Gait and balance in cervical dystonia and dystonic head tremor

Background: Previous studies have found gait and balance abnormalities in patients with cervical dystonia. However, the characteristics of gait and balance in cervical dystonia with head tremors have not been ascertained. A midline constant head tremor when walking would likely render gait and balance more difficult. The pathophysiology of dystonia has also been increasingly linked with cerebellar function abnormality, commonly implicated in gait and balance disorders.Methods: We examined the gait and balance characteristics of cervical dystonia presenting with head tremors. We used the timed up-and-go (TUG) walk test, 10 m walk test, Berg Balance Scale (BBS), and Gait and Freezing questionnaire. We then assessed the gait on an instrumented walkway system to capture spatiotemporal measures such as speed, cadence, step time, step length, stride width, swing%, stance%, single support%, double support%, and gait variability index (GVI). We also assessed whether the gait in dystonic tremor (DT) differed from essential tremor (ET) and orthostatic tremor (OT), as these tremor disorders share the cerebello-thalamo-cortical pathway as the common pathological pathway.Results: 50 participants comprising DT (20 patients), ET (15 patients), and OT (15 patients) were enrolled. While the gait abnormalities were subclinical, 11/20 DT patients (55%) walked at a slower speed on the TUG, 11/20 (55%) had reduced scores on the BBS, 9/20 (45%) had increased step time, 4/20 (20%) had reduced step length, 4/20 (20%) had wider stride width, 9/20 (45%) spent greater time during double support and 8/20 (40%) patients had an abnormal GVI. Comparisons of DT with healthy control data revealed a slower gait velocity (p = 0.001) and a reduced step length (p = 0.001). Compared to DT, the ET group revealed a reduced cadence (p = 0.04) and the OT group revealed an increased TUG time (p = 0.03), reduced BBS scores (p = 0.02), reduced step length (p = 0.02), reduced cadence (p = 0.03), reduced GVI (p = 0.01), and increased double support phase (p = 0.045).Conclusion: DT is accompanied by multiple abnormalities affecting gait and balance, albeit subclinical and less pronounced than ET and OT, possibly related to more effective compensatory mechanisms. Nevertheless, these abnormalities indicate that rehabilitative measures warrant consideration when managing in clinical settings

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

Non-motor symptoms in Dystonia: From diagnosis to treatment

The Dystonia Medical Research Foundation organized an expert virtual workshop in March 2023 to review the evidence on non-motor symptoms across the spectrum of dystonia, discuss existing assessment methods, need for their harmonisation and roadmap to achieve this, and evaluate potential treatment approaches. Albeit the most investigated non-motor domains, experts highlighted the need to identify the most accurate screening procedure for depression and anxiety, clarify their mechanistic origin and quantify their response to already available therapies. Future exploration of sleep disruption in dystonia should include determining the accuracy and feasibility of wearable devices, understanding the contribution of psychotropic medication to its occurrence, and defining the interaction between maladaptive plasticity and abnormal sleep patterns. Despite recent advances in the assessment of pain in dystonia, more research is needed to elucidate the relative importance of different mechanisms called into play to explain this impactful sensory feature and the most appropriate treatments. Amongst the different non-motor features investigated in dystonia, cognitive dysfunction and fatigue require an in-depth observation to evaluate their functional impact, their clinical profile and assessment methods and, in the case of cognition, whether impairment represents a prodrome of dementia. Finally, experts identified the development and field validation of a self-rated screening tool encompassing the full spectrum of non-motor symptoms as the most urgent step towards incorporating the management of these features into routine clinical practice

An International Survey of Deep Brain Stimulation Utilization in Asia and Oceania: The DBS Think Tank East.

Introduction: To evaluate the current utilization and challenges in fully implementing the use of deep brain stimulation (DBS) treatment in Asia and Oceania. Methods: We conducted a medical literature search to identify DBS research performed by investigators with a primary affiliation in Asian and Oceania countries between March 1, 2013, and March 1, 2019, followed by an international survey-based study. Additionally, we obtained added information regarding the DBS challenges and opportunities from the technology/industry perspective within China and Japan. We also described the current situation of DBS in India. Results: Most publications (390/494; 78.95%) in the English language originated from East Asia. In West Asia, Turkey, Israel, and Iran accounted for most DBS publications. We found no publications from the remaining 35 Asian countries. Lack of community referrals to tertiary centers was identified as the most common limitation for the widespread use of DBS in Asia (68.97%). In China, despite an increasing number of centers performing DBS surgeries, most of them accomplished less than 10 cases per year. In contrast, the number of DBS cases in Japan has been decreasing. Centers offering DBS surgeries as well as corresponding fellowship training in India are limited. Conclusion: Appropriate referrals, access, infrastructure, and the presence of full multidisciplinary DBS teams are common limitations of DBS in Asia. Most centers in China, Japan, and India performed less than 10 cases per year and a future study is expected to address the impact on quality in centers performing such few cases

Proceedings of the Eighth Annual Deep Brain Stimulation Think Tank: Advances in Optogenetics, Ethical Issues Affecting DBS Research, Neuromodulatory Approaches for Depression, Adaptive Neurostimulation, and Emerging DBS Technologies

We estimate that 208,000 deep brain stimulation (DBS) devices have been implanted to address neurological and neuropsychiatric disorders worldwide. DBS Think Tank presenters pooled data and determined that DBS expanded in its scope and has been applied to multiple brain disorders in an effort to modulate neural circuitry. The DBS Think Tank was founded in 2012 providing a space where clinicians, engineers, researchers from industry and academia discuss current and emerging DBS technologies and logistical and ethical issues facing the field. The emphasis is on cutting edge research and collaboration aimed to advance the DBS field. The Eighth Annual DBS Think Tank was held virtually on September 1 and 2, 2020 (Zoom Video Communications) due to restrictions related to the COVID-19 pandemic. The meeting focused on advances in: (1) optogenetics as a tool for comprehending neurobiology of diseases and on optogenetically-inspired DBS, (2) cutting edge of emerging DBS technologies, (3) ethical issues affecting DBS research and access to care, (4) neuromodulatory approaches for depression, (5) advancing novel hardware, software and imaging methodologies, (6) use of neurophysiological signals in adaptive neurostimulation, and (7) use of more advanced technologies to improve DBS clinical outcomes. There were 178 attendees who participated in a DBS Think Tank survey, which revealed the expansion of DBS into several indications such as obesity, post-traumatic stress disorder, addiction and Alzheimer’s disease. This proceedings summarizes the advances discussed at the Eighth Annual DBS Think Tank

Cognitive Impact of Deep Brain Stimulation on Parkinson’s Disease Patients

Subthalamic nucleus (STN) or globus pallidus interna (GPi) deep brain stimulation (DBS) is considered a robust therapeutic tool in the treatment of Parkinson’s disease (PD) patients, although it has been reported to potentially cause cognitive decline in some cases. We here provide an in-depth and critical review of the current literature regarding cognition after DBS in PD, summarizing the available data on the impact of STN and GPi DBS as monotherapies and also comparative data across these two therapies on 7 cognitive domains. We provide evidence that, in appropriately screened PD patients, worsening of one or more cognitive functions is rare and subtle after DBS, without negative impact on quality of life, and that there is very little data supporting that STN DBS has a worse cognitive outcome than GPi DBS