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Background: Deep Brain Stimulation (DBS) is FDA-approved for several movement disorders; such as Parkinson's disease, dystonia, and neuropsychiatric disorders. There are various reports of Body mass index (BMI) changes following different DBS targets in various disorders., Aim: A comprehensive systematic review and meta-analysis were conducted to investigate the impact of DBS on patients' Body Mass Index (BMI) and provide an in-depth overview of its underlying mechanisms., Materials and Methods: We conducted research according to PRISMA guidelines. Our study assessed comprehensively electronic databases, including Pubmed, Scopus, Embase, web of science, and the Cochrane Library, up to May 2024. The random-effect model analysis was performed by the Comprehensive Meta-analysis software (CMA) version 3.0. As well, Cochran's Q test was used to determine the statistical heterogeneity of included studies., Result: This systematic review ultimately included 49 studies, 46 of which entered the meta-analysis. The total number of patients was 1478, consisting of Parkinson's disease (PD), dystonia, and the obsessive compulsive disorder (OCD) patients. The most common DBS target was subthalamic nucleus, followed by globus pallidus internus (GPi). Our meta-analysis depicted the BMI of participants significantly mount after DBS electrode implantation (SMD = -0.542, 95%CI: -0.678 to -0.406, and P-value < 0.001). However, moderate to high heterogeneity was detected among the studies (I 2  = 67.566%). Additionally, the Daily energy intake (DEI) of patients significantly decreased after DBS (SMD: 0.457, 95%CI; 0.205 to 0.709, and P-value < 0.001)., Conclusion: STN and GPi DBS can lead to weight gain through distinct central pathways in various movement and neuropsychiatric disorders, posing a potential risk for obesity, insulin resistance, and metabolic syndrome., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Deep brain stimulation (DBS), a method in which electrical stimulation is delivered to specific areas of the brain, is an effective treatment for managing symptoms of a number of neurological and neuropsychiatric disorders. Clinical access to neural circuits during DBS provides an opportunity to study the functional link between neural circuits and behavior. This review discusses how the use of DBS in Parkinson's disease and dystonia has provided insights into the brain networks and physiological mechanisms that underlie motor control. In parallel, insights from basic science about how patterns of electrical stimulation impact plasticity and communication within neural circuits are transforming DBS from a therapy for treating symptoms to a therapy for treating circuits, with the goal of training the brain out of its diseased state.

Deep brain stimulation (DBS) surgery is an established and effective treatment for several movement disorders (tremor, Parkinson's disease, and dystonia), and is under investigation in numerous other neurological and psychiatric disorders. However, the origins and development of this neurofunctional technique are not always well understood and recognized. In this mini-review, we review the history of DBS, highlighting important milestones and the most remarkable protagonists (neurosurgeons, neurologists, and neurophysiologists) who pioneered and fostered this therapy throughout the 20th and early 21st century. Alongside DBS historical markers, we also briefly discuss newer developments in the field, and the future challenges which accompany such progress., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Elena Moro reports a relationship with Medtronic Inc that includes: consulting or advisory. Elena Moro reports a relationship with Ipsen that includes: funding grants. Elena Moro reports a relationship with AbelsonTaylor Inc that includes: funding grants. Elena Moro reports a relationship with French Association for Parkinson's Disease that includes: funding grants. If there are other authors, they 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. Published by Elsevier Ltd.)

A neurological condition called dystonia results in abnormal, uncontrollable postures or movements because of sporadic or continuous muscular spasms. Several varieties of dystonia can impact people of all ages, leading to severe impairment and a decreased standard of living. The discovery of genes causing variations of single or mixed dystonia has improved our understanding of the disease's etiology. Genetic dystonias are linked to several genes, including pathogenic variations of VPS16, TOR1A, THAP1, GNAL, and ANO3. Diagnosis of dystonia is primarily based on clinical symptoms, which can be challenging due to overlapping symptoms with other neurological conditions, such as Parkinson's disease. This review aims to summarize recent advances in the genetic origins and management of focal dystonia.

