The Motor Network in Essential Tremor: Mechanisms of Therapy
Essential TremorParkinson's DiseaseEssential tremor (ET) is among the most common movement disorders, and is the most prevalent tremor disorder. It is a progressive, degenerative brain disorder that results in increasingly debilitating tremor, and afflicts an estimated 7 million people in the US (2.2% of the population) and estimates from population studies worldwide range from 0.4% to 6.3%. ET is directly linked to progressive functional impairment, social embarrassment, and even depression. Intention (kinetic) tremor of the arms occurs in approximately half of ET patients, and is typically a slow tremor (~5-10Hz) that occurs at the end of a purposeful movement, and is insidiously progressive over many years. Based on direct and indirect neurophysiological studies, it has been suggested that a pathological synchronous oscillation in a neuronal network involving the ventral intermediate nucleus (Vim) of the thalamus, the premotor (PM), primary motor (M1) cortices, and the cerebellum, may result in the production of ET. In spite of the numerous therapeutic modalities available, 65% of those suffering from upper limb tremor report serious difficulties during their daily lives. Deep brain stimulation (DBS) has emerged as an effective treatment option for those suffering from medically refractory ET. The accepted target for ET DBS therapy is the Vim thalamus. Vim projects to PM, M1, and supplementary motor areas (SMA) and receives afferents from the ipsilateral cerebellum. Moreover, electrophysiological recordings from Vim during stereotactic surgery have identified "tremor cells" that synchronously discharge with oscillatory muscle activity during tremor. Clinical and computational findings indicate that DBS suppresses tremor by masking these "burst driver" inputs to the thalamus. The overall goal is to investigate the neural signatures of tremor generation in the thalamocortical network by recording data during DBS implantation surgery. Investigators will record data from the macroelectrode implanted in the Vim for DBS therapy, and through an additional 6-contact subdural cortical strip that will be placed on the hand motor cortical area temporarily through the same burr hole opened for the implantation of the DBS electrode.
The STEREO-DBS ET Study: 7-Tesla MRI Brain Network Analysis for Deep Brain Stimulation in Essential...
Essential TremorRationale: Deep brain stimulation (DBS) of the thalamus is an effective surgical treatment for the patients with advanced essential tremor, despite optimal pharmacological treatment. However, individual improvement after DBS remains variable and 20% of patients experience side effects. To date, DBS-electrode placement and settings in the highly connected thalamus are based on 1,5-Tesla or 3-Tesla MR-images. These low resolution and solely structural modalities are unable to visualize the multiple brain networks to this small nucleus and prevent electrode activation directed at its cortical projections. By using structural 7-Tesla MRI (7T MRI) connectivity to visualize (malfunctioning) brain networks, DBS-electrode placement and activation can be individualized. Objective: Primary objective of the study is to determine whether visualisation of cortical projections originating in the thalamus and the position of the DBS electrode relative to these projections using 7T MRI improves tremor as measured by the clinically validated Essential Tremor Rating Assessment Scale after six months of DBS. Secondary outcomes are: disease related daily functioning, adverse effects, operation time, quality of life, patient satisfaction with treatment outcome and patient evaluation of treatment burden. Study design: The study will be a single center prospective observational study. Study population: Enrollment will be ongoing from June 2023. Intervention (if applicable): No intervention will be applied. Application of 7T MRI for DBS is standard care and outcome scores used will be readily accessible from the already existing advanced electronic DBS database. Main study parameters/endpoints: The primary outcome measure is the change in motor symptoms as measured by the disease-specific Essential Tremor Rating Assessment Scale (TETRAS). This is measured after 6 months of DBS as part of standard care. The secondary outcome measures are the Amsterdam Linear Disability Score for functional health status, Quality of Life in Essential Tremor Questionnaire, patient satisfaction with the treatment, patient evaluation of treatment burden, operating time, hospitalization time, change of tremor medication, side effects and complications. Nature and extent of the burden and risks associated with participation, benefit and group relatedness: The proposed observational research project involves treatment options that are standard care in daily practice. The therapies will not be combined with other research products. Participation in this study constitutes negligible risk according to NFU criteria for human research.
