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A 50-year-old male patient presented with a 10-year history of progressive cerebellar ataxia, multifocal dystonia with dystonic tremors, and oculomotor abnormalities including bilateral ptosis, slow saccades, and reduced range of ocular movements. There were no signs of cognitive impairment, parkinsonism, autonomic dysfunction, or muscle weakness, and the family history was unremarkable. This case presents the diagnostic approach to adult-onset cerebellar ataxia with dystonia and abnormal eye movements. In this era of genomic testing, our case highlights the role of clinical phenotyping and the utility of whole-exome sequencing in ataxias.

Background: The merits of classifying the heterogeneous group of essential tremors into essential tremor (ET) and essential tremor plus (ETP) are debated., Objectives: We studied the electrophysiological and spiral characteristics of tremor in ET and ETP., Methods: We reviewed standardized videos from a tremor database and clinically classified patients into ET, ETP, or dystonic tremor (DT). The following variables were derived from combined tri-axial accelerometry-surface electromyography (EMG)-peak frequency, total power, peak power, full width half maximum, tremor stability index and EMG-coherence. We analyzed hand-drawn spirals to derive mean deviation, tremor variability, inter-, and intra-loop widths. We compared these variables among the groups., Results: We recruited 72 participants (81.9% male) with mean age 47.7 ± 16.1 years and Fahn-Tolosa-Marin Tremor Rating Scale total score 31.1 ± 14.1. Patients with ET were younger (P = 0.014) and had less severe tremor (P = 0.020) compared to ETP and DT. In ETP group, 48.6% had subtle dystonia. Peak frequency was greater in ETP (7.3 ± 0.3 Hz) compared to DT (6.1 ± 0.4 Hz; P = 0.024). Peak power was greater in ETP and DT for postural tremor. Rest tremor was recordable on accelerometry in 26.7% of ET. Other variables were similar among the groups., Conclusion: Electrophysiological evaluation revealed postural tremor of frequency 6 to 7 Hz in ET, ETP, and DT with subtle differences more severe tremor in ETP and DT, and higher frequency in ETP compared to DT. Our findings suggest a similar tremor oscillator in these conditions, supporting the view that these entities are part of a spectrum of tremor disorders, rather than distinct etiological entities., (© 2023 International Parkinson and Movement Disorder Society.)

Objective: Dystonias are relatively rare disorders characterized by sustained or intermittent muscle contractions causing abnormal movements or postures. Generalized dystonia is a therapeutic challenge because medications are unable to control dystonia adequately in most patients. These patients may be candidates for surgical therapy. The commonly used surgical procedures in these patients are pallidotomy and deep brain stimulation. Limited studies are available on the role of pallidotomy in children with acquired/heredodegenerative generalized dystonia. The objective of this study was to describe the authors' experience with bilateral pallidotomy in this group of patients., Methods: The authors retrospectively reviewed all pediatric patients (less than 18 years of age) with acquired/heredodegenerative generalized dystonia who underwent bilateral simultaneous pallidotomy at their center between January 2014 and January 2021. Burke-Fahn-Marsden Dystonia Rating Scale (BFMDRS) scores before and after surgery were recorded. Complications arising after the procedure were recorded as well., Results: Ten patients (8 male and 2 female) with a mean (range) age of 11.1 (5-17) years were included in this study. The mean duration between disease onset and surgical intervention was 3.9 years. Two patients presented in status dystonicus. The mean ± SD (range) preoperative BFMDRS score of the patients without status dystonicus (n = 8) was 80 ± 18.9 (59.5-108). The mean ± SD BFMDRS score at the time of discharge from the hospital after surgery was 58.8 ± 37.9. Three patients had more than 20% change in BFMDRS score at the time of discharge from the hospital. The mean improvement was 25.5% at the end of 1 year. Of 5 surviving patients in the non-status dystonicus group, 3 patients had more than 40% change in BFMDRS score while the other 2 patients developed recurrence at the last follow-up (4.5 years). Status dystonicus abated after bilateral pallidotomy in both patients. Permanent bulbar complications were seen in 2 patients., Conclusions: Bilateral pallidotomy may result in clinically significant improvement in children with acquired/heredodegenerative generalized dystonia, although the benefits should be closely weighed against the risk of irreversible bulbar dysfunction. It is a viable option for children in resource-limited settings.