Introduction: Deep brain stimulation (DBS) is a routine neurosurgical procedure utilized to treat various movement disorders including Parkinson's disease (PD), essential tremor (ET), and dystonia. Treatment efficacy is dependent on stereotactic accuracy of lead placement into the deep brain target of interest. However, brain shift attributed to pneumocephalus can introduce unpredictable inaccuracies during DBS lead placement. This study aimed to determine whether intracranial air is associated with brain shift in patients undergoing staged DBS surgery., Methods: We retrospectively evaluated 46 patients who underwent staged DBS surgery for PD, ET, and dystonia. Due to the staged nature of DBS surgery at our institution, the first electrode placement is used as a concrete fiducial marker for movement in the target location. Postoperative computed tomography (CT) images after the first electrode implantation, as well as preoperative, and postoperative CT images after the second electrode implantation were collected. Images were analyzed in stereotactic targeting software (BrainLab); intracranial air was manually segmented, and electrode shift was measured in the x, y, and z plane, as well as a Euclidian distance on each set of merged CT scans. A Pearson correlation analysis was used to determine the relationship between intracranial air and brain shift, and student's t test was used to compare means between patients with and without radiographic evidence of intracranial air., Results: Thirty-six patients had pneumocephalus after the first electrode implantation, while 35 had pneumocephalus after the second electrode implantation. Accumulation of intracranial air following the first electrode implantation (4.49 ± 6.05 cm3) was significantly correlated with brain shift along the y axis (0.04 ± 0.35 mm; r (34) = 0.36; p = 0.03), as well as the Euclidean distance of deviation (0.57 ± 0.33 mm; r (34) = 0.33; p = 0.05) indicating statistically significant shift on the ipsilateral side. However, there was no significant correlation between intracranial air and brain shift following the second electrode implantation, suggesting contralateral shift is minimal. Furthermore, there was no significant difference in brain shift between patients with and without radiographic evidence of intracranial air following both electrode implantation surgeries., Conclusion: Despite observing volumes as high as 22.0 cm3 in patients with radiographic evidence of pneumocephalus, there was no significant difference in brain shift when compared to patients without pneumocephalus. Furthermore, the mean magnitude of brain shift was &lt;1.0 mm regardless of whether pneumocephalus was presenting, suggesting that intracranial air accumulation may not produce clinical significant brain shift in our patients., (© 2024 S. Karger AG, Basel.)

Abnormal skull shape has been reported in brain disorders. However, no studies have investigated cranial geometry in neurodegenerative disorders. This study aimed to evaluate the cranial geometry of patients with dystonia or Parkinson's disease (PD). Cranial computed tomography images of 36 patients each with idiopathic dystonia (IDYS), PD, and chronic subdural hematoma (CSDH) were analyzed. Those with IDYS had a significantly higher occipital index (OI) than those with CSDH (p = 0.014). When cephalic index (CI) was divided into the normal and abnormal groups, there was a significant difference between those with IDYS and CSDH (p = 0.000, α = 0.017) and between PD and CSDH (p = 0.031, α = 0.033). The age of onset was significantly correlated with the CI of IDYS (τ = - 0.282, p = 0.016). The Burke-Fahn-Marsden Dystonia Rating Scale motor score (BFMDRS-M) showed a significant correlation with OI in IDYS (τ = 0.372, p = 0.002). The cranial geometry of patients with IDYS was significantly different from that of patients with CSDH. There was a significant correlation between age of onset and CI, as well as between BFMDRS-M and OI, suggesting that short heads in the growth phase and skull balance might be related to the genesis of dystonia and its effect on motor symptoms., (© 2023. The Author(s).)

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.)

Background: Pallidal deep brain stimulation (DBS) effectively alleviates symptoms in dystonia patients, but may induce movement slowness as a side-effect. In Parkinson's disease, hypokinetic symptoms have been associated with increased beta oscillations (13-30 Hz). We hypothesize that this pattern is symptom-specific, thus accompanying DBS-induced slowness in dystonia., Methods: In 6 dystonia patients, pallidal rest recordings with a sensing-enabled DBS device were performed and tapping speed was assessed using marker-less pose estimation over 5 time points following cessation of DBS., Results: After cessation of pallidal stimulation, movement speed increased over time (P < 0.01). A linear mixed-effects model revealed that pallidal beta activity explained 77% of the variance in movement speed across patients (P = 0.01)., Conclusions: The association between beta oscillations and slowness across disease entities provides further evidence for symptom-specific oscillatory patterns in the motor circuit. Our findings might help DBS therapy improvements, as DBS-devices able to adapt to beta oscillations are already commercially available. © 2023 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society., (© 2023 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.)

Deep brain stimulation (DBS) is an established method in the treatment of not only Parkinson's disease motor complications but also dystonia and tremor, and there are data supporting the efficacy of DBS in epilepsy and some psychiatric problems. The alleviation of the neurologic problems may enable females of childbearing age to consider pregnancy because of being able to take care of their child. The aim of the study is to provide a review of the data available on the effect of DBS on the course of pregnancy and delivery in patients suffering from diseases amenable for DBS treatment (Parkinson's disease, dystonia, obsessive compulsive disorder, Tourette's syndrome, epilepsy). Although data available in the literature on pregnancy and childbirth in patients with an implanted active DBS system are limited to small case series and case reports, the number of younger patients implanted with DBS systems will potentially require more attention beyond specialized DBS centers. In emergency deliveries, general obstetricians and neurosurgeons should be provided with a protocol to prevent injuries to the implanted system with potentially devastating consequences for the patient., Competing Interests: None declared., (Thieme. All rights reserved.)

