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Objective: Low-frequency 4-12 Hz pallidal oscillations are being considered as potential physiomarkers for dystonia. We suggest investigating the multifractal properties of pallidal activity as an additional marker., Methods: We employed local field potentials (LFP) recordings from 23 patients with dystonia who were undergoing deep brain stimulation (DBS) surgery to explore the connection between disease severity and the multifractal characteristics of pallidal activity. Furthermore, we performed an analysis of LFP recordings from four patients, following the externalization of DBS lead electrodes, to investigate the impact of DBS and neck muscle vibration on multifractal parameters., Results: Greater dystonia severity exhibited a correlation with a narrower multifractal spectrum width but higher multifractal spectral asymmetry. Both GPi DBS and muscle vibration in dystonia patients expanded the multifractal spectrum width while restoring multifractal spectral symmetry. Notably, the threshold peak intensities for an increase in multifractal spectrum width substantially overlapped with the optimal volume of tissue activated. A broader multifractal spectrum during DBS corresponded to more favorable clinical outcomes., Conclusions: Multifractal properties of pallidal neuronal activity serve as indicators of neural dysfunction in dystonia., Significance: These findings suggest the potential of utilizing multifractal characteristics as predictive factors for the DBS outcome in dystonia., (Copyright © 2024 lInternational Federation of Clinical Neurophysiology. Published by Elsevier B.V. All rights reserved.)

Background: Pantothenate kinase-associated neurodegeneration (PKAN) is a type of inherited metabolic disorder caused by mutation in the PANK2 gene. The metabolic disorder mainly affects the basal ganglia region and eventually manifests as dystonia. For patients of dystonia, their dystonic symptom may progress to life-threatening emergency--status dystonicus., Objective: We described a case of a child with PKAN who had developed status dystonicus and was successfully treated with deep brain stimulation (DBS). Based on this rare condition, we analysed the clinical features of PKAN with status dystonicus and reviewed the reasonable management process of this condition., Conclusion: This case confirmed the rationality of choosing DBS for the treatment of status dystonicus. Meanwhile, we found that children with classic PKAN have a cluster of risk factors for developing status dystonicus. Once children diagnosed with similar neurodegenerative diseases are under status dystonicus, DBS can be active considered because it has showed high control rate of this emergent condition., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Background: Dystonia is a movement disorder characterized by sustained or intermittent muscle contractions that lead to involuntary postures or repetitive movements. Genetic mutations are being increasingly recognized as a cause of dystonia. Deep brain stimulation (DBS) is one of the limited treatment options available. However, there are varying reports on its efficacy in genetic dystonias. This systematic review of the characteristics of genetic dystonias treated with DBS and their outcomes aims to aid in the evaluation of eligibility for such treatment., Methods: We performed a PUBMED search of all papers related to genetic dystonias and DBS up until April 2022. In addition to performing a systematic review, we also performed a meta-analysis to assess the role of the mutation on DBS response. We included cases that had a confirmed genetic mutation and DBS along with pre-and post-operative BFMDRS., Results: Ninety-one reports met our inclusion criteria and from them, 235 cases were analyzed. Based on our analysis DYT-TOR1A dystonia had the best evidence for DBS response and Rapid-Onset Dystonia Parkinsonism was among the least responsive to DBS., Conclusion: While our report supports the role of genetics in DBS selection and response, it is limited by the rarity of the individual genetic conditions, the reliance on case reports and case series, and the limited ability to obtain genetic testing on a large scale in real-time as opposed to retrospectively as in many cases., Competing Interests: Declaration of competing interest The authors declare that there are no conflicts of interest relevant to this work., (Copyright © 2023. Published by Elsevier B.V.)

Background: Novel deep brain stimulation devices can record local field potentials (LFPs), which represent the synchronous synaptic activity of neuronal populations. The clinical relevance of LFPs in patients with dystonia remains unclear., Objectives: We sought to determine whether chronic LFPs recorded from the globus pallidus internus (GPi) were associated with symptoms of dystonia in children., Materials and Methods: Ten patients with heterogeneous forms of dystonia (genetic and acquired) were implanted with neurostimulators that recorded LFP spectral snapshots. Spectra were compared across parent-reported asymptomatic and symptomatic periods, with daily narrowband data superimposed in 24 one-hour bins., Results: Spectral power increased during periods of registered dystonic symptoms: mean increase = 102%, CI: (76.7, 132). Circadian rhythms within the LFP narrowband time series correlated with dystonic symptoms: for delta/theta-waves, correlation = 0.33, CI: (0.18, 0.47) and for alpha waves, correlation = 0.27, CI: (0.14, 0.40)., Conclusions: LFP spectra recorded in the GPi indicate a circadian pattern and are associated with the manifestation of dystonic symptoms., Competing Interests: Conflict of interest Carolina Gorodetsky reports a relationship with Medtronic, Inc that includes consulting or advisory and speaking and lecture fees. George M. Ibrahim reports a relationship with LivaNova that includes board membership and consulting or advisory. Alfonso Fasano reports a relationship with Medtronic, Inc, Abbott, and Boston Scientific that includes consulting or advisory and speaking and lecture fees. Lior M. Elkaim is an employee of Neuralink. The remaining authors report no conflict of interest., (Copyright © 2023 International Neuromodulation Society. Published by Elsevier Inc. All rights reserved.)

Objectives: Guanine nucleotide-binding protein alpha-activating activity polypeptide O (GNAO1) syndrome, a rare congenital monogenetic disorder, is characterized by a neurodevelopmental syndrome and the presence of dystonia. Dystonia can be very pronounced and even lead to a life-threatening status dystonicus. In a small number of pharmaco-refractory cases, deep brain stimulation (DBS) has been attempted to reduce dystonia. In this study, we summarize the current literature on outcome, safety, and outcome predictors of DBS for GNAO1-associated dystonia., Materials and Methods: We conducted a systematic review and meta-analysis on individual patient data. We included 18 studies describing 28 unique patients., Results: The mean age of onset of symptoms was 2.4 years (SD 3.8); 16 of 28 patients were male, and dystonia was nearly always generalized (20/22 patients). Symptoms were present before DBS for a median duration of 19.5 months, although highly variable, occurring between 3 and 168 months. The exact phenotype, genotype, and radiologic abnormalities varied and seemed to be of little importance in terms of DBS outcome. All studies described an improvement in dystonia. Our meta-analysis focused on pallidal DBS and found an absolute and relative improvement in Burke-Fahn-Marsden Dystonia Rating Scale (BFMDRS) of 32.5 points (37.9%; motor part; p = 0.001) and 5.8 points (21.5%; disability part; p = 0.043) at last follow-up compared with preoperative state; 80% of patients were considered responders (BFMDRS-M reduction by ≥25%). Although worsening over time does occur, an improvement was still observed in patients after >10 years. All reported cases of status dystonicus resolved after DBS surgery. Skin erosion and infection were observed in 18% of patients., Conclusion: Pallidal DBS can be efficacious and safe in GNAO1-associated dystonia., Competing Interests: Conflict of Interest The authors reported no conflict of interest., (Copyright © 2023 International Neuromodulation Society. Published by Elsevier Inc. All rights reserved.)

