presentations, applied assessment tools, and treatments are poorly understood.[Objectives] To map practices and knowledge base of movement disorder clinicians concerning clinical features, pathophysiology, and treatment approaches in tic disorders. [Methods] A 33-item survey was developed by the Tic Disorders and Tourette syndrome Study Group members of the Movement Disorder Society. The survey was distributed to the complete society membership and included responses from 346 members, 314 of whom reported treating tic disorders. [Results] Approximately one third of survey respondents (35%) frequently evaluated patients with tics. The data revealed widespread use of existing guidelines (about 70%) and screening for comorbid disorders (>90%). The most common investigations used to rule out secondary causes of tics were imaging (92%), laboratory tests (66%) and neurophysiology (38%). Functional tics were the second most common tic etiology following primary tics. Only 27% of respondents reported confidence in knowledge about tic pathogenesis. Top rated interventions to treat tics were psychoeducation, cognitive behavioral intervention for tics (CBIT) and treatment for neuropsychiatric comorbidities. Antipsychotics were ranked as the most effective pharmacologic tic intervention. Conclusions: The majority of movement disorders specialists do not frequently encounter tics. There was sparse knowledge about tic pathophysiology. Psychoeducation, CBIT, the treatment of neuropsychiatric comorbidities and use of antipsychotics emerged as the most common interventions to treat tics. These results provide insight into what will be needed to improve the diagnosis and treatment of tic disorders.CG is supported by the Freigeist Fellowship of the VolkswagenStiftung. He has served as ad hoc advisory board to Biomarin and received honoraria from the International Parkinsons Disease and Movement Disorders Society for educational activities

Functional Movement Disorders and Deep Brain Stimulation: A Multi-Center Study

[Background] Functional movement disorders (FMD) are a commonly under-recognized diagnosis in patients with underlying neurodegenerative diseases. FMD have been observed in patients undergoing deep brain stimulation (DBS) for Parkinson's disease (PD) and other movement disorders. The prevalence of coexisting FMD among movement disorder-related DBS patients is unknown, and it may occur more often than previously recognized.[Methods] We retrospectively assessed the relative prevalence and clinical characteristics of FMD occurring post-DBS, in PD and dystonia patients (FMD+, n = 29). We compared this cohort with age at surgery-, sex-, and diagnosis-matched subjects without FMD post-DBS (FMD−, n = 29).[Results] Both the FMD prevalence (0.2%–2.1%) and the number of cases/DBS procedures/year varied across centers (0.15–3.65). A total of nine of 29 FMD+ cases reported worse outcomes following DBS. Although FMD+ and FMD− manifested similar features, FMD+ showed higher psychiatric comorbidity.[Conclusions] DBS may be complicated by the development of FMD in a subset of patients, particularly those with pre-morbid psychiatric conditions.Peer reviewe

Proceedings of the Fourth Annual Deep Brain Stimulation Think Tank: A Review of Emerging Issues and Technologies

This paper provides an overview of current progress in the technological advances and the use of deep brain stimulation (DBS) to treat neurological and neuropsychiatric disorders, as presented by participants of the Fourth Annual DBS Think Tank, which was convened in March 2016 in conjunction with the Center for Movement Disorders and Neurorestoration at the University of Florida, Gainesveille FL, USA. The Think Tank discussions first focused on policy and advocacy in DBS research and clinical practice, formation of registries, and issues involving the use of DBS in the treatment of Tourette Syndrome. Next, advances in the use of neuroimaging and electrochemical markers to enhance DBS specificity were addressed. Updates on ongoing use and developments of DBS for the treatment of Parkinson’s disease, essential tremor, Alzheimer’s disease, depression, post-traumatic stress disorder, obesity, addiction were presented, and progress toward innovation(s) in closed-loop applications were discussed. Each section of these proceedings provides updates and highlights of new information as presented at this year’s international Think Tank, with a view toward current and near future advancement of the field