Importance: There is an unmet need for safe and efficacious treatments for upper-extremity dystonic tremor (DT). To date, only uncontrolled retrospective case series have reported the effect of botulinum neurotoxin (BoNT) injections on upper-extremity DT., Objective: To assess the effect of BoNT injections on tremor in patients with upper-extremity DT., Design, Setting, and Participants: In this placebo-controlled, parallel-group randomized clinical trial, 30 adult patients with upper-extremity DT treated at a movement disorder clinic in a tertiary care university hospital were randomized in a 1:1 ratio to BoNT or saline injection, 0.9%, using a computer-generated randomization sequence. Randomization was masked using opaque envelopes. The participant, injector, outcome assessor, and statistician were blinded to the randomization. Participants were recruited between November 20, 2018, and December 12, 2019, and the last follow-up was completed in March 2020., Interventions: Participants received electromyographically guided intramuscular injections of BoNT or placebo into the tremulous muscles of the upper extremity. Injection patterns and doses were individualized according to tremor phenomenologic findings., Main Outcomes and Measures: The primary outcome was the total score on the Fahn-Tolosa-Marin Tremor Rating Scale 6 weeks after the intervention. Outcomes were assessed at baseline, 6 weeks, and 12 weeks. All patients were offered open-label BoNT injections after 12 weeks and reassessed 6 weeks later., Results: A total of 48 adult patients with a diagnosis of brachial dystonia with DT were screened. Fifteen were ineligible and 3 refused consent; therefore, 30 patients (mean [SD] age, 46.0 [18.6] years; 26 [86.7%] male) were recruited, with 15 randomized to receive BoNT and 15 to receive placebo. In the intention-to-treat group, the Fahn-Tolosa-Marin Tremor Rating Scale total score was significantly lower in the BoNT group at 6 weeks (adjusted mean difference, -10.9; 95% CI, -15.4 to -6.5; P < .001) and 12 weeks (adjusted mean difference, -5.7; 95% CI, -11.0 to -0.5; P = .03). More participants in the BoNT group reported global improvement on the Global Impression of Change (PGIC) assessment (PGIC 1, 2, and 3: BoNT: 4 [26.7%], 6 [40.0%], and 5 [33.3%]; placebo: 5 [33.3%], 10 [66.7%], and 0, respectively; P = .047). Subjective hand weakness (BoNT: 6 [40.0%]; placebo: 4 [28.6%], P = .52) and dynamometer-assessed grip strength (mean difference, -0.2 log10[kgf/m2]2/Hz-Hz; 95% CI, -0.9 to 0.4 log10[kgf/m2]2/Hz-Hz; P = .45) were similar in both groups., Conclusions and Relevance: In this randomized clinical trial, botulinum neurotoxin injections were superior to placebo in reducing tremor severity in upper-extremity DT. An individualized approach to muscle selection and dosing was beneficial without unacceptable adverse effects., Trial Registration: Clinical Trials Registry of India (http://ctri.nic.in) Identifier: CTRI/2018/02/011721.

Background: Deep brain stimulation (DBS) is currently the preferred surgical treatment for various movement disorders. Pallidotomy is an effective procedure for patients with dystonia and Parkinson's disease and was the surgical treatment of choice before the advent of DBS. However, it can be the preferred modality in immunocompromised patients and those patients who cannot afford DBS due to financial constraints. Hypophonia, dysarthria and dysphagia are the most significant complications of bilateral pallidotomy., Objective: The aim of this study was to present the surgical technique and nuances involved in bilateral simultaneous pallidotomy in a patient with generalized dystonia., Procedure: A 30-year male with primary generalized dystonia presented to us with preoperative Burke-Fahn-Marsden (BFM) Dystonia Rating Scale of 24. After acquiring preoperative volumetric 3T MRI and stereotactic CT, bilateral pallidotomy was done under general anesthesia. There were no procedure related complications., Results: At two months of follow-up, his BFM dystonia score improved from 24 to 4.5., Conclusion: Appropriately acquired volumetric MRI, meticulous planning and meticulously performed surgical procedure can help in achieving good outcome and minimize the complications., Competing Interests: None