Neural oscillatory activities in basal ganglia have prominent roles in cognitive processes. However, the characteristics of oscillatory activities during cognitive tasks have not been extensively explored in human Globus Pallidus internus (GPi). This study aimed to compare oscillatory characteristics of GPi between dystonia and Parkinson's Disease (PD). A dystonia and a PD patient performed the Intra-Extra-Dimension shift (IED) task during both on and off-medication states. During the IED task, patients had to correctly choose between two visual stimuli containing shapes or lines based on a hidden rule via trial and error. Immediate auditory and visual feedback was provided upon the choice to inform participants if they chose correctly. Bilateral GPi Local Field Potentials (LFP) activity was recorded via externalized DBS leads. Transient high gamma activity (~ 100-150 Hz) was observed immediately after feedback in the dystonia patient. Moreover, these bursts were phase synchronous between left and right GPi with an antiphase clustering of phase differences. In contrast, no synchronous high gamma activity was detected in the PD patient with or without dopamine administration. The off-med PD patient also displayed enhanced low frequency clusters, which were ameliorated by medication. The current study provides a rare report of antiphase homotopic synchrony in human GPi, potentially related to incorporating and processing feedback information. The absence of these activities in off and on-med PD patient indicates the potential presence of impaired medication independent feedback processing circuits. Together, these findings suggest a potential role for GPi's synchronized activity in shaping feedback processing mechanisms required in cognitive tasks., (© 2023. The Author(s).)

Background: Subthalamic nucleus (STN) stimulation is an effective treatment for Parkinson's disease and induced local field potential (LFP) changes that have been linked with clinical improvement. STN stimulation has also been used in dystonia although the internal globus pallidus is the standard target where theta power has been suggested as a physiomarker for adaptive stimulation., Objective: We aimed to explore if enhanced theta power was also present in STN and if stimulation-induced spectral changes that were previously reported for Parkinson's disease would occur in dystonia., Methods: We recorded LFPs from 7 patients (12 hemispheres) with isolated craniocervical dystonia whose electrodes were placed such that inferior, middle, and superior contacts covered STN, zona incerta, and thalamus., Results: We did not observe prominent theta power in STN at rest. STN stimulation induced similar spectral changes in dystonia as in Parkinson's disease, such as broadband power suppression, evoked resonant neural activity (ERNA), finely-tuned gamma oscillations, and an increase in aperiodic exponents in STN-LFPs. Both power suppression and ERNA localize to STN. Based on this, single-pulse STN stimulation elicits evoked neural activities with largest amplitudes in STN, which are relayed to the zona incerta and thalamus with changing characteristics as the distance from STN increases., Conclusions: Our results show that STN stimulation-induced spectral changes are a nondisease-specific response to high-frequency stimulation, which can serve as placement markers for STN. This broadens the scope of STN stimulation and makes it an option for other disorders with excessive oscillatory peaks in STN. © 2022 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society., (© 2022 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.)

Background: Role of radiosurgical lesioning in functional disorders has been restricted because of development of deep brain stimulation (DBS) techniques. However, many elderly patients with comorbidities and coagulation abnormalities may not be eligible for DBS. Radiosurgical lesioning may be a good alternative in such cases. The objective of the study was to review the role of radiosurgical lesioning for functional targets in common functional disorders., Materials and Methods: Literature reports pertaining to common disorders were reviewed. Disorders included are tremors (essential tremors, tremor-dominant Parkinson's disease [PD], multiple sclerosis [MS] related refractory tremors), Parkinson's disease (for rigidity, bradykinesia, drug-induced dyskinesias), dystonia, and obsessive-compulsive disorder (OCD)., Results: The most commonly performed procedure was ventral intermediate nucleus (VIM) lesioning for essential tremors and tremor-dominant PD, with about 90% patients demonstrating improvement. Intractable OCD with 60% responders is a promising indication. Other disorders are less commonly treated, with dystonia being the least commonly treated entity. Subthalamic nucleus (STN) and globus pallidus interna/posteroventral pallidum (GPi) lesioning are very rarely reported, and the available literature suggests caution due to high rates of adverse effects., Conclusions: Outcomes for radiosurgical lesioning for essential tremors (VIM) and OCD (anterior limb of internal capsule [ALIC]) are encouraging. Radiosurgical lesioning offers a lower immediate risk profile in patient population with several comorbidities; however, long-term adverse effects due to radiation are a concern, especially for STN and GPi lesioning.

The contemporary technique of deep brain stimulation (DBS) is very effective for management of movement disorders-including Parkinson's disease, generalized dystonia, and tremors-and has also been successfully applied for novel indications (e.g., intractable epilepsy and chronic pain). As a result, growing numbers of DBS procedures have been performed worldwide; correspondingly, the incidence of associated morbidity has also increased. All complications of DBS can be divided into those associated with (1) the surgical procedure, (2) the device itself, and (3) the applied electrical stimulation. On the basis of an analysis of the available literature and the personal experience of the author, it may be concluded that implantation of a DBS device is a relatively safe procedure accompanied by very low risks of major morbidity or a permanent neurological deficit. Nevertheless, awareness of the possible complications and application of appropriate preventive measures for their avoidance are very important for providing safe and effective treatment., (© 2023. Springer Nature Switzerland AG.)

