Essential Tremor Research Articles

The Clinical Utility of Botulinum Toxin in the Field of Otolaryngology

Botulinum toxin, originally identified in relation to botulism, has evolved from being considered a perilous pathogen to an invaluable therapeutic agent. First utilized by Alan Scott in 1977 to treat strabismus under the commercial name, Oculinum, the toxin received Food and Drug Administration approval in 1989 and was subsequently rebranded as Botox. Its clinical applications have expanded notably, especially in the field of otolaryngology, proving effective in managing conditions such as spasmodic dysphonia, essential vocal tremor, and chronic salivary gland disorders. Moreover, botulinum toxin has shown promising results in treating persistent chronic rhinitis, objective tinnitus, and synkinesis following facial palsy, significantly improving involuntary facial movements. This paper details the diverse applications and methodologies of botulinum toxin across various ENT disorders, illustrating its growing scope and significance in medical practice.

An Algorithm for Automated Measurement of Kinetic Tremor Magnitude Using Digital Spiral Drawings

Introduction: Essential tremor is a common movement disorder. Numerous validated clinical rating scales exist to quantify essential tremor severity by employing rater-dependent visual observation but have limitations, including the need for trained human raters and the lack of precision and sensitivity compared to technology-based objective measures. Other continuous objective methods to quantify tremor amplitude have been developed, but frequently provide unitless measures (e.g., tremor power), limiting real-world interpretability. We propose a novel algorithm to measure kinetic tremor amplitude using digital spiral drawings, applying the V3 framework (sensor verification, analytical validation, and clinical validation) to establish reliability and clinical utility. Methods: Archimedes spiral drawings were recorded on a digitizing tablet from participants (n = 7) enrolled in a randomized placebo control double-blinded crossover pilot trial evaluating the efficacy of oral cannabinoids in reducing essential tremor. We developed an algorithm to calculate the mean and maximum tremor amplitude derived from the spiral tracings. We compared the digitally measured tremor amplitudes to manual measurement to evaluate sensor reliability, determined the test-retest reliability of the digital output across two short-interval repeated measures, and compared the digital measure to kinetic tremor severity graded using The Essential Tremor Rating Assessment Scale (TETRAS) score for spiral drawings. Results: This algorithm for automated assessment of kinetic tremor amplitude from digital spiral tracings demonstrated a high correlation with manual spot measures of tremor amplitude, excellent test-retest reliability, and a high correlation with human ratings of the TETRAS score for spiral drawing severity when the tremor severity was rated “slight tremor” or worse. Discussion: This digital measure provides a simple and clinically relevant evaluation of kinetic tremor amplitude that shows promise as a potential future endpoint for use in clinical trials of essential tremor.

Double lesion MRgFUS thalamotomy for essential tremor: 4.5-year outcomes and framework for assessing loss of efficacy and tremor progression

Background The essential tremor (ET) course to 54 months post-unilateral VIM/PSA magnetic resonance-guided focused ultrasound (MRgFUS) in the treated arm (TA) and non-treated arm (NTA) of 12 patients is reported. Methods Tremor severity was rated using Bain Findley spirography (BFS) scores in the TA and NTA. We divided follow-up into ‘Early’ (0–6 months) and ‘Late’ (6–54 months) phases, to minimise the effect of peri-lesion oedema resolution on the latter. Results The mean baseline BFS score was 6.2 in TA and 5.7 in the NTA. After unilateral VIM/PSA MRgFUS, mean BFS improved in TA at all subsequent time points (p < 0.001), with no significant differences between BFS scores at consecutive assessments or between 1 and 54 months, while the NTA BFS scores worsened between 12 and 24 months (p < 0.003). Three patients showed worsening of their TA BFS scores and an increasing NTA–TA BFS difference, indicating slower tremor worsening in TA compared to NTA, whilst one patient showed a greater rate of worsening in the TA compared to NTA BFS. Conclusion After 54 months, the beneficial effect of MRgFUS is usually maintained with any worsening of BFS scores in TA slower than in NTA. Loss of treatment benefit is rare.

Estimating Disability in Patients with Essential Tremor: Comparison of Tremor Rating Scale, Spiral Drawing, and Accelerometric Tremor Power.