Objectives: Few studies have focused on subthalamic nucleus deep brain stimulation for refractory isolated dystonia, and the long-term outcomes are unclear. In this study, we evaluated the efficacy of subthalamic stimulation for generalized isolated dystonia for more than five years and explored the factors predicting clinical outcomes., Materials and Methods: A total of 16 patients with generalized isolated dystonia underwent a two-phase procedure for stimulation system implantation. After implanting the leads, we performed a test stimulation and observed the stimulation response. The severity of dystonia was assessed using a blinded rating of the Burke-Fahn-Marsden Dystonia Rating Scale based on videos recorded at scheduled times., Results: The mean follow-up time was 7.4 ± 2.2 years (5-12.5 years). The severity of dystonia improved significantly one year after surgery. The movement score decreased from 49.3 (40.9) points at baseline to 26.5 (43.5) points (-44.6%) at six months, 12.0 (22.5) points (-66.8%) at one year, 11.25 (17.6) points (-72.7%) at three years, and 12.5 (21.0) points (-72.6%) at the last follow-up. The improvement in motor symptoms resulted in a corresponding improvement in activities of daily living. Greater long-term outcomes were correlated with early stimulation responses, lower baseline movement scores, and female sex. When analyzed comprehensively, only the baseline movement score had meaningful predictive value for the outcome., Conclusions: Our results indicate that subthalamic stimulation is effective and durable in treating generalized isolated dystonia. The subthalamic nucleus may be an alternative target for the treatment of refractory dystonia. Patients with less severe motor symptoms may benefit more from this treatment., (Copyright © 2022 International Neuromodulation Society. Published by Elsevier Inc. All rights reserved.)

Introduction: Childhood dystonia is often nonresponsive to medications, and refractory cases are increasingly being treated with deep brain stimulation (DBS). However, many have noted that there is little consensus about when DBS should be offered, and there has been little examination of clinicians' decision-making process when determining whether to offer DBS for childhood dystonia., Objectives: This study aimed to identify and examine the factors considered by pediatric movement disorder specialists before offering DBS., Materials and Methods: Semistructured interviews (N = 29) with pediatric dystonia clinicians were conducted, transcribed, and coded. Using thematic content analysis, nine central themes were identified when clinicians were asked about key factors, clinical factors, and psychosocial factors considered before offering pediatric DBS., Results: Clinicians identified nine main factors. Five of these were classified primarily as clinical factors: early intervention and younger age (raised by 86% of respondents), disease progression and symptom severity (83%), etiology and genetic status (79%), clinicians' perceived risks and benefits of DBS for the patient (79%), and exhaustion of other treatment options (55%). The remaining four were classified primarily as psychosocial factors: social and family support (raised by 97% of respondents), patient and caregiver expectations about outcomes and understanding of DBS treatment (90%), impact of dystonia on quality of life (69%), and financial resources and access to care (31%)., Conclusions: Candidacy determinations, in this context, are complicated by an interrelation of clinical and psychosocial factors that contribute to the decision. There is potential for bias when considering family support and quality of life. Uncertainty of outcomes related to the etiology of dystonia makes candidacy judgments challenging. More systematic examination of the characteristics and criteria used to identify pediatric patients with dystonia who can significantly benefit from DBS is necessary to develop clear guidelines and promote the well-being of these children., (Copyright © 2021 International Neuromodulation Society. Published by Elsevier Inc. All rights reserved.)

Objectives: To evaluate the correlation between the pallidal local field potentials (LFPs) activity and the cortical oscillations (at rest and during several motor tasks) in two freely moving patients with generalized dystonia and pallidal deep brain stimulation (DBS)., Materials and Methods: Two women with isolated generalized dystonia were selected for bilateral globus pallidus internus (GPi) DBS. After the electrodes' implantation, cortical activity was recorded by a portable electroencephalography (EEG) system simultaneously with GPi LFPs activity, during several motor tasks, gait, and rest condition. Recordings were not performed during stimulation. EEG and LFPs signals relative to each specific movement were coupled together and grouped in neck/upper limbs movements and gait. Power spectral density (PSD), EEG-LFP coherence (through envelope of imaginary coherence operator), and 1/f exponent of LFP-PSD background were calculated., Results: In both patients, the pallidal LFPs PSD at rest was characterized by prominent 4-12 Hz activity. Voluntary movements increased activity in the theta (θ) band (4-7 Hz) compared to rest, in both LFPs and EEG signals. Gait induced a drastic raise of θ activity in both patients' pallidal activity, less marked for the EEG signal. A coherence peak within the 8-13 Hz range was found between pallidal LFPs and EEG recorded at rest., Conclusions: Neck/upper limbs voluntary movements and gait suppressed the GPi-LFPs-cortical-EEG coherence and differently impacted both EEG and LFPs low frequency activity. These findings suggest a selective modulation of the cortico-basal ganglia network activity in dystonia., (Copyright © 2022. Published by Elsevier Inc.)

Background: Deep brain stimulation of the internal globus pallidus effectively alleviates dystonia motor symptoms. However, delayed symptom control and a lack of therapeutic biomarkers and a single pallidal sweetspot region complicates optimal programming. Postoperative management is complex, typically requiring multiple, lengthy follow-ups with an experienced physician - an important barrier to widespread adoption in medication-refractory dystonia patients., Objective: Here we prospectively tested the best machine-predicted programming settings in a dystonia cohort treated with GPi-DBS against the settings derived from clinical long-term care in a specialised DBS centre., Methods: Previously, we reconstructed an anatomical map of motor improvement probability across the pallidal region using individual stimulation volumes and clinical outcomes in dystonia patients. We used this to develop an algorithm that tests in silico thousands of putative stimulation settings in de novo patients after reconstructing an individual, image-based anatomical model of electrode positions, and suggests stimulation parameters with the highest likelihood of optimal symptom control. To test real-life application, our prospective study compared results in 10 patients against programming settings derived from long-term care., Results: In this cohort, dystonia symptom reduction was observed at 74.9 ± 15.3% with C-SURF programming as compared to 66.3 ± 16.3% with clinical programming (p < 0.012). The average total electrical energy delivered (TEED) was similar for both the clinical and C-SURF programming (262.0 μJ/s vs. 306.1 μJ/s respectively)., Conclusion: Our findings highlight the clinical potential of machine-based programming in dystonia, which could markedly reduce the programming burden in postoperative management., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: FL reports grants from Boston Scientific not relevant to the submitted manuscript. MMR reports grants and personal fees from Boston Scientific and Medtronic, not relevant to the submitted work. MJR reports grants and personal fees from Boston Scientific, Medtronic and Zambon, not relevant to the submitted work. JV reports grants and personal fees from Medtronic, personal fees from St. Jude, grants and personal fees from Boston Scientific, personal fees from UCB, personal fees from Merz, personal fees from Allergan, personal fees from TEVA, personal fees from Novartis, personal fees from AbbVie and personal fees from Grünenthal, all outside the submitted work. All other authors report no competing interests., (Copyright © 2023 The Authors. Published by Elsevier Inc. All rights reserved.)