Purpose of Review: Deep brain stimulation (DBS) is an established treatment in several movement disorders, including Parkinson's disease, dystonia, tremor, and Tourette syndrome. In this review, we will review and discuss the most recent findings including but not limited to clinical evidence., Recent Findings: New DBS technologies include novel hardware design (electrodes, cables, implanted pulse generators) enabling new stimulation patterns and adaptive DBS which delivers potential stimulation tailored to moment-to-moment changes in the patient's condition. Better understanding of movement disorders pathophysiology and functional anatomy has been pivotal for studying the effects of DBS on the mesencephalic locomotor region, the nucleus basalis of Meynert, the substantia nigra, and the spinal cord. Eventually, neurosurgical practice has improved with more accurate target visualization or combined targeting. A rising research domain emphasizes bridging neuromodulation and neuroprotection. Recent advances in DBS therapy bring more possibilities to effectively treat people with movement disorders. Future research would focus on improving adaptive DBS, leading more clinical trials on novel targets, and exploring neuromodulation effects on neuroprotection., (© 2022. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Sex and gender-based differences in epidemiology, clinical features and therapeutical responses are emerging in several movement disorders, even though they are still not widely recognized. In this chapter, we summarize the most relevant evidence concerning these differences in Parkinson's disease, essential tremor, dystonia and chorea. Indeed, both sex-related biological (hormonal levels fluctuations) and gender-related variables (socio-cultural and environmental factors) may differently impact symptoms manifestation and severity, phenotype and disease progression of movement disorders on men and women. Moreover, sex differences in treatment responses should be taken into account in any therapeutical planning. Physicians need to be aware of these major differences between men and women that will eventually have a major impact on better tailoring prevention, treatment, or even delaying progression of the most common movement disorders., (Copyright © 2022 Elsevier Inc. All rights reserved.)

Intraoperative neurophysiological information could increase accuracy of surgical deep brain stimulation (DBS) lead placement. Subsequently, DBS therapy could be optimized by specifically targeting pathological activity. In Parkinson's disease, local field potentials (LFPs) excessively synchronized in the beta band (13-35 Hz) correlate with akinetic-rigid symptoms and their response to DBS therapy, particularly low beta band suppression (13-20 Hz) and high frequency gamma facilitation (35-250 Hz). In dystonia, LFPs abnormally synchronize in the theta/alpha (4-13 Hz), beta and gamma (60-90 Hz) bands. Phasic dystonic symptoms and their response to DBS correlate with changes in theta/alpha synchronization. In essential tremor, LFPs excessively synchronize in the theta/alpha and beta bands. Adaptive DBS systems will individualize pathological characteristics of neurophysiological signals to automatically deliver therapeutic DBS pulses of specific spatial and temporal parameters.

Stereotactic and functional neurosurgery(deep brain stimulation[DBS]and radiofrequency coagulation)is an established method of treatment for patients with Parkinson's disease, tremor, and/or dystonia. The surgery involves many pitfalls and is similar to other surgeries, requiring experience and skills. Here, we have discussed three categories of DBS-related complications, including surgical procedure-related and device-related complications, and stimulation-induced side effects. In addition, we have discussed the prevention and coping methods, including those not listed in the guidelines for stereotactic and functional neurosurgery.

Deep brain stimulation(DBS)is an effective therapy for conditions involving drug-resistant involuntary movements, such as Parkinson's disease, tremor, and dystonia. Programming of DBS, as well as strict surgical indications, appropriate target selection, and accurate electrode placement, is one of the most important factors in the success of DBS. To obtain effective stimulation for a long period, it is important to expand the therapeutic window and reduce side effects. Recent advances in DBS devices have dramatically expanded the variety of stimulus settings. While the indication criteria of DBS and surgical techniques have been established, the details of the programming algorithm are not yet unified. In this paper, we describe the features of each device, basic programming methods, management of DBS-related side effects, and advanced stimulus methods.

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.)

Deep brain stimulation (DBS) depends on precise delivery of electrical current to target tissues. However, the specific brain structures responsible for best outcome are still debated. We applied probabilistic stimulation mapping to a retrospective, multidisorder DBS dataset assembled over 15 years at our institution (n total = 482 patients; n Parkinson disease = 303; n dystonia = 64; n tremor = 39; n treatment-resistant depression/anorexia nervosa = 76) to identify the neuroanatomical substrates of optimal clinical response. Using high-resolution structural magnetic resonance imaging and activation volume modeling, probabilistic stimulation maps (PSMs) that delineated areas of above-mean and below-mean response for each patient cohort were generated and defined in terms of their relationships with surrounding anatomical structures. Our results show that overlap between PSMs and individual patients' activation volumes can serve as a guide to predict clinical outcomes, but that this is not the sole determinant of response. In the future, individualized models that incorporate advancements in mapping techniques with patient-specific clinical variables will likely contribute to the optimization of DBS target selection and improved outcomes for patients. ANN NEUROL 2021;89:426-443., (© 2020 American Neurological Association.)