Although performance rating scales, spiral drawing, water pouring, and accelerometry are commonly used to assess tremor severity, the extent to which their results correlate with impairment in activities of daily living (ADL) remains unclear. The aim was to identify the most effective predictors of ADL in essential tremor (ET). Forty ET patients were examined using The Essential Tremor Rating Assessment Scale (TETRAS), spiral drawing, volume of water spilled, and accelerometric tremor power. Root-mean-square error, R2, and F-test were calculated for models predicting TETRAS ADL subscore. TETRAS Performance Subscale explained the variability in TETRAS ADL with an R2 value of 0.686. Models incorporating spiral rating and accelerometric tremor power (R2 = 0.731) and water spillage volume (R2 = 0.756) were not statistically superior. TETRAS performance subscore predicted nearly 70% ADL impairment in ET patients. Incorporating the spiral rating, accelerometric tremor power, and water pouring test did not enhance ADL estimation.

Robot-assisted deep brain stimulation

Deep brain stimulation (DBS) is recognised as a safe and effective treatment for several movement disorders, namely essential tremor, Parkinson's disease, and dystonia, as well as for obsessive–compulsive disorder and refractory epilepsy. The main anatomical target of DBS is the basal ganglia. The DBS system comprises a pulse generator and surgically implanted electrodes. Lead placements must be accurate because the effects of DBS rely on the spatial restriction of the stimulation. Neurosurgical centres have started adopting robot-assisted DBS surgery. The results so far have been promising, with lead placement accuracy comparable to that of frame-based procedures. Additionally, robot-assisted procedures are shorter and less demanding on patients. Robot-assisted DBS can be used on patients who are fully awake or under general anaesthesia, as well as on children.

Ayurvedic Management of Kampavata

Kampavata is one among Vataja nanatmaja vyadhis. Acharya Charaka, Susrutha, Vagbhata, Madhavakara, Kashyapa mentioned Kampavata as Vepathu. It can be correlated with “Tremors” in modern science which is the most common movement disorder. The total number of people suffering from ET worldwide was 24.91 million in 2020 and incidence increases with age. Kampa is the prominent feature in Kampavata which is categorized as Sarvanga-kampa and Shiro-kampa. Kampa occurs due to Prakopa of Chalaguna which is the inherent quality of Vata dosha. The management of essential tremors in the conventional system of medicine is decreasing quality of life of patient with certain side effects like fatigue, impotence, bradycardia, reduced blood pressure, drowsiness, nausea, dizziness, ataxia, confusion, vertigo, paresthesia etc. By Ayurvedic intervention patient quality of life can be preserved. In the present clinical study patient was treated with Snehana and Brmhana line of management in the form of Shirodhara, Nasya and Samana oushadies like Sarvamayantakaghrta etc. The outcome of the study revealed good therapeutic efficacy and patient got remarkable relief in symptoms, that are assessed by TRG Essential tremor rating assessment scale (TETRAS©) V 3.1.

Baseline Depressive Symptoms as a Predictor of Incident Dementia in a Prospectively Followed Cohort of Elders with Essential Tremor

Introduction: Essential tremor (ET) patients may exhibit a variety of non-motor features, including cognitive decline and depressive symptoms. Studies of several neurodegenerative diseases link depression to cognitive decline, suggesting depression is an early marker of dementia. We examined whether baseline depressive symptoms predict incident dementia in elders with ET. Methods: Hundred and forty-one ET cases aged 70 years or older at baseline, enrolled in a prospective study of cognitive performance, took part in evaluations at baseline and at 18, 36, 54, and 72 months. Participants completed the Geriatric Depression Scale (GDS), a 30-item self-report measure of depressive symptoms, and a battery of neuropsychological tests and functional assessments, from which we derived cognitive diagnoses at each evaluation. Cox proportional hazards regression equations determined incident dementia risk based on participants’ baseline depression scores. Results: Mean baseline age was 81.5 ± 6.7 years. Higher baseline GDS scores were associated with increased risk of dementia in an unadjusted model (hazards ratio [HR] = 1.11, 95% confidence interval [CI] = 1.02–1.20, p = 0.01) and after controlling for baseline age, education, number of medications, and tremor onset age (HR = 1.13, 95% CI = 1.02–1.25, p = 0.02). Conclusion: Baseline depression scores predicted incident dementia in elders with ET. With each one-point increase in baseline depression score, there was a 13% increase in incident dementia risk. Given the published data that reported depression may be twice as high in elders with ET compared to controls, this association is particularly worrisome in the ET population.