Background: There has been substantial controversy in the neuroethics literature regarding the extent to which deep brain stimulation (DBS) impacts dimensions of personality, mood, and behavior., Objective/hypothesis: Despite extensive debate in the theoretical literature, there remains a paucity of empirical data available to support or refute claims related to the psychosocial changes following DBS., Methods: A mixed-methods approach was used to examine the perspectives of patients who underwent DBS regarding changes to their personality, authenticity, autonomy, risk-taking, and overall quality of life., Results: Patients (n = 21) who were enrolled in adaptive DBS trials for Parkinson's disease, essential tremor, obsessive-compulsive disorder, Tourette's syndrome, or dystonia participated. Qualitative data revealed that participants, in general, reported positive experiences with alterations in what was described as 'personality, mood, and behavior changes.' The majority of participants reported increases in quality of life. No participants reported 'regretting the decision to undergo DBS.', Conclusion(s): The findings from this patient sample do not support the narrative that DBS results in substantial adverse changes to dimensions of personality, mood, and behavior. Changes reported as "negative" or "undesired" were few in number, and transient in nature., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 The Authors. Published by Elsevier Inc. All rights reserved.)

Introduction: Deep brain stimulation (DBS) is an established treatment in patients of various ages with pharmaco-resistant neurological disorders. Surgical targeting and postoperative programming of DBS depend on the spatial location of the stimulating electrodes in relation to the surrounding anatomical structures, and on electrode connectivity to a specific distribution pattern within brain networks. Such information is usually collected using group-level analysis, which relies on the availability of normative imaging resources (atlases and connectomes). Analysis of DBS data in children with debilitating neurological disorders such as dystonia would benefit from such resources, especially given the developmental differences in neuroimaging data between adults and children. We assembled pediatric normative neuroimaging resources from open-access datasets in order to comply with age-related anatomical and functional differences in pediatric DBS populations. We illustrated their utility in a cohort of children with dystonia treated with pallidal DBS. We aimed to derive a local pallidal sweetspot and explore a connectivity fingerprint associated with pallidal stimulation to exemplify the utility of the assembled imaging resources., Methods: An average pediatric brain template (the MNI brain template 4.5-18.5 years) was implemented and used to localize the DBS electrodes in 20 patients from the GEPESTIM registry cohort. A pediatric subcortical atlas, analogous to the DISTAL atlas known in DBS research, was also employed to highlight the anatomical structures of interest. A local pallidal sweetspot was modeled, and its degree of overlap with stimulation volumes was calculated as a correlate of individual clinical outcomes. Additionally, a pediatric functional connectome of 100 neurotypical subjects from the Consortium for Reliability and Reproducibility was built to allow network-based analyses and decipher a connectivity fingerprint responsible for the clinical improvements in our cohort., Results: We successfully implemented a pediatric neuroimaging dataset that will be made available for public use as a tool for DBS analyses. Overlap of stimulation volumes with the identified DBS-sweetspot model correlated significantly with improvement on a local spatial level (R = 0.46, permuted p = 0.019). The functional connectivity fingerprint of DBS outcomes was determined to be a network correlate of therapeutic pallidal stimulation in children with dystonia (R = 0.30, permuted p = 0.003)., Conclusions: Local sweetspot and distributed network models provide neuroanatomical substrates for DBS-associated clinical outcomes in dystonia using pediatric neuroimaging surrogate data. Implementation of this pediatric neuroimaging dataset might help to improve the practice and pave the road towards a personalized DBS-neuroimaging analyses in pediatric patients., Competing Interests: Declaration of Competing Interest AAK received honoraria from Medtronic and Boston Scientific, not related to this work. AK is a principal investigator in the STIM-CP trial, partly sponsored by Boston Scientific. JKK is a consultant to Medtronic, Boston Scientific, aleva and Inomed. LT serves as the vice president of the German Neurological Society. TAD has received speaker honoraria from Medtronic & Boston Scientific. The remaining authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 The Author(s). Published by Elsevier Inc. All rights reserved.)

Background: Among dystonia patients receiving globus pallidus internus (GPi) deep brain stimulation (DBS), long-term outcomes remain to be established. To report the long-term outcomes of GPi DBS in a patient cohort with idiopathic and acquired dystonia., Methods: In this long-term follow-up cohort, there were 4 patients with idiopathic dystonia and 2 patients with acquired dystonia. The Burke-Fahn-Marsden Dystonia Rating Scale was used to evaluate 6 consecutive patients preoperatively and at 6 months, 12 months, and the last follow-up. The relationship between etiology and clinical improvement was analyzed. Stimulation parameters were evaluated for similarities and differences among these patients., Results: The mean follow-up of our cohort was 65.3 months (median 40.5 months). The average improvement in the Burke-Fahn-Marsden Dystonia Rating Scale (mean ± SEM) were 56% ± 7.6, 67% ± 6.8 and 66% ± 9.7 at 6 months, 12 months, and the last follow-up, respectively. There was greater improvement during the long-term follow-up in the 4 patients with idiopathic dystonia than in the 2 patients with acquired dystonia. The 2 most ventral electrodes (contact 0 and 1) were activated in all 11 leads in this cohort. The average stimulation intensity, pulse width and frequency were 2.0 ± 0.24 mA, 252 ± 43 μs, and 99 ± 6.0 Hz, respectively., Conclusions: Isolated dystonia, either monogenic or idiopathic, usually responds better to GPi DBS than to acquired dystonia. Selection of patients by dystonia etiology, accurate placement of DBS leads in GPi targets, and proper stimulation programming are crucial to achieve better long-term outcomes., (Copyright © 2022 The Author(s). Published by Elsevier Inc. All rights reserved.)

Objective: The objective of this study was to evaluate the accuracy of the SureTune3 postoperative imaging software in determining the location of a deep brain stimulation (DBS) electrode based on clinical outcomes and the adverse effects (AEs) observed., Methods: Twenty-six consecutive patients with Parkinson disease (n = 17), essential tremor (n = 8), and dystonia (n = 1) who underwent bilateral DBS surgery (52 electrodes) were included in this study. Presurgical assessments were performed in all patients prior to surgery and at 3 and 6 months after surgery, using quality-of-life and clinical scales in each case. The SureTune3 software was used to evaluate the anatomical positioning of the DBS electrodes., Results: Following DBS surgery, motor and quality-of-life improvement was observed in all patients. Different AEs were detected in 12 patients, in 10 of whom (83.3%) SureTune3 related the symptoms to the positioning of an electrode. A clinical association was observed with SureTune3 for 48 of 52 (92.3%) electrodes, whereas no association was found between the AEs or clinical outcomes and the SureTune3 reconstructions for 4 of 52 electrodes (7.7%) from 4 different patients. In 2 patients, the contact chosen was modified based on the SureTune3 data, and in 2 cases, the software helped determine that second electrode replacement surgery was necessary., Conclusions: The anatomical position of electrodes analyzed with SureTune3 software was strongly correlated with both the AEs and clinical outcomes. Thus, SureTune3 may be useful in clinical practice, and it could help improve stimulation parameters and influence decisions to undertake electrode replacement surgery., (Copyright © 2022 Elsevier Inc. All rights reserved.)