Cortical-Basal Ganglia Speech Networks
Parkinson DiseaseEssential Tremor1 moreIn this research study the researchers want to learn more about brain activity related to speech perception and production.
Chinese ET Registry (CETR)
Essential TremorThe purpose of the Chinese Essential Tremor Registry (CETR) is to develop a database of patients with Essential tremor in China.
Echo-Focusing in Patients With Treatment-Resistant Neurologic and Psychiatric Indications (EF001)...
Essential TremorNeurologyEvaluate the safety and effectiveness of Echo-Focusing using Exablate Neuro as a tool for treating patients with treatment-refractory neurologic and psychiatric disorders.
Imaging Study of Tremor Disorders
Movement DisordersTo explore the pathogenesis underlying tremor in essential tremor (ET) and parkinson disease (PD) as well as the mechanisms of tremor suppression after Magnetic resonance-guided focused ultrasound (MRgFUS) thalamotomy through multi-model MRI study, and to identify imaging biomarkers for triaging patients for the suitability of MRgFUS thalamotomy and predicting the treatment effectiveness. Essential tremor (ET) and Parkinson disease (PD) are the most prevalent tremor disorders. ET, considered as a pure tremor disease, is characterized by upper limb intention or postural tremor, while PD is characterized by a variety of motor and nonmotor symptoms, among them rest tremor. A number of studies have demonstrated that Magnetic resonance-guided focused ultrasound (MRgFUS) thalamotomy is a minimally invasive and effective procedure suitable for medication-refractory tremor in patients with ET and patients with PD. However, the treatment effectiveness is variable among individuals. Therefore, it is important to clarify the pathogenesis of tremor in both ET and PD and the mechanisms of tremor arrest produced by MRgFUS thalamotomy to triage suitable candidates for MRgFUS thalamotomy and predict clinical outcomes. In addition, localization precision and individualized treatment remain to be improved.
Comparison of the Electric Plasma Surgical Tool "PlasmaBlade" for Replacement of the Deep Brain...
Parkinson DiseaseEssential Tremor2 moreThe deep brain stimulation is surgical technique used for the Parkinson's disease, essential tremor, dystonia, epilepsy, and psychiatric diseases. A pulse generator or battery (implanted pulse generator, IPG) is a need for replacement every few years. In general, electric cautery(BOVIE), which is commonly used in surgery, cannot be used when the deep brain stimulation machine is inserted, so conventional tools such as scissors and knives are used for replacement surgery. However, in the process, damage to the machine may be inflicted by knives, scissors, etc., and in the worst case, the machine may be unusable, resulting in financial and human consumption. Plasma Blade is currently used for tissue incision and coagulation in Korea, and is the only insurance-recognized tool in Korea for the replacement surgery of a cardiovascular implantable electronic device (CIED). The deep brain stimulation machine has a structure very similar to that of the heart electronics. In addition, the plasma blade was used to replace the deep brain stimulation machine overseas.The safety is reported in the surgery, so the plasma blade deep brain stimulation machine has been replaced in Korea. The investigators would like to check the safety and effectiveness for use in surgery.