Using a mixed-reality headset to elicit and track clinically relevant movement in the clinic.

21st century neurology will require scalable and quantitative tools that can improve neurologic evaluations over telehealth and expand access to care. Commercially available mixed-reality headsets allow for simultaneous presentation of stimuli via holograms projected into the real world and objective and quantitative measurement of hand movement, eye movement, and phonation. We created 6 tasks designed to mimic standard neurologic assessments and administered them to a single participant via the Microsoft HoloLens 2 mixed-reality headset. The tasks assessed postural hand tremor, finger tapping, pronation and supination of hands, hand and eye tracking of a center-out task, hand and eye tracking of a random motion task, and vocal assessment. We show the utility of the HoloLens for commonly used neurological exams. First, we demonstrate that headset-derived holograms can project hand movements and objects in 3D space, providing a method to accurately and reproducibly present test stimuli to reduce test-test variability. Second, we found that participant hand movements closely matched holographic stimuli using a variety of metrics calculated on recorded movement data. Third, we showed that the HoloLens can record and playback exam tasks for visual inspection, sharing with other medical providers, and future analysis. Fourth, we showed that vocal recordings and analysis could be used to profile vocal characteristics over time. Together, this demonstrates the versatility of mixed reality headsets and possible applications for neurological assessment. Administering components of the neurologic exam via a self-contained and commercially available mixed-reality headset has numerous benefits including detailed kinematic quantification, reproducible stimuli presentation from test to test, and can be self-administered expanding access to neurological care and saving hospital time and money. This work was supported by grants from the National Institutes of Health (NIH) (F30AG063468) (E.L.), (F31NS113395) (D.J.C), and the Pilot Grant Award from the University of Colorado Movement Disorders Center (D.J.C).

Prescription Drug Utilization among Patients with Essential Tremor: A Cross-Sectional Study of More Than 36,000 Patients.

Essential tremor (ET) is a chronic, progressive neurological disease that affects an estimated 7 million individuals in the United States (ie, 2.2% of the entire U.S. population). Despite its high prevalence, there are a few published studies on patterns of prescription medication use among patients. The aim was to examine prescription drug medication use among ET patients. This is a cross-sectional study of ET patients, age ≥40, with at least 1 prescription medication fill using the Optum's de-identified Clinformatics Data Mart Database from 2018 through 2019. We examined patterns of fills of key agents used to treat ET. The final sample comprised 36,839 ET patients in the United States; 89% had at least 1 prescription drug claim over a 2-year period, indicating that 9 of 10 ET patients take a medication to treat their disease. For each of the 3 most frequently prescribed medications, only a modest fraction (1/5 to 1/4) of patients were taking that medication. Adherence to these agents was 52% to 61%. A high percentage of patients had fills for more than 1 of the main agents we studied. These data illustrate a need for medication in the ET population. There is only 1 FDA-approved medication to treat ET, propranolol, and less than 25% of ET patients used this drug during our study period. At the same time, no single agent was utilized by more than one quarter of ET patients, adherence was low, and use of multiple agents was common. For such a common disease, the pharmacotherapeutic landscape is impoverished.

Clinical Conditions Targeted by OnabotulinumtoxinA in Different Ways in Medicine.

OnabotulinumtoxinA (BT-A) is used in different medical fields for its beneficial effects. BT-A, a toxin originally produced by the bacterium Clostridium botulinum, is widely known for its ability to temporarily paralyze muscles by blocking the release of acetylcholine, a neurotransmitter involved in muscle contraction. The literature continually reports new hypotheses regarding potential applications that do not consider blockade of acetylcholine release at the neuromuscular junction as a common pathway. In this opinion article, it is our aim to investigate the different pathway targets of BT-A in different medical applications. First of all, the acetylcholine effect of BT-A is used to reduce wrinkles for cosmetic purposes, in the treatment of urological problems, excessive sweating, temporomandibular joint disorders, obesity, migraine, spasticity in neurological diseases, and in various cases of muscle overactivity such as cervical dystonia, blepharospasm, and essential head tremor. In another potential pathway, glutamate A, CGRP, and substance P are targeted for pain inhibition with BT-A application in conditions such as migraine, trigeminal neuralgia, neuropathic pain, and myofascial pain syndrome. On the other hand, as a mechanism different from acetylcholine and pain mediators, BT-A is used in the treatment of hair loss by increasing oxygenation and targeting transforming growth factor-beta 1 cells. In addition, the effect of BT-A on the apoptosis of cancer cells is also known and is being developed. The benefits of BT-A applied in different doses to different regions for different medical purposes are shown in literature studies, and it is also emphasized in those studies that repeating the applications increases the benefits in the long term. The use of BT-A continues to expand as researchers discover new potential therapeutic uses for this versatile toxin.