Background: Deep brain stimulation of the internal globus pallidus (GPi DBS) is an invasive therapeutic modality intended to retune abnormal central nervous system patterns and relieve the patient of dystonic or other motor symptoms., Objectives: The aim of the presented research was to determine the neuroanatomical signature of GPi DBS modulation and its association with the clinical outcome., Methods: This open-label fixed-order study with cross-sectional validation against healthy controls analysed the resting-state functional MRI activity changes induced by GPi DBS in 18 dystonia patients of heterogeneous aetiology, focusing on both global (full brain) and local connectivity (local signal homogeneity)., Results: Compared to the switched-off state, the activation of GPi DBS led to the restoration of global subcortical connectivity patterns (in both putamina, diencephalon and brainstem) towards those of healthy controls, with positive direct correlation over large-scale cortico-basal ganglia-thalamo-cortical and cerebellar networks with the clinical improvement. Nonetheless, on average, GPi DBS also seemed to bring local connectivity both in the cortical and subcortical regions farther away from the state detected in healthy controls. Interestingly, its correlation with clinical outcome showed that in better DBS responders, local connectivity defied this effect and approached healthy controls., Conclusions: All in all, the extent of restoration of both these main metrics of interest towards the levels found in healthy controls clearly correlated with the clinical improvement, indicating that the restoration of network state towards more physiological condition may be a precondition for successful GPi DBS outcome in dystonia., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 The Author(s). Published by Elsevier Inc. All rights reserved.)

Hyperkinesias are heterogeneous involuntary movements that significantly differ in terms of clinical and semeiological manifestations, including rhythm, regularity, speed, duration, and other factors that determine their appearance or suppression. Hyperkinesias are due to complex, variable, and largely undefined pathophysiological mechanisms that may involve different brain areas. In this chapter, we specifically focus on dystonia, chorea and hemiballismus, and other dyskinesias, specifically, levodopa-induced, tardive, and cranial dyskinesia. We address the role of neurophysiological studies aimed at explaining the pathophysiology of these conditions. We mainly refer to human studies using surface and invasive in-depth recordings, as well as spinal, brainstem, and transcortical reflexology and non-invasive brain stimulation techniques. We discuss the extent to which the neurophysiological abnormalities observed in hyperkinesias may be explained by pathophysiological models. We highlight the most relevant issues that deserve future research efforts. The potential role of neurophysiological assessment in the clinical context of hyperkinesia is also discussed., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 International Federation of Clinical Neurophysiology. Published by Elsevier B.V. All rights reserved.)

Objective: Dystonia in pantothenate kinase-associated neurodegeneration (PKAN) is progressive despite medication. Deep brain stimulation (DBS) was reported to effectively provide symptom relief. No consensus exists in candidate and target selection for DBS. We aimed to demonstrate effectiveness of subthalamic DBS (STN-DBS) placement in pediatric patients with PKAN., Methods: We reviewed consecutive series of pediatric patients diagnosed with PKAN and treated with STN-DBS from 2016 to 2019 in our institution. Each case was described in detail. Preoperative and postoperative Burke-Fahn-Marsden Dystonia Rating Scale (BFMDRS) were assessed to evaluate functional improvement at follow-up., Results: Seven pediatric patients were included. Mean age of initial onset was 0.6 ± 0.5 years and presentation to clinics was 6.6 ± 1.3 years. Mean preoperative BFMDRS was 73.3 ± 3.5. Following STN-DBS, for mean follow-up duration of 13.0 ± 10.7 months, mean BFMDRS was 37.3 ± 12.6, translating to score improvement of 36.0 ± 12.9 (P < 0.001), and percentage improvement of 49.0 ± 18.0%., Conclusions: This case series demonstrated that STN-DBS is an effective symptom-based treatment for pediatric patients with PKAN., (Copyright © 2022. Published by Elsevier Inc.)

Dystonia and tremor frequently co-occur. In some cases, they have shared biological mechanisms, while in others dystonia and tremor are two comorbid conditions. The term "dystonic tremor" is used to describe tremor in those who have dystonia. Two mutually exclusive definitions of "dystonic tremor" were proposed. According to one definition, dystonic tremor is the tremor in the dystonic body part. An alternate definition of dystonic tremor entails irregular and jerky oscillations that have saw tooth appearance with or without overt dystonia. This paper outlines the differences in two definitions of dystonic tremor and identifies their limitations. Given the diverse views defining "dystonic tremor", this paper will use the term "tremor in dystonia". In addition, we will outline different ways to separate the subtypes of tremor in dystonia. Then we will discuss pathophysiological mechanisms derived from the objective measures and single neuron physiology analyses of tremor in dystonia. This article is part of the Special Issue "Tremor" edited by Daniel D. Truong, Mark Hallett, and Aasef Shaikh., (Copyright © 2022. Published by Elsevier B.V.)

Dystonia is a hyperkinetic movement disorder associated with loss of inhibition, abnormal plasticity, dysfunctional sensorimotor integration, and brain oscillatory dysfunctions at cortical and subcortical levels of the central nervous system. Hence, dystonia is considered a network disorder that can, in many cases, be efficiently treated by pallidal deep brain stimulation (DBS). Abnormal oscillatory activity has been identified across the motor circuit of patients with dystonia. Increased low frequency (LF) synchronization in the internal pallidum is the most prominent abnormality. LF oscillations have been associated with the severity of dystonic motor symptoms; they are suppressed by DBS and localized to the clinically most effective stimulation site. Although the origin of these pathologic changes in brain activity needs further clarifications, their characterization will help in adjusting DBS parameters for successful clinical outcome., (Copyright © 2022 Elsevier B.V. All rights reserved.)