Purpose: Deep brain stimulation (DBS) is being increasingly utilized to treat movement disorders including Parkinson's disease (PD), essential tremor (ET), and dystonia. An improved understanding of national trends in safety and cost is necessary. Herein, our objectives are to (1) characterize complication, mortality, and cost profiles of patients undergoing DBS for movement disorders in the United States, (2) identify predictors of morbidity and mortality, and (3) evaluate impact of complications on cost., Methods: DBS surgeries were extracted from the National Inpatient Sample (NIS) 2002-2014 for the clinical indications of PD, ET, and dystonia. Patient characteristics and eight complication categories (hardware malfunction, infection, neurological, other haemorrhagic, thromboembolic, cardiac, pulmonary, and renal/urinary) were reviewed. Outcomes included complications, mortality, hospitalization length, and inflation-adjusted cost., Results: There were 44,866 weighted admissions (PD-73.5%, ET-22.7%, dystonia-3.8%). The number of procedures increased 2.22-fold from 2002 to 2014 ( N  = 2372 in 2002; N  = 5260 in 2014). Inpatient cost was $22,802 ± 13,164, remaining stable from 2002 to 2014 ($24,188 ± 15,910, $20,630 ± 11,031, respectively). Four percent experienced complications (dystonia-6.0%, PD-4.4%, ET-3.1%, p  < .001). In-hospital mortality was 0.2%. Cost was greater in patients with complications ($36,306 ± 29,263 vs. $22,196 ± 11,560, p  < .001). Most common complications were renal/urinary (1.5%), neurological (1.1%), and pulmonary (0.7%). Thromboembolic, pulmonary, and haemorrhagic complications were associated with greatest cost., Conclusion: Increased DBS utilization for adult movement disorders in the United States from 2002 to 2014 was attributed to rapid adoption by teaching hospitals for PD. DBS remains a safe procedure with low overall complications and stable inpatient costs from 2002 to 2014. Complication risks vary by type of movement disorder, and although rare, multiple complications increase morbidity and cost of care.

Introduction: Deep brain stimulation (DBS) therapy for Parkinson's Disease (PD) and dystonia is associated with the possibility of both minor and major complications. One possible side effect is the depletion of implantable pulse generator (IPG) battery and the associated sudden recurrence of PD or dystonia symptoms, which can be potentially life-threatening. Delayed or postponed outpatient visits due to COVID -19 may be a risk factor of battery end-of-life consequences., Objective: To analyse the clinical outcomes in reported PD and dystonia patients treated with DBS, who, as a result of the sudden depletion of the neurostimulator battery, developed life-threatening symptoms., Materials and Methods: The databases of PubMed, Scopus, EMBASE and Google Scholar were searched using pre-established criteria., Results: A total of 244 articles was found, of which 12 met the adopted criteria. Selected papers presented a total of 17 case reports of DBS-treated patients - 11 with PD, and six with dystonia - who had depleted IPG batteries and due to rapid worsening of PD/dystonia symptoms required urgent hospital admission. IPG battery replacement was the only effective treatment in the majority of cases., Conclusions: IPG battery depletion can result in fatal outcomes. Sudden recurrence of PD or dystonia symptoms in patients treated by DBS can be potentially life-threatening, so scheduling the replacement of a discharged IPG battery should not be postponed. The COVID-19 pandemic should alert staff at emergency, neurology and movement disorders wards not to postpone the visits of patients with an implanted DBS system.

Neuromodulation involves altering neuronal circuitry and subsequent physiological changes with the aim to ameliorate neurological symptoms. Over the years several techniques have been used to obtain neuromodulatory effects for treatment of conditions including Parkinson disease, essential tremor, dystonia or seizures. We provide brief description of the various therapeutics that have been used and mechanisms involved in pathophysiology of these disorders as well as the therapeutic mechanisms of the treatment modalities., Competing Interests: None

In people with young onset Parkinson's disease (YOPD), onset of symptoms is between 21 and 40 years of age. The distinction between YOPD and late-onset Parkinson's disease is supported by genetic differences (a genetic etiology is more common in people with YOPD) and clinical differences (e.g., dystonia and levodopa-induced dyskinesias are more common inYOPD). Moreover, people with YOPD tend to have different family and societal engagements compared to those with late-onset PD. These unique features have implications for clinical management, and call for a tailored multidisplinary approach involving shared-decision making.