Radiosurgical thalamotomy for the management of tremors: a systematic review and meta-analysis.

Medical treatment for tremors may include beta-blockers, primidone, dopaminergic, and anticholinergic drugs but it frequently leads to pharmacoresistance. Therefore, surgical treatment gained relevance as an alternative for those patients.We aim to evaluate radiosurgical thalamotomy as an effective and safe alternative to manage tremors.Pubmed (MEDLINE), Embase, Web of Science, and the Cochrane Library databases were systematically searched for potential articles that evaluated radiosurgical thalamotomy for the management of tremor.Our analysis included 12 studies with 545 patients, 226 of whom were female. Of these, 64.6% of patients were diagnosed with essential tremor (ET), 34.6% with Parkinson's disease (PD), and 0.8% with both ET and PD. The FTM-TRS global score (MD -5.46; 95% CI [-10.44]-[-0.47]; I2 = 52%) and the drawing (MD -1.40; 95% CI [-2.03]-[-0.76]; I2 = 93%), drinking (MD -1.60; 95% CI [-1.82]-[-1.37]; I2 = 40%), and writing (MD -1.51; 95% CI [-1.89]-[-1.13]; I2 = 89%) grades showed significantly lower mean differences, favoring radiosurgical thalamotomy. A pooled proportion of 12% presented with tremor unchanged, while 38% presented with total elimination of tremor. Adverse events included: major paresis, minor paresis, dysarthria, and numbness. Thus, radiosurgical thalamotomy is a safe alternative for tremors resistant to medication, particularly in high-risk patients for RF or DBS procedures. The recommended dose of 130 to 150Gy is effective and well-tolerated. However, randomized controlled trials (RCTs) are needed to understand the unpredictability of tissue response to radiation.

Bibliometric analysis on Deep Brain StimulationProcedures Conducted Between 2000-2023

Objective: Deep brain stimulation (DBS) is a treatment method that uses electrodes to stimulate the brain, affecting brain activity and potentially causing medical conditions. It is commonly used to treat Parkinson's disease, essential tremor, dystonia, epilepsy, Tourette syndrome, and obsessive-compulsive disorder. This bibliometric study examines advanced bibliometric parameters in articles published since 2000, focusing on trends in publishing organizations, countries, funding sources, international collaborations, and trend keywords. Materials and Methods: We have searched the Web of Science database to find articles on DBS which published since 2000. The search was performed by using the MESH keywords releated to "Deep brain stimulation". Results: This study presents a comprehensive analysis of 4,601 articles on Deep Brain Stimulation (DBS) from 2000 to 2023, focusing on publication trends, properties, funding, country contributions, and international collaborations. Noteworthy findings include a peak of 413 publications in 2020 and 14,992 citations in 2021. The overall trajectory demonstrates a significant increase in scientific output, with an average of 31.9 citations per article. Publication properties reveal diverse access categories, including 66 Early Access and 2,136 Open Access articles. The majority of records are in the Science Citation Index Expanded (93.980%). Clinical Neurology dominates research topics with 63.464% representation. Funding sources highlight major contributions from the USA, Germany, and China. The USA leads in research output, while the University of Toronto tops institutions. Major journals include "Stereotactic and Functional Neurosurgery" and "Movement Disorders." Keyword analysis emphasizes common themes like "deep brain stimulation" and "Parkinson's disease." International collaborations involve researchers from 75 countries, with the USA leading in total link strength. This study contributes valuable insights into the global landscape of DBS research. Conclusion: This analysis highlights the dynamic nature of Deep Brain Stimulation research, highlighting global collaboration and diverse topics, emphasizing the crucial role of key countries, institutions, and journals.