Objective: Deep brain stimulation (DBS) is a frequently applied therapy in primary dystonia. For secondary dystonia, the effects can be less favorable. We share our long-term findings in 9 patients with severe secondary dystonia and discuss these findings in the light of the literature., Methods: Patients who had undergone globus pallidus internus (GPi)-DBS for secondary dystonia were included. Burke-Fahn-Marsden Dystonia Rating Scale (BFMDRS) scores, clinical improvement rates, follow-up periods, stimulation parameters and the need for internal pulse generator replacements were analyzed. The PubMed and Google Scholar databases were searched for articles describing GPi-DBS and subthalamic nucleus (STN)-DBS only for secondary dystonia cases. Keywords were "dystonia," "deep brain stimulation," "GPi," "dystonia," "deep brain stimulation," and "STN.", Results: A total of 9 secondary dystonia patients (5 male, 4 female) had undergone GPi-DBS with microelectrode recording in our units. The mean follow-up period was 29 months. The average BFMDRS score was 58.2 before the surgery, whereas the mean value was 36.5 at the last follow-up of the patients (mean improvement, 39%; minimum, 9%; maximum, 63%). In the literature review, we identified 264 GPi-DBS cases (mean follow-up, 19 months) in 72 different articles about secondary dystonia. The mean BFMDRS improvement rate was 52%. In 146 secondary dystonia cases, reported in 19 articles, STN-DBS was performed. The average follow-up period was 20 months and the improvement in BFMDRS score was 66%., Conclusions: Although GPi-DBS has favorable long-term efficacy and safety in the treatment of patients with secondary dystonia, STN seems a promising target for stimulation in patients with secondary dystonia. Further studies including a large number of patients, longer follow-up periods, and more homogenous patients are necessary to establish the optimal target for DBS in the management of secondary dystonias., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Objectives: Deep brain stimulation (DBS) is known to interfere with electrocardiographic (ECG) examinations. In emergency situations, such electrical interferences can not only thwart ECG diagnostics, but even induce an ECG pattern that causes the emergency medical service to initiate inadequate or even harmful therapy. Aim of this prospective study was to evaluate factors influencing ECG interpretation in DBS and to evaluate the susceptibility of ECG criteria 'frequency', 'rhythm', 'regularity', 'QRS-configuration', and 'ST-segment' on neurostimulation., Patients and Methods: In 33 DBS patients (17 male, 16 female, mean age 64 years), limb-, 12 channel-, Nehb, and adhesive paddle-lead ECG were performed in activated (n = 33) and deactivated (n = 31) stimulation mode during outpatient follow-up examinations. The examinations were carried out using three different ECG devices (two portable emergency ECG-monitor/defibrillation/pacer-devices, one stationary hospital device), resulting in 4096 ECG leads. Statistics have been based on regression analyses and on a maximum likelihood estimation regression model., Results: Monopolar settings were found to be a relevant factor interfering significantly more often with ECG recording than bipolar parameters (p < 0.0001). Due to recurring movement artefacts, deactivation of bipolar stimulation might even significantly worsen ECG quality (p < 0.0001). Interpretability of 'rhythm' (β = -0.088, p = 0.03) and 'frequency' (β = -0.110, p = 0.02) revealed significant negative correlation to the applied neurostimulation voltage. Nehb lead yielded in highest ECG interpretability., Conclusion: Bipolar neurostimulation mode barely affected the ECGs; furthermore, the suppression of motion artefacts by neurostimulation can improve ECG quality. If monopolar neurostimulation is required, at least, stimulation voltage should be as low as possible to obtain good stimulation results., (Copyright © 2021 Elsevier B.V. All rights reserved.)

Objectives: Lead placement for deep brain stimulation (DBS) is routinely performed using neuroimaging or microelectrode recording (MER). Recent studies have demonstrated that DBS under general anesthesia using an imaging-guided target technique ("asleep" DBS) can be performed accurately and effectively with lower surgery complication rates than the MER-guided target method under local anesthesia ("awake" DBS). This suggests that asleep DBS may be a more acceptable method. However, there is limited direct evidence focused on isolated dystonia using this method. Therefore, this study aimed to investigate the clinical outcomes and targeting accuracy in patients with dystonia who underwent asleep DBS., Materials and Methods: We examined 56 patients (112 leads) with isolated dystonia who underwent asleep DBS targeting in the globus pallidus internus (GPi) and subthalamic nucleus (STN). The Burke-Fahn-Marsden Dystonia Rating Scale (BFMDRS) scores were assessed preoperatively and at 12-month follow-up (12 m-FU). The lead accuracy was evaluated by comparing the coordinates of the preoperative plan with those of the final electrode implantation location. Other measures analyzed included stimulation parameters and adverse events (AEs)., Results: For both GPi and STN cohorts, mean BFMDRS motor scores were significantly lower at 12 m-FU (8.9 ± 10.9 and 4.6 ± 5.7 points) than at baseline (22.6 ± 16.4 and 16.1 ± 14.1 points, p < 0.001). The mean difference between the planned target and the distal contact of the leads was 1.33 ± 0.54 mm for the right brain electrodes and 1.50 ± 0.57 mm for the left, determined by Euclidian distance. No perioperative complications or AEs related to the device were observed during the complete follow-up. However, AEs associated with stimulation occurred in 12 and 6 patients in the GPi and STN groups, respectively., Conclusions: Asleep DBS may be an accurate, effective, and safe method for treating patients with isolated dystonia regardless of the stimulation target., (© 2020 International Neuromodulation Society.)

Objective: Primary cervical dystonia (CD) is characterized by abnormal contractions of neck muscles. Globus pallidus internus deep brain stimulation (GPi-DBS) is recognized as an effective therapy for patients with refractory CD, but the prognostic factors need further research. Our study investigated the predictive factors of clinical outcomes in CD patients who underwent GPi-DBS., Patients and Methods: Patients (n = 23) who underwent GPi-DBS at Chinese PLA General Hospital from March 2012 to April 2018 were included in our analysis. Their scores of Toronto Western Spasmodic Torticollis Rating Scale (TWSTRS) and Tsui were acquired at baseline and at the last follow-up visit. Percent improvement in these scores were compared between the categorical variables. Correlations between outcomes and continuous demographic and clinical variables were calculated., Results: Patients showed significant improvement in TWSTRS total (55.71 %), severity (48.75 %), disability (57.05 %), pain (63.67 %) scores and total Tsui score (46.07 %, all P ﹤0.001). Follow-up duration was positively correlated with percent improvement in TWSTRS total (rho = 0.594, P =  0.003), severity (rho = 0.581, P =  0.004) and disability (rho = 0.470, P =  0.023) scores. No significant differences in the outcomes were found between any pair of the categorical variables., Conclusions: Follow-up duration was the only independent factor correlated to the outcomes of GPi-DBS for CD patients. However, follow-up duration is an indefinite factor prior to surgery, thus further studies are needed before the final conclusions of prognostic factors are established., Competing Interests: Declaration of Competing Interest We do not have any conflicts of interest., (Copyright © 2020 Elsevier B.V. All rights reserved.)

Background: Glioblastoma (GBM) is the most common aggressive malignant primary brain tumor, rarely concurrent in patients who require deep brain stimulation (DBS) implants. Despite the high incidence of these circumstances alone, the coexistence of both in a patient has been seldom reported. In this paper, we report a case of a patient suffering from a movement disorder treated with DBS who developed a GBM., Case Description: A patient with bilateral DBS of the globus pallidus internus for refractory secondary dystonia developed a GBM close to the electrode leads, 2.5 years after implantation. The clinical findings, medical management and pitfalls, and possible relationship between the DBS device and the tumor development are discussed. We withdrew the system to perform brain magnetic resonance imaging safely. This revealed an extended lesion that was biopsied. The removal led to a clinical worsening that resulted in fatality, without the possibility of receiving adjuvant treatment. The available literature shows similar management, which depends mainly on the stimulation system used., Conclusions: We advise the use of magnetic resonance imaging-safe devices; otherwise, we recommend keeping the system and proceeding with computed tomography imaging for diagnostic and management if necessary. The true relationship between chronic DBS stimulation and GBM is to be clarified., (Copyright © 2019 Elsevier Inc. All rights reserved.)