Dystonia and Parkinson's disease are closely linked disorders sharing many pathophysiological overlaps. Dystonia can be seen in 30% or more of the patients suffering with PD and sometimes can precede the overt parkinsonism. The response of early dystonia to the introduction of dopamine replacement therapy (levodopa, dopamine agonists) is variable; dystonia commonly occurs in PD patients following levodopa initiation. Similarly, parkinsonism is commonly seen in patients with mutations in various DYT genes including those involved in the dopamine synthesis pathway. Pharmacological blockade of dopamine receptors can cause both tardive dystonia and parkinsonism and these movement disorders syndromes can occur in many other neurodegenerative, genetic, toxic and metabolic diseases. Pallidotomy in the past and currently deep brain stimulation largely involving the GPi are effective treatment options for both dystonia and parkinsonism. However, the physiological mechanisms underlying the response of these two different movement disorder syndromes are poorly understood. Interestingly, DBS for PD can cause dystonia such as blepharospasm and bilateral pallidal DBS for dystonia can result in features of parkinsonism. Advances in our understanding of these responses may provide better explanations for the relationship between dystonia and Parkinson's disease., (Copyright © 2019 Elsevier Inc. All rights reserved.)

Background: Deep brain stimulation (DBS) is a treatment modality increasingly utilized in the management of neurological and psychiatric conditions. Neurosurgical technical considerations and contraindications have yet to be thoroughly characterized in the literature. The patient population for DBS includes many elderly patients with multiple comorbidities who require treatments and investigations that expose them to electromagnetic fields of varying strengths and durations, including other implanted electromodulatory devices., Objective: To determine if clinically significant interference arises between DBS and cardiac pacemaker systems., Methods: Here we audited 8 patients, mean age 72, with cardiac pacemakers and DBS implanted from 2007 to 2015. We investigated details of their neurological and electrocardiological treatment and progress and sought evidence for interference between the two systems., Results: We found no evidence of DBS dysfunction, and only one case of abnormal pacemaker interrogation 2 yr post-DBS implantation was found, which was thought to be secondary to a medication issue rather than neuromodulation interference., Conclusion: Our research reassures the clinician that pacemakers and DBS systems do not appear to affect one another and provides guidance on minimizing possibility of this., (Copyright © 2019 by the Congress of Neurological Surgeons.)

Guidelines recommend Botulinum toxin-A (BoNT-A) after deep brain stimulation (DBS), although the effectiveness of their combined use is uncertain. A chart review of Parkinson's disease (17) and dystonia (7) patients undergoing 302 injections with IncobotulinumtoxinA before or after DBS was performed. Patients with cervical dystonia received less IncobotulinumtoxinA after DBS (290.7 ± 124.0 vs. 192.4 ± 131.4, p = 0.005) and experienced an increased benefit (4.0 ± 3.4 vs. 8.4 ± 3.6 weeks, p = 0.003). No significant differences were found when comparing the treatment outcomes of 14 patients who received both IncobotulinumtoxinA and OnabotulinumtoxinA after DBS. The use of BoNT-A after DBS is a useful strategy although prospective studies are needed.

Background: A large number of methods have been described that use transcranial magnetic stimulation to probe the physiology of the human motor cortex. Since the 1990s, hundreds of papers have used them to investigate neurophysiological signatures of different types of movement disorders. However, in recent years there has been increasing recognition of the interindividual variability of these measures and a focus on estimating their reliability and reproducibility. Although this work has been carried out in healthy individuals, it is highly relevant to movement disorders because it may impact the validity of some accepted ("canonical") neurophysiological biomarkers. The aim of this review is to reexamine the diagnostic usefulness of transcranial magnetic stimulation methods in movement disorders in the context of present knowledge of methodological variability., Methods: We conducted a search of the PubMed database for research and review articles on transcranial magnetic stimulation and its diagnostic utility in movement disorders (specifically Parkinson's disease and atypical parkinsonism, dystonia, Tourette syndrome and other chronic tic disorders, Huntington's disease, and essential tremor). We highlighted contradictions in the literature and common misconceptions with the aim of providing a clearer picture of the reliability of these measures in differential diagnosis of movement disorders., Conclusion: Although there is no doubt that these studies have provided useful insight into the pathophysiology of movement disorders, there is a clear disagreement among many studies that questions the validity of some of the so called "canonical" findings as diagnostic markers. However, useful findings remain and even those with higher variability can be used to support clinical diagnosis in selected cases. © 2019 International Parkinson and Movement Disorder Society., (© 2019 International Parkinson and Movement Disorder Society.)

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.)

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.)