REM sleep behavior disorder and Prodromal Parkinson’s Disease in patients with Essential Tremor

Several studies suggested the presence of non-motor symptoms in Essential Tremor (ET), including REM sleep behavioral disorder (RBD). RBD is an essential criterion for Prodromal Parkinson's Disease (PPD), suggesting a link between ET and PD. Our objective was to assess the prevalence and features of ET patients with RBD and PDD.RBD was diagnosed by questionnaire screening, followed by polysomnography. PPD risk factors and prodromic markers were assessed with a structured protocol. Patients were characterized regarding tremor features. ET patients with RBD (ET-RBD) and PPD (ET-PPD) were compared to patients without RBD (ET-nonRBD) and without PPD (ET-nonPPD), respectively. ET-RBD patients were also compared with a group of isolated RBD (iRBD) regarding PPD features.We assessed a total of 64 ET patients. Five (8.3 %) and 4 (6.3 %) had criteria for RBD and PPD, respectively. ET-RBD patients did not differ from ET-nonRBD except for a higher prevalence of PPD. There were no significant differences between ET-RBD and iRBD (n = 12) groups. ET-PPD had a higher prevalence of positive DaT-Scans and RBD compared to ET-nonPPD. Three ET-RBD patients had PPD and 3 ET-PPD had RBD.Both RBD and PPD are more frequent in ET patients than in general aged population but not related with specific tremor features. ET-RBD patients did not differ significantly from iRBD patients, a group prone to develop PD. These data suggest a link between ET and PD and are in accordance with studies showing an increase incidence of lewy-body pathology and PD in ET populations.

Reviewing the Diagnostic Performance of 99mTc-TRODAT-1 Imaging in Distinguishing Idiopathic Parkinson's Disease from Parkinson-Plus Syndromes

Abstract Aim Diagnosing movement disorders can be challenging owing to their similar clinical presentations with other neurodegenerative and basal ganglia disorders, like idiopathic Parkinson's disease (IPD), essential tremors (ET), vascular parkinsonism, multiple system atrophy (MSA), and progressive supranuclear palsy (PSP). Technetium-99m labeled tropane derivative (99mTc-TRODAT-1) imaging can help in diagnosing Parkinson's disease at an early stage to help early initiation of the treatment. The current study aimed to evaluate the role of 99mTc-TRODAT-1 imaging in differentiating IPD and Parkinson-plus syndromes (PPS). Material and Methods We have analyzed 38 patients, referred to our department for 99mTc-TRODAT imaging. These patients were thoroughly evaluated in the movement disorder clinic at our institute and had a possible/ probable diagnosis of IPD, Hoehn and Yahr (H&amp;Y) stage I/II (n = 28) or PPS (PSP [n = 06] and MSA [n = 04]). Striatal uptake ratio (SUR) was calculated in all the patients and data was statistically analyzed. Results The mean age of IPD, PSP, and MSA groups was 56.5 ± 12.15, 65.2 ± 11.1, and 51.2 ± 3.9 years, respectively. On qualitative evaluation, all patients had reduced striatal uptake on 99mTc-TRODAT imaging, with 31/38 patients showed a greater reduction in putaminal uptake compared with the caudate nucleus. On semiquantitative evaluation, mean total SUR was 0.58 ± 0.27, 0.53 ± 0.31, and 0.91 ± 0.20 in IPD, PSP, and MSA groups, respectively. The total SUR was lowest in the PSP group followed by IPD, but MSA had relatively higher SUR, although the difference was not statistically significant. Among the IPD patient group, 25/28 patients (89.3%) experienced a greater reduction in SUR values in the striatum contralateral to the side, where motor symptoms first manifested at disease onset. Conclusion 99mTc-TRODAT is a potential imaging biomarker for the evaluation of presynaptic dopaminergic dysfunction in patients with movement disorders. In our study cohort, mean SUR values were lowest for the PSP group followed by IPD and MSA group, which was in concordance with previous studies. However, the difference between SUR values in these two groups was not statistically significant. The present study emphasizes that the capacity of 99mTc-TRODAT-1 imaging alone for diagnosing IPD from PPS is constrained, although it offers a precise approach for distinguishing patients with IPD from those with essential tremors, drug-induced, or psychogenic parkinsonism. Consequently, more specific imaging biomarkers are needed to effectively differentiate between patients with IPD and those with PPS.

Systematic review-based guideline "Parkinson's disease" of the German Society of Neurology: diagnostic use of transcranial sonography.