Objective: The globus pallidus internus (GPi) and subthalamic nucleus (STN) are therapeutic targets for deep brain stimulation (DBS) in the treatment of isolated dystonia. We conducted a meta-regression analysis on long-term studies of bilateral DBS in the GPi and STN to compare the relative effects of the 2 approaches., Methods: We systematically searched the PubMed, Embase, and Cochrane Controlled Register of Trials databases to identify studies reporting the treatment outcomes of GPi DBS and STN DBS for isolated dystonia. The primary outcome measure was the change in the Burke-Fahn-Marsden dystonia rating scale movement score between the baseline and follow-up evaluations. We performed a regression analysis using a random effects model., Results: A total of 42 follow-up evaluations (30 for GPi and 12 for STN) nested in 19 studies (16 of GPi and 3 of STN) were included in our analysis. The results from univariate regression analysis suggested that shorter disease duration and STN stimulation were associated with a greater standardized change in the Burke-Fahn-Marsden dystonia rating scale movement score. On combining the factors into 1 model, only the disease duration remained significant. The regression analysis results of the GPi and STN subgroups revealed more persistent improvement after STN stimulation., Conclusions: A shorter disease duration correlated positively with better DBS outcomes. The STN appeared to be an optimized stimulation target for the treatment of isolated dystonia, although randomized controlled trials are needed to compare the treatment efficacy of GPi DBS and STN DBS., (Copyright © 2019 Elsevier Inc. All rights reserved.)

Objective: Finding a non-invasive biomarker for Globus Pallidus interna Deep Brain Stimulation (GPi-DBS) efficacy. Dystonia heterogeneity leads to a wide variety of clinical response to GPi-DBS, making it hard to predict GPi-DBS efficacy for individual patients., Methods: EEG-EMG recordings of twelve dystonia patients who received bilateral GPi-DBS took place pre- and 1 year post-surgery ON and OFF stimulation, during a rest, pinch, and flexion task. Dystonia severity was assessed using the BFMDRS and TWSTRS (pre- and post-surgery ON stimulation). Intermuscular coherence (IMC) and motorcortex corticomuscular coherence (CMC) were calculated. Low frequency (4-12 Hz) and beta band (13-30 Hz) peak coherences were studied., Results: Dystonia severity improved after 1 year GPi-DBS therapy (BFMDRS: 30%, median 7.8 (IQR 3-10), TWSTRS: 22%, median 6.8 (IQR 4-9)). 86% of IMC were above the 95% confidence limit. The highest IMC peak decreased significantly with GPi-DBS in the low frequency and beta band. Low frequency and beta band IMC correlated partly with dystonia severity and severity improvement. CMC generally were below the 95% confidence limit., Conclusions: Peak low frequency IMC functioned as biomarker for GPi-DBS efficacy, and partly correlated with dystonia severity., Significance: IMC can function as biomarker. Confirmation in a larger study is needed for use in clinical practice., (Copyright © 2019 International Federation of Clinical Neurophysiology. Published by Elsevier B.V. All rights reserved.)

Objective: To outline the current knowledge of (sub)cortical oscillations in Parkinson's Disease (PD) and dystonia, and to quantitatively summarize the results of direct comparisons of local oscillatory power between both diseases in the resting state, without medication or stimulation, in both the low-frequency (LF, ±4-12 Hz) and beta (±13 to ∼30 Hz) range., Methods: Eight relevant studies were included. Recordings from 127 dystonia-, and 144 PD-patient hemispheres were analyzed. Ratios of LF and beta power between diseases were obtained., Results: Beta oscillations in dystonia were lower when compared to beta oscillations in PD, ratio = 0.72, Z = 3.56, p = 0.0004, 95% CI [0.60, 0.86]. Subgroup analyses showed significant differences only in the GPi, whilst conflicting evidence was shown in the STN. LF oscillations in PD were lower when compared to LF oscillations in dystonia, ratio = 0.77, Z = 2.45, p = 0.01, 95% CI [0.63, 0.95]. Subgroup analyses showed significant differences in the GPi and the STN, but not in the M1., Conclusions: LF and beta oscillations are present in the resting-state motor network of both PD and dystonia patients. However, the power distribution of those oscillations differs between diseases., Significance: This meta-analysis provides high-level evidence which supports the presence of exaggerated oscillations across the parkinsonian/dystonic motor networks., (Copyright © 2019 International Federation of Clinical Neurophysiology. Published by Elsevier B.V. All rights reserved.)

Objective: Implantation of deep brain stimulation (DBS) electrodes requires stereotactic imaging. Stereotactic magnetic resonance imaging (MRI) for DBS surgery has become more popular and intraoperative MRI scanners have become more available. We report on our cohort of movement disorder patients who underwent intraoperative stereotactic MRI-only DBS electrode implantation., Methods: A review of our DBS database for eligible patients over a study period of 8 years was performed. Stereotactic accuracy was calculated as a directional error and the Euclidean distance between planned and controlled electrode positions. Number and choice of microelectrodes, procedural times and complications were documented., Results: n = 86 surgeries in n = 81 patients with Parkinson's Disease (PD), essential tremor and dystonia were performed and n=167 electrodes were implanted. Mean Euclidean distance between planned and controlled target was 2.1mm (±0.6). The directional error showed that electrodes were implanted more medial (0.3mm ± 0.9), posterior (0.5mm ± 1.0) and inferior (0.6mm ±1.0) compared to plan. There were no significant differences for stereotactic accuracy between targets, hemispheres or order of implantation. No significant correlations between Euclidean distance and number of microelectrode tracts or volume of intracranial air were observed. N = 539 microelectrodes were applied. In 28.7% non-center trajectories were chosen. Length of tremor (-61 minutes) and PD (-121 minutes) surgeries could be reduced significantly over the course of the study period. N = 1 (1.2%) intracranial hemorrhage occurred. N = 1 (0.6%) electrode had to be repositioned for lack of clinical effect., Conclusion: Intraoperative stereotactic MRI for DBS surgery is feasible with high stereotactic accuracy and low rates of complication., (Copyright © 2018 Elsevier Inc. All rights reserved.)

Introduction: Growing evidence suggests that pallidal deep brain stimulation represents a potential new therapeutic avenue in tardive dystonia/dyskinesia, but controlled and blinded randomized studies (RCT) are missing. The present RCT compares dystonia/dyskinesia severity of pallidal neurostimulation in patients with tardive dystonia using a delayed-start design paradigm., Methods: Dystonia/dyskinesia severity was assessed via blinded videos following pallidal neurostimulation at 3 (blinded phase) and 6 months (open extension phase). Primary endpoint was the percentage change of dystonia severity (Burke-Fahn-Marsden-Dystonia-Rating-Scale, BFMDRS) at 3 months between active vs. sham neurostimulation using blinded-video assessment. Secondary endpoints comprised clinical rating scores for movement disorders. Clinicaltrials.gov NCT00331669., Results: Twenty-five patients were randomized (1:1) to active (n = 12) or sham neurostimulation (n = 13). In the intention-to-treat analyses the between group difference of dystonia severity (BFMDRS) between active vs. sham stimulation was not significant at 3 months. Three months post-randomisation dystonia severity improved significantly within the neurostimulation by 22.8% and non-significantly within the sham group (12.0%) compared to their respective baseline severity. During the open-label extension with both groups being actively treated, significant and pronounced improvements of 41.5% were observed via blinded evaluation. Adverse events (n = 10) occurred in 10/25 of patients during the 6 months, mostly related to surgical implantation of the device; all resolved without sequelae., Conclusion: The primary endpoint of this randomized trial was not significant, most likely due to incomplete recruitment. However, pronounced improvements of most secondary endpoints at 3 and 6 months provide evidence for efficacy and safety of pallidal neurostimulation in tardive dystonia., (Copyright © 2018 Elsevier Inc. All rights reserved.)