Neurofeedback Using Implanted Deep Brain Stimulation Electrodes
Parkinson DiseaseEpilepsy1 moreDeep brain stimulation (DBS) has become a gold-standard symptomatic treatment option for Parkinson's disease (PD) and is also explored for a variety of other neurological disorders. The implantation of electrodes into deep brain areas has not only enabled the application of electrical stimuli, but has also provided researchers and clinicians with an unprecedented window to investigate aberrant neuronal activity right at the core of pathological brain circuits. Local field potentials (LFP) have already been readily investigated through externalised DBS electrode wires prior to internalisation and connection to an implantable neurostimulator. In the case of PD, motor symptoms have been evidenced to correlate with exaggerated beta oscillatory activity (13-35 Hz) in the LFP recorded from the subthalamic nucleus (STN). Firstly, beta activity recorded in the STN at rest in patients withdrawn from their medication has been correlated with the Unified Parkinson's Disease Rating Scale (UPDRS) across patients. Secondly, a reduction of signal power in the beta-band was correlated with clinical improvements of motor symptoms. Thirdly, the two main therapeutic strategies, the administration of L-Dopa, and high-frequency DBS both lead to a suppression of beta-synchronicity in the STN. Furthermore, beta-oscillations show fast and movement-dependent modulation over time and can serve as a biomarker and feedback signal to control the delivery of DBS. The investigators recently implemented deep brain electrical neurofeedback to provide real-time visual neurofeedback of pathological STN oscillations through externalised DBS electrodes and showed that PD patients were able to volitionally control and reduce subthalamic activity within a single 1 hour session. Moreover, neurofeedback-learnt strategies accelerated movements and could be retained in the short- and mid-term. Only recently, a newly developed neurostimulator, the Percept™ PC (Medtronic Neurological Division, Minneapolis, MN, USA), has been clinically approved, which can not only apply electrical impulses, but also enable the measurement and transmission of brain activity. This neurostimulator is now the first choice for implantations at the University Hospital Zurich and is used for a variety of neurological disorders. The investigators' goal is to investigate whether neurofeedback through a fully implanted deep brain stimulation device is possible and can lead to a better control of pathological oscillations as well as symptom mitigation. Having shown that endogenous control over deep brain oscillations is possible, the investigators will also test this novel therapeutic approach for pathologies other than PD that are also treated with DBS. Neurofeedback using implanted DBS electrodes will have the advantage of enabling longer and multiple-day training sessions, which the investigators hypothesise to have a larger impact on control over pathological deep brain oscillations and neurological symptoms, as such a fully implanted neurofeedback system no longer requires the externalisation of DBS wires and is as such no longer limited to the first two days after electrode implantation. All in all, the investigators will not exceed a total streaming time of 7 hours per patients (7 d of battery time), which the investigators deem justifiable with respect to a battery life of > 5 years. This proposed research is highly significant as it will help our understanding of various neurological diseases that are highly prevalent in society (PD being, for instance, the second most common neurodegenerative disorder after Alzheimer's disease) and might culminate in novel, endogenous treatment strategies. The overall risk for patients is minimal to non-existent, as stimulation parameters are unaffected and the intended changes in brain activity are self-induced while DBS stimulation is off.
Abbott DBS Post-Market Study of Outcomes for Indications Over Time
Movement DisordersParkinson Disease5 moreThe purpose of this international study is to evaluate long-term safety and effectiveness of Abbott deep brain stimulation (DBS) systems for all indications, including Parkinson's disease, essential tremor or other disabling tremor and dystonia.
Brain Networks and Consciousness
Loss of ConsciousnessParkinson Disease2 moreGeneral anesthesia (GA) is a medically induced state of unresponsiveness and unconsciousness, which millions of people experience every year. Despite its ubiquity, a clear and consistent picture of the brain circuits mediating consciousness and responsiveness has not emerged. Studies to date are limited by lack of direct recordings in human brain during medically induced anesthesia. Our overall hypothesis is that the current model of consciousness, originally proposed to model disorders and recovery of consciousness after brain injury, can be generalized to understand mechanisms of consciousness more broadly. This will be studied through three specific aims. The first is to evaluate the difference in anesthesia sensitivity in patients with and without underlying basal ganglia pathology. Second is to correlate changes in brain circuitry with induction and emergence from anesthesia. The third aim is to evaluate the effects of targeted deep brain stimulation on anesthesia induced loss and recovery of consciousness. This study focuses on experimentally studying these related brain circuits by taking advantage of pathological differences in movement disorder patient populations undergoing deep brain stimulation (DBS) surgery. DBS is a neurosurgical procedure that is used as treatment for movement disorders, such as Parkinson's disease and essential tremor, and provides a mechanism to acquire brain activity recordings in subcortical structures. This study will provide important insight by using human data to shed light on the generalizability of the current model of consciousness. The subject's surgery for DBS will be prolonged by up to 40 minutes in order to record the participant's brain activity and their responses to verbal and auditory stimuli.