Transcranial brain parenchyma sonography (TCS) has been recommended as a tool for the early and differential diagnosis of Parkinson's disease (PD) in German and European clinical guidelines. Still, the brain structures to be examined for the diagnostic questions and the requirements for being a qualified investigator were not specified in detail. These issues have now been addressed in the 2023 update of the clinical guideline on PD by the German Society of Neurology (DGN). The recommendations were based on a systematic literature review following PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. Three diagnostic questions were defined: (1) What is the accuracy of TCS in the differential diagnosis of PD versus atypical and secondary Parkinsonian syndromes? (2) What is the accuracy of TCS in the differential diagnosis of PD versus essential tremor? (3) What is the accuracy of TCS in the diagnosis of PD in persons with typical early symptoms, compared with the diagnosis established by clinical follow-up? The brain structures to be assessed and the level of recommendation were formulated for these questions. The training requirements for being regarded as qualified TCS investigator were stipulated by the responsible medical societies (German Society of Ultrasound in Medicine, DEGUM; German Society for Clinical Neurophysiology and Functional Imaging, DGKN). Finally, the recommendations for these diagnostic questions reached strong consensus (each ≥ 97%) of the guideline committee. Here, the details of review and recommendations are presented. The updated guideline clarifies the diagnostic uses and limitations of TCS in PD.

Assessing ChatGPT Ability to Answer Frequently Asked Questions About Essential Tremor.

Large-language models (LLMs) driven by artificial intelligence allow people to engage in direct conversations about their health. The accuracy and readability of the answers provided by ChatGPT, the most famous LLM, about Essential Tremor (ET), one of the commonest movement disorders, have not yet been evaluated. Answers given by ChatGPT to 10 questions about ET were evaluated by 5 professionals and 15 laypeople with a score ranging from 1 (poor) to 5 (excellent) in terms of clarity, relevance, accuracy (only for professionals), comprehensiveness, and overall value of the response. We further calculated the readability of the answers. ChatGPT answers received relatively positive evaluations, with median scores ranging between 4 and 5, by both groups and independently from the type of question. However, there was only moderate agreement between raters, especially in the group of professionals. Moreover, readability levels were poor for all examined answers. ChatGPT provided relatively accurate and relevant answers, with some variability as judged by the group of professionals suggesting that the degree of literacy about ET has influenced the ratings and, indirectly, that the quality of information provided in clinical practice is also variable. Moreover, the readability of the answer provided by ChatGPT was found to be poor. LLMs will likely play a significant role in the future; therefore, health-related content generated by these tools should be monitored.

Probabilistic Tractography-Based Tremor Network Connectivity in Tremor Dominant Parkinson's Disease and Essential Tremor plus.

Background: The basal ganglia-thalamocortical (BGTC) and cerebello-thalamocortical (CTC) networks are implicated in tremor genesis; however, exact contributions across disorders have not been studied. Objective: Evaluate the structural connectivity of BGTC and CTC in tremor-dominant Parkinson's disease (TDPD) and essential tremor plus (ETP) with the aid of probabilistic tractography and graph theory analysis. Methods: Structural connectomes of the BGTC and CTC were generated by probabilistic tractography for TDPD (n = 25), ETP (ET with rest tremor, n = 25), and healthy control (HC, n = 22). The Brain Connectivity Toolbox was used for computing standard topological graph measures of segregation, integration, and centrality. Tremor severity was ascertained using the Fahn-Tolosa-Marin tremor rating scale (FTMRS). Results: There was no difference in total FTMRS scores. Compared with HC, TDPD had a lower global efficiency and characteristic path length. Abnormality in segregation, integration, and centrality of bilateral putamen, globus pallidus externa (GPe), and GP interna (GPi), with reduction of centrality of right caudate and cerebellar lobule 8, was observed. ETP showed reduction in segregation and integration of right GPe and GPi, ventrolateral posterior nucleus, and centrality of right putamen, compared with HC. Differences between TDPD and ETP were a reduction of strength of the right putamen, and lower clustering coefficient, local efficiency, and strength of the left GPi in TDPD. Conclusions: Contrary to expectations, TDPD and ETP may not be significantly different with regard to tremor pathogenesis, with definite overlaps. There may be fundamental similarities in network disruption across different tremor disorders with the same tremor activation patterns, along with disease-specific changes.

Could the Anatomic Variants of the Superior Thalamic Vein (STV) Be Considered a Possible Landmark for Target Identification in Magnetic-Resonance-Guided Focused Ultrasound Procedures? A Pilot Study Using Susceptibility Weighted Imaging Sequences.