In Parkinson's disease (PD), subthalamic nucleus beta band oscillations are decreased by therapeutic deep-brain stimulation (DBS) and this has been proposed as important to the mechanism of therapy. The globus pallidus is a common alternative target for PD with similar motor benefits as subthalamic DBS, but effects of pallidal stimulation in PD are not well studied, and effects of pallidal DBS on cortical function in PD are unknown. Here, in 20 PD and 14 isolated dystonia human patients of both genders undergoing pallidal DBS lead implantation, we recorded local field potentials from the globus pallidus and in a subset of these, recorded simultaneous sensorimotor cortex ECoG potentials. PD patients had elevated resting pallidal low beta band (13-20 Hz) power compared with dystonia patients, whereas dystonia patients had elevated resting pallidal theta band (4-8 Hz) power compared with PD. We show that this results in disease-specific patterns of interaction between the pallidum and motor cortex: PD patients demonstrated relatively elevated phase coherence with the motor cortex in the beta band and this was reduced by therapeutic pallidal DBS. Dystonia patients had greater theta band phase coherence. Our results support the hypothesis that specific motor phenomenology observed in movement disorders are associated with elevated network oscillations in specific frequency bands, and that DBS in movement disorders acts in general by disrupting elevated synchronization between basal ganglia output and motor cortex. SIGNIFICANCE STATEMENT Perturbations in synchronized oscillatory activity in brain networks are increasingly recognized as important features in movement disorders. The globus pallidus is a commonly used target for deep-brain stimulation (DBS) in Parkinson's disease (PD), however, the effects of pallidal DBS on basal ganglia and cortical oscillations are unknown. Using invasive intraoperative recordings in patients with PD and isolated dystonia, we found disease-specific patterns of elevated oscillatory synchronization within the pallidum and in coherence between pallidum and motor cortex. Therapeutic pallidal DBS in PD suppresses these elevated synchronizations, reducing the influence of diseased basal ganglia on cortical physiology. We propose a general mechanism for DBS therapy in movement disorders: functional disconnection of basal ganglia output and motor cortex by coherence suppression., (Copyright © 2018 the authors 0270-6474/18/384556-13$15.00/0.)

Deep brain stimulation (DBS) has emerged as a revolutionary treatment option for essential tremor (ET), Parkinson's disease (PD), idiopathic dystonia, and severe obsessive-compulsive disorder (OCD). This article reviews the historical foundations of DBS including basal ganglia pathophysiological models, classic principles of electrical stimulation, technical components of the DBS system, treatment risks, and future directions for DBS. Chronic high frequency stimulation induces a number of functional changes from fast physiological to slower metabolic effects and ultimately leads to structural reorganization of the brain, so-called neuroplasticity. Examples of each of these fast, slow, and long-term changes are given in the context of Parkinson's disease where these mechanisms have perhaps been the most intensely investigated. In particular, details of striatal dopamine release, expression of trophic factors, and a possible neuroprotective mechanism of DBS are highlighted. We close with a brief discussion of technical and clinical considerations for improvement. Deep brain stimulation will continue to offer a reversible and safe therapeutic option for a host of neurological conditions and remains one of the best windows into human brain physiology.

Objective: To report on the long-term outcomes of deep brain stimulation (DBS) of the thalamic ventral intermediate nucleus (VIM) in Parkinson disease (PD), essential tremor (ET), and dystonic tremor., Methods: One hundred fifty-nine patients with PD, ET, and dystonia underwent VIM DBS due to refractory tremor at the Grenoble University Hospital. The primary outcome was a change in the tremor scores at 1 year after surgery and at the latest follow-up (21 years). Secondary outcomes included the relationship between tremor score reduction over time and the active contact position. Tremor scores (Unified Parkinson's Disease Rating Scale-III, items 20 and 21; Fahn, Tolosa, Marin Tremor Rating Scale) and the coordinates of the active contacts were recorded., Results: Ninety-eight patients were included. Patients with PD and ET had sustained improvement in tremor with VIM stimulation (mean improvement, 70% and 66% at 1 year; 63% and 48% beyond 10 years, respectively; p < 0.05). There was no significant loss of stimulation benefit over time ( p > 0.05). Patients with dystonia exhibited a moderate response at 1-year follow-up (41% tremor improvement, p = 0.027), which was not sustained after 5 years (30% improvement, p = 0.109). The more dorsal active contacts' coordinates in the right lead were related to a better outcome 1 year after surgery ( p = 0.029). During the whole follow-up, forty-eight patients (49%) experienced minor side effects, whereas 2 (2.0%) had serious events (brain hemorrhage and infection)., Conclusions: VIM DBS is an effective long-term (beyond 10 years) treatment for tremor in PD and ET. Effects on dystonic tremor were modest and transient., Classification of Evidence: This provides Class IV evidence. It is an observational study., (© 2017 American Academy of Neurology.)

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.)

Dystonia is a hyperkinetic movement disorder that can be highly stigmatizing and disabling. Substantial evidence from animal models, neuropathological, neurophysiological, neuroimaging and clinical studies emphasizes the role of dopaminergic dysfunction in the pathophysiology of dystonia, illustrating possible pathophysiological overlap with parkinsonism. Furthermore, basal ganglia dysfunction has been implicated in the pathogenesis of dystonia, and is well established to underlie the manifestations of Parkinson's disease. Clinically, parkinsonian features are a key characteristic of some combined dystonias, including dopa-responsive dystonia, and Parkinson's disease often presents with dystonia. Moreover, many treatments effective in Parkinson's disease, both medical and surgical, also offer some benefit in dystonia. Therefore, mild parkinsonian features might logically accompany idiopathic and inherited isolated dystonias. However, as the current literature is particularly scant, the present review aimed to investigate mild parkinsonism in idiopathic and inherited dystonia. We found limited evidence alluding to the presence of mildly reduced arm-swing, increased tone, and non-decremental bradykinesia in adult-onset focal dystonia. Tremor, with postures, action and rest, also occurs commonly in idiopathic isolated dystonia, and can simulate Parkinson's disease tremor and be a cause of 'scans without evidence of dopaminergic deficit'. Parkinsonian features in monogenic isolated dystonias have been less well investigated, despite the potential benefit of correlating pathophysiological and clinical findings. The recognition and improved clinical characterization of parkinsonian features in idiopathic and inherited isolated dystonia extends the clinical spectrum of motor features in dystonia, which may help avoid incorrect diagnosis and inform therapeutic research., (Copyright © 2016 Elsevier Ltd. All rights reserved.)