Background: Off state toe dystonia (TD) is a symptom frequently encountered in Parkinson's disease (PD), but little is known about its evolution after subthalamic nucleus deep brain stimulation (STN-DBS)., Objective: To analyze the prevalence and the evolution of TD in PD patients candidate to STN-DBS., Methods: Individual data of consecutive 130 PD patients who underwent STN-DBS between 2010 and 2015 were collected., Results: Data were successfully collected in 95 patients. TD affect 45.3% of the patients in our cohort. TD was present in 32.7% of patients before surgery and was alleviated by STN-DBS in 48% of the cases. Motor improvement provided by STN-DBS, levodopa-equivalent treatment diminution after surgery, disease duration or age at the time of surgery were not predictive of TD evolution. A younger age at PD diagnosis was significantly associated with TD resolution., Conclusion: STN-DBS is partially efficient for TD but its evolution seems independent of significant predictive factors., (Copyright © 2018 Elsevier B.V. All rights reserved.)

Background: Deep brain stimulation (DBS) is an established treatment for generalized dystonia. However, the DBS device is sometimes removed owing to hardware complications. We present 4 cases of generalized dystonia treated with radiofrequency lesioning through DBS electrodes., Case Description: Four patients, 3 men and 1 woman (age range, 34-44 years), underwent DBS for generalized dystonia and subsequently developed complications, such as infection, necessitating removal of the devices. As stopping the stimulation caused recurrence of uncontrollable symptoms, radiofrequency lesioning was performed through the DBS electrodes under local anesthesia, and the DBS systems were removed under local or generalized anesthesia thereafter. The procedures performed were as follows: 2 patients had bilateral pallidotomy, 1 patient had unilateral pallidotomy, and 1 patient had pallidotomy and ipsilateral thalamotomy. As a result, in 4 patients, the dystonic symptoms did not worsen even after removal of the DBS systems during a follow-up period of 1-12 years. However, 1 patient had a small hemorrhage, and 2 patients showed recurrence of dystonia., Conclusions: Radiofrequency lesioning with DBS electrodes is feasible in cases of generalized dystonia when the DBS leads have to be removed., (Copyright © 2018 Elsevier Inc. All rights reserved.)

Background: Although pallidal deep brain stimulation (GPi-DBS) is an effective treatment for dystonia, it may cause important stimulation-induced side-effects such as hypokinetic dysarthria or stuttering. However, the reasons behind the occurrence of these side-effects remain unknown., Objective: To objectively investigate the impact of GPi-DBS on patients with dystonia on speech fluency, intelligibility, and key aspects of hyperkinetic and hypokinetic dysarthria., Methods: Speech was systematically evaluated in 19 dystonic patients with GPi-DBS. Each patient was tested twice within one day in both the GPi-DBS ON and GPi-DBS OFF stimulation conditions. A control sample of 19 matched healthy speakers underwent the same speech assessment., Results: We observed an improvement of hyperkinetic dysarthria symptoms in 47% and an aggravation of hypokinetic dysarthria symptoms in 26% of patients with the GPi-DBS switched ON. A higher stimulus intensity was found in a group of patients in whom the hypokinetic dysarthria worsened with the GPi-DBS ON when compared to other dystonic patients (p = 0.02). Furthermore, we revealed a significant increase of dysfluent words in the GPi-DBS ON when compared to OFF condition (p = 0.001) associated with the shorter distance of the active contact localization along the medio-lateral direction (r = -0.70, p = 0.005)., Conclusion: This study provides evidence of dualistic effects of GPi-DBS on speech in dystonia manifested as an improvement of hyperkinetic or a deterioration of hypokinetic dysarthria. Our findings suggest that lower stimulation parameters and placement of active contacts more laterally in the internal globus pallidus should be preferred to avoid the possible side effects of hypokinetic dysarthria and dysfluency., (Copyright © 2018 Elsevier Inc. All rights reserved.)

Multiple system atrophy is a progressive neurodegenerative disease characterized by the association of autonomic failure and a movement disorder that consist of either a hypokinetic movement disorder or a cerebellar syndrome or both. In addition to these core characteristics other movement disorders (e.g. dystonia, myoclonus, spasticity), and neuropsychiatric symptoms (e.g. depression, cognitive dysfunction) may occur in the course of the disease and can severely impair patients' quality of live. To date no causal therapy is available and therefore symptomatic treatment plays a pivotal role in patient care. In this article we provide an overview of frequent clinical symptoms and their symptomatic treatment options., (Copyright © 2017 Elsevier B.V. All rights reserved.)

Objectives: To report Somatosensory Evoked Potentials (SEPs) and Central Motor Conduction Times (CMCT) in children with dystonia and to test the hypothesis that these parameters predict outcome from Deep Brain Stimulation (DBS)., Methods: 180 children with dystonia underwent assessment for Globus pallidus internus (GPi) DBS, mean age 10 years (range 2.5-19). CMCT to each limb was calculated using Transcranial Magnetic Stimulation. Median and posterior tibial nerve SEPs were recorded over contralateral and midline centro-parietal scalp. Structural abnormalities were assessed with cranial MRI. One-year outcome from DBS was assessed as percentage improvement in Burke-Fahn-Marsden Dystonia Rating Scale (BFMDRS-m)., Results: Abnormal CMCTs and SEPs were found in 19% and 47% of children respectively and were observed more frequently in secondary than primary dystonia. Of children proceeding to DBS, better outcome was seen in those with normal (n = 78/89) versus abnormal CMCT (n = 11/89) (p = 0.002) and those with normal (n = 35/51) versus abnormal SEPs (n = 16/51) (p = 0.001). These relationships were independent of dystonia aetiology and cranial MRI findings., Conclusions: CMCTs and SEPs provide objective evidence of motor and sensory pathway dysfunction in children with dystonia and relate to DBS outcome., Significance: CMCTs and SEPs can contribute to patient selection and counselling of families about potential benefit from neuromodulation for dystonia., (Copyright © 2017 International Federation of Clinical Neurophysiology. Published by Elsevier B.V. All rights reserved.)

Objective: To investigate cortical activity using scalp EEG in patients with isolated dystonia treated with chronic deep brain stimulation (DBS), on and off stimulation., Methods: We analyzed 64-channel scalp EEG in 12 isolated dystonia patients treated with chronic DBS (7 generalized, 5 cervical/segmental; 7 globus pallidus (GP), 5 subthalamic nucleus (STN)), and 20 healthy age-matched controls. Recordings during rest and movement task, and clinical motor scores, were collected with DBS-on and during a 90-min DBS washout., Results: Resting state alpha power in the dominant (or contralateral to more dystonic side) motor cortex channel during DBS was comparable to healthy controls, but it increased when DBS was stopped. Resting state and movement-related alpha coherence between bilateral motor cortex channels was increased off DBS., Conclusions: Chronic DBS reduces exaggerated alpha oscillations and interhemispheric alpha coherence in the motor cortex of patients with isolated dystonia., Significance: These findings complement related studies in Parkinson's disease and support the view that network desynchronization is a prominent mechanism of DBS in movement disorders., (Copyright © 2017 International Federation of Clinical Neurophysiology. Published by Elsevier B.V. All rights reserved.)