During magnetic-resonance-guided focused ultrasound ablation of the ventral intermediate thalamic nucleus (VIM) for essential tremor (ET) and Parkinson's disease (PD), targeting is generally performed using a standard atlas-based stereotactic approach. The purpose of our work is to evaluate the anatomic variations in the venous vasculature of the thalamus in patients treated with MRgFUS, as a possible landmark for targeting. We retrospectively evaluated the relationship between the obtained thalamotomy lesion and the ipsilateral superior thalamic vein (STV). A total of 36 patients (25 ET and 11 PD) who underwent MRgFUS treatment were evaluated, and the STV was studied with susceptibility weighted imaging (SWI) sequences. Based on the axial SWI images, the distance between the STV and the center of the lesion at the presumed site of the VIM was measured in follow-up MRI images one month after treatment. Statistical analysis shows that there is a correlation between the STV and the presumed site of the VIM. The STV visible in SWI could be used as an additional, real-time, and patient-specific anatomical landmark for VIM identification during MR examination and just before and during FUS treatment.

Botulinum Toxin in Treatments for Abnormal Movements

Introduction: Botulinum toxin is crucial for reducing sequelae in movement disorders such as Parkinson's. It blocks muscle contractions and improves quality of life, being used in both aesthetic and medical treatments. Methodology: A non-experimental longitudinal design was adopted, observing variables at multiple time points without manipulation. A mixed approach (qualitative and quantitative) was used with adults over 30 years old without Parkinson's history. The review included documents from PubMed, Scopus, and Scielo, applying rigorous inclusion and exclusion criteria. Objective: To evaluate the efficacy of botulinum toxin in treating abnormal movements in Parkinson's and understand its long-term effects. Results: Botulinum toxin type A reduces tremors by blocking acetylcholine. It improves motor symptoms of Parkinson's and essential tremor but requires frequent and costly treatments. There is a risk of developing antibodies that decrease its effectiveness. Discussion: It offers significant benefits, but its high cost and the need for frequent treatments are challenges. Patients report satisfaction in short-term studies, but more long-term research is needed. Conclusions: Promising for movement disorders, especially Parkinson's, although limited by cost and duration of effect. Future research should seek to extend therapeutic effects and reduce costs.

Deep brain stimulation in Latin America in comparison with the US and Europe in a real-world population: indications, demographics, techniques, technology, and adverse events.

The aim of this study was to provide geographic comparisons of deep brain stimulation (DBS) procedures in Latin America with the US and Europe regarding primary indications, demographic information, clinical and device-related adverse events, technology used, and patient outcomes using the Medtronic Product Surveillance Registry data as of July 31, 2021. Two thousand nine hundred twelve patients were enrolled in the registry (2782 received DBS and 1580 are currently active). Fourteen countries contributed 44,100 years of device experience to the registry. DBS centers in Latin America are located in Colombia (n = 3), Argentina (n = 1), Brazil (n = 1), and Mexico (n = 1). Fisher's exact test was used to compare the difference in proportions of categorical variables between regions. The Wilcoxon signed-rank test was used for the EQ-5D index score change from baseline to follow-up. The most common indication for DBS was Parkinson's disease across all regions. In Latin America, dystonia was the second most common indication, compared to essential tremor in other regions. There was a striking finding with respect to age-patients were an average of 10 years younger at DBS implantation in Latin America. This difference was most likely due to the greater number of patients with dystonia receiving the device implants. The intraoperative techniques were quite similar, showing the same level of quality and covering the main principles of the surgeries with some variations in the brand of frames, planning software, and microrecording systems. Rechargeable batteries were significantly more common in Latin America (72.37%) than in the US (6.44%) and Europe (9.9%). Staging of the DBS procedure differed, with only 11.84% in Latin America staging the procedure compared with 97.58% and 34.86% in the US and Europe, respectively. The EQ-5D score showed significant improvements in all regions during the first 6-12 months (p < 0.0001). However, the 24-month follow-up only showed an improvement in the scale for Latin America (p < 0.0001). DBS was performed in Latin America with similar indications, techniques, and technology as in the US and Europe. Important differences were found, with Latin America implementing more regular use of rechargeable devices, including younger patients at the time of surgery, and showing more sustained quality of life improvements at 24 months of follow-up. The authors hypothesize that these disparities stem from differences in resources among regions. However, more studies are needed to standardize DBS practice across the world to improve patients' quality of life and provide high-quality care.