Objective To explore the efficacy of target positioning by preoperative CT/MRI image fusion technique in deep brain stimulation.Methods We retrospectively analyzed the clinical data and images of 79 cases (68 with Parkinson's disease, 11 with dystonia) who received preoperative CT/MRI image fusion in target positioning of subthalamic nucleus in deep brain stimulation. Deviation of implanted electrodes from the target nucleus of each patient were measured. Neurological evaluations of each patient before and after the treatment were performed and compared. Complications of the positioning and treatment were recorded.Results The mean deviations of the electrodes implanted on X, Y, and Z axis were 0.5 mm, 0.6 mm, and 0.6 mm, respectively. Postoperative neurologic evaluations scores of unified Parkinson's disease rating scale (UPDRS) for Parkinson's disease and Burke-Fahn-Marsden Dystonia Rating Scale (BFMDRS) for dystonia patients improved significantly compared to the preoperative scores (P<0.001); Complications occurred in 10.1% (8/79) patients, and main side effects were dysarthria and diplopia.Conclusion Target positioning by preoperative CT/MRI image fusion technique in deep brain stimulation has high accuracy and good clinical outcomes.

Circuitry models of Parkinson's disease (PD) are based on striatal dopamine loss and aberrant striatal inputs into the basal ganglia network. However, extrastriatal mechanisms have increasingly been the focus of attention, whereas the status of striatal discharges in the parkinsonian human brain remains conjectural. We now report the activity pattern of striatal projection neurons (SPNs) in patients with PD undergoing deep brain stimulation surgery, compared with patients with essential tremor (ET) and isolated dystonia (ID). The SPN activity in ET was very low (2.1 ± 0.1 Hz) and reminiscent of that found in normal animals. In contrast, SPNs in PD fired at much higher frequency (30.2 ± 1.2 Hz) and with abundant spike bursts. The difference between PD and ET was reproduced between 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine-treated and normal nonhuman primates. The SPN activity was also increased in ID, but to a lower level compared with the hyperactivity observed in PD. These results provide direct evidence that the striatum contributes significantly altered signals to the network in patients with PD., Competing Interests: The authors declare no conflict of interest.

In this review, the available evidence to guide clinicians regarding eligibility for deep brain stimulation (DBS) in the main conditions in which these forms of therapy are generally indicated-Parkinson's disease (PD), tremor, and dystonia-is presented. In general, the literature shows that DBS is effective for PD, essential tremor, and idiopathic dystonia. In these cases, key points in patient selection must include the level of disability and inability to manage symptoms using the best available medical therapy. Results are, however, still not optimal when dealing with other aetiologies, such as secondary tremors and symptomatic dystonia. Also, in PD, issues such as age and neuropsychiatric profile are still debatable parameters. Overall, currently available literature is able to guide physicians on basic aspects of patient selection and indications for DBS; however, a few points are still debatable and controversial. These issues should be refined and clarified in future studies.

Deep brain stimulation (DBS) has been an established surgical treatment option for dyskinesia from Parkinson disease and for dystonia. The present article deals with the timing of surgical intervention, selecting an appropriate target, and minimizing adverse effects. We provide an overview of current evidences and issues for dyskinesia and dystonia as well as emerging DBS technology.

Deep brain stimulation (DBS) of the subthalamic nucleus (STN) orglobus pallidus pars interna (GPi) is well established as a treatment for advanced Parkinson's disease. In general, one of the 2 targets is chosen based on the clinical features of each patient. Stimulation of both targets could be viewed as redundant, given that the 2 targets are directly connected. However, it is possible that each target has different mechanisms, with clinical effects mediated by orthodromic or antidromic stimulation. The authors report the case of a patient with severe Parkinson's disease who had previously undergone bilateral subthalamic stimulation with excellent benefits. However, he presented with significant worsening associated with disease progression and pharmacological treatment, and then underwent bilateral GPi DBS. Follow-up assessment was conducted clinically as well as through blinded ratings of video recordings. Pallidal DBS may be a safe and useful strategy to manage dystonic features and behavioral complications of subthalamic stimulation and pharmacological management. While combined stimulation was quite successful in the reported patient, further studies with larger samples and longer follow-up periods will be necessary before recommending the addition of pallidal DBS as a routine strategy for patients previously implanted with STN DBS.