Dystonia is a heterogeneous disorder characterized by involuntary muscle contractions, twisting movements, and abnormal postures in various body regions. It is widely accepted that the basal ganglia are involved in the pathogenesis of dystonia. A growing body of evidence, however, is challenging the traditional view and suggest that the cerebellum may also play a role in dystonia. Studies on animals indicate that experimental manipulations of the cerebellum lead to dystonic-like movements. Several clinical observations, including those from secondary dystonia cases as well as neurophysiologic and neuroimaging studies in human patients, provide further evidence in humans of a possible relationship between cerebellar abnormalities and dystonia. Claryfing the role of the cerebellum in dystonia is an important step towards providing alternative treatments based on noninvasive brain stimulation techniques., (Copyright © 2018 Elsevier B.V. All rights reserved.)

Introduction: Deep Brain Stimulation (DBS) is an effective treatment extended broadly to many neurological and psychiatric disorders. Nevertheless, complications may arise during DBS procedures or following implantation due to implanted hardware. This may result in both minor and major adverse events that may necessitate hardware removal and/or compromise maximal therapeutic benefit for the patient., Objectives and Methods: To identify relevant literature on hardware-related complications from DBS procedures by performing a systematic review, and propose how to identify at-risk group and possible preventive approaches., Results: Of 4592 abstract screened, 96 articles fulfilled the selection criteria and were reviewed. Overall, the most common hardware-related complications were infections (5.12% of patients), followed by lead migration (1.60%), fracture or failure of the lead or other parts of the implant (1.46% and 0.73%, respectively), IPG malfunctions (1.06% of patients), and skin erosions without infections (0.48% of patients). New indications for DBS, including Tourette's syndrome, cluster headache, and refractory partial epilepsy, were found to bear a higher incidence of hardware-related infections than established indications such as Parkinson's disease. The highest rate of lead fracture or failure was found in dystonia patients (4.22%). Ultimately, the highest rate of pain at the implantation sites was found in refractory partial epilepsy patients (16.55%)., Conclusion: Our analysis identified a variety of potential hardware-related complications among patients who underwent DBS procedures. Patients who were at risk of complications, such as patients with dystonia and off-label indications (e.g. Tourette's syndrome) should be informed prior to surgery and closely followed thereafter., (Copyright © 2017 Elsevier Inc. All rights reserved.)

Background: Template and atlas guidance are fundamental aspects of stereotactic neurosurgery. The recent availability of ultra-high field (7 Tesla) magnetic resonance imaging has enabled in vivo visualization at the submillimeter scale. In this Doing More with Less article, we describe our experiences with integrating ultra-high field template data into the clinical workflow to assist with target selection in deep brain stimulation (DBS) surgical planning., Methods: The creation of a high-resolution 7T template is described, generated from group data acquired at our center. A computational workflow was developed for spatially aligning the 7T template with standard clinical data and furthermore, integrating the derived imaging volumes into the surgical planning workstation., Results: We demonstrate that our methodology can be effective for assisting with target selection in 2 cases: unilateral internal pallidum DBS for painful dystonia and bilateral subthalamic nucleus DBS for Parkinson's disease., Conclusions: In this article, we have described a workflow for the integration of high-resolution in vivo ultra-high field templates into the surgical navigation system as a means to assist with DBS planning. The method does not require any additional cost or time to the patient. Future work will include prospectively evaluating different templates and their impact on target selection., (Crown Copyright © 2017. Published by Elsevier Inc. All rights reserved.)

Wilson disease (WD) is a potentially treatable neurodegenerative disorder. In the majority of cases, treatment with drugs that induce a negative copper balance (usually chelators or zinc salts) leads to improvements in liver function and neurologic signs. However, some patients show severe neurologic symptoms at diagnosis, such as tremor, dystonia, parkinsonism, and chorea. In this patient group, some neurologic deficits may persist despite adequate treatment, and further neurologic deterioration may be observed after treatment initiation. Such patients may require additional treatment to alleviate neurologic symptoms. Apart from general recommendations for WD anticopper treatment, there are currently no guidelines for managing neurologic symptoms in WD. The aim of this chapter is to summarize possible treatments of neurologic symptoms in WD based on the presently available medical literature., (© 2017 Elsevier B.V. All rights reserved.)

Background: Postoperative surgical-site infections (SSIs) are a common complication after deep brain stimulation (DBS) surgery, occurring at a quoted rate of approximately 1%-9%. Intraoperative vancomycin powder has demonstrated efficacy in reducing SSIs after cranial and spinal surgery; however, its use during DBS surgery has yet to be established. In this study, we describe the senior author's experience with the use of intraoperative vancomycin powder to prevent SSIs after DBS surgery., Methods: We retrospectively examined the incidence of SSI in 297 patients who underwent DBS surgery at the Mount Sinai Health System from September 2012 to December 2015. All patients underwent a uniform perioperative antiseptic protocol, including thorough skin cleansing, intravenous anticephalosporin antibiotics, copious irrigation, and the application of topical vancomycin powder (1 g) before skin closure. Patient information was obtained through a review of electronic medical records. Primary outcome was the incidence of SSI, which was defined per the standards of the Centers for Disease Control and Prevention and confirmed with wound cultures., Results: Four patients developed clinical signs and symptoms of SSI (1.3%); all were men with Parkinson disease. The primary organism responsible was Staphylococcus aureus (75%). Two patients presented with neurostimulator infections, and 2 presented with parietal connector-site infections between 2 months and 1 year after initial surgery. No patients in our series developed topical or systemic reactions attributable to the use of vancomycin powder., Conclusions: In our experience, vancomycin powder has demonstrated safety and efficacy as an adjunct medication for infection prophylaxis after DBS surgery. Further prospective studies with larger patient cohorts are warranted., (Copyright © 2016 Elsevier Inc. All rights reserved.)

Background: Deep brain stimulation (DBS) of the globus pallidus interna is an effective tool for the treatment of dystonia with possible distant effects reaching beyond the basal ganglia network., Aim: We analyzed the cortical silent period (CoSP) to test inhibitory circuits at the cortical level, and the cutaneous silent period (CuSP) and the H-reflex to test inhibitory circuits at the spinal level., Methods: The upper limb muscles of 16 patients (9F, aged 54±(SD)16years) with generalized (N=9) and cervical (N=7) dystonia treated with DBS bilaterally were examined by the CoSP, CuSP and H-reflex in two states with random order: (i) in DBS ON and (ii) in DBS OFF condition two hours later, and compared with healthy controls., Results: While the CuSP and H-Reflex did not differ between groups and remained unaffected by DBS, the CoSP was influenced significantly in dystonia. The CoSP onset latency was shortened (p<0.05 corrected) and the CoSP duration prolonged (p<0.01 corrected) in ON versus OFF condition. This effect was especially larger in generalized or phasic type of dystonia. Compared to healthy controls, the CoSP latency and duration became shorter in patients during the OFF condition only., Conclusion: The pallidal DBS did not affect the spinal inhibitory circuitry in dystonia. However, the abnormally low cortical inhibition was normalized after DBS possibly offering more efficient suppression of aberrant dystonic movements., (Copyright © 2016 Elsevier B.V. All rights reserved.)