The pathophysiology of dystonia in Wilson disease (WD) is complex and poorly understood. Copper accumulation in the basal ganglia, disrupts dopaminergic pathways, contributing to dystonia's development via neurotransmitter imbalance. Despite advances in diagnosis and management, WD with dystonia remains a challenging condition to treat. We aim to report the unprecedented co-occurrence of pathogenic genetic variants in both the ATP7B and KMT2B genes in a patient with WD. A 13-year-old male presented at 12 with dysarthria and bilateral Kayser-Fleischer rings. Over months, dystonia spread to his left foot, upper limb, and trunk, accompanied by slowed daily activities. Diagnostic tests included MRI for brain structure, abdominal ultrasound for liver function, serum ceruloplasmin and copper levels to assess copper metabolism, and 24-hour urine copper tests for excretion levels. Whole exome sequencing was conducted using genomic DNA from peripheral blood samples. Variant classification followed guidelines from the American College of Medical Genetics and Genomics. The sequencing revealed compound heterozygous pathogenic variants in the ATP7B gene: NM_000053.4:c.2165dupT and NM_000053.4:c.813C>A. A pathogenic variant in the KMT2B gene, NM_014727:c.3052delA, was identified. This case highlights WD co-occurrence with ATP7B and KMT2B mutations, suggesting KMT2B as a potential genetic modifier. [ABSTRACT FROM AUTHOR]

In patients with movement disorders, voluntary movements can sometimes be accompanied by unintentional muscle contractions in other body regions. In this review, we discuss clinical and pathophysiological aspects of several motor phenomena including mirror movements, dystonic overflow, synkinesia, entrainment and mirror dystonia, focusing on their similarities and differences. These phenomena share some common clinical and pathophysiological features, which often leads to confusion in their definition. However, they differ in several aspects, such as the body part showing the undesired movement, the type of this movement (identical or not to the intentional movement), the underlying neurological condition, and the role of primary motor areas, descending pathways and inhibitory circuits involved, suggesting that these are distinct phenomena. We summarize the main features of these fascinating clinical signs aiming to improve the clinical recognition and standardize the terminology in research studies. We also suggest that the term "mirror dystonia" may be not appropriate to describe this peculiar phenomenon which may be closer to dystonic overflow rather than to the classical mirror movements. [ABSTRACT FROM AUTHOR]

This article discusses a case study of a 12-year-old boy with THAP1-associated dystonia, a condition that mimics neurodegeneration with brain iron accumulation (NBIA). The boy presented with childhood onset, generalized dystonia that progressively worsened over time. Neurological examination revealed dystonia involving various body regions, along with bradykinesia and rigidity. Magnetic resonance imaging (MRI) showed hypointensity in the bilateral globus pallidi, a finding typically associated with NBIA. However, genetic testing revealed a pathogenic mutation in the THAP1 gene, confirming the diagnosis of DYT6 dystonia. Treatment with levodopa and other medications resulted in mild improvement. This case adds to the evidence that DYT-THAP1 should be considered as a mimic of NBIA. [Extracted from the article]

OBJECTIVE: To develop an automated algorithm to detect, quantify, and differentiate between tremor using pen-on-paper spirals. METHODS: Patients with essential tremor (n = 25), dystonic tremor (n = 25), Parkinson’s disease (n = 25), and healthy volunteers (HV, n = 25) drew free-hand spirals. The algorithm derived the mean deviation (MD) and tremor variability from scanned images. MD and tremor variability were compared with 1) the Bain and Findley scale, 2) the Fahn–Tolosa–Marin tremor rating scale (FTM–TRS), and 3) the peak power and total power of the accelerometer spectra. Inter and intra loop widths were computed to differentiate between the tremor. RESULTS: MD was higher in the tremor group (48.9±26.3) than in HV (26.4±5.3; p < 0.001). The cut-off value of 30.3 had 80.9% sensitivity and 76.0% specificity for the detection of the tremor [area under the curve: 0.83; 95% confidence index (CI): 0.75, 0.91, p < 0.001]. MD correlated with the Bain and Findley ratings (rho = 0.491, p = 0 < 0.001), FTM–TRS part B (rho = 0.260, p = 0.032) and accelerometric measures of postural tremor (total power, rho = 0.366, p < 0.001; peak power, rho = 0.402, p < 0.001). Minimum Detectable Change was 19.9%. Inter loop width distinguished Parkinson’s disease spirals from dystonic tremor (p < 0.001, 95% CI: 54.6, 211.1), essential tremor (p = 0.003, 95% CI: 28.5, 184.9), or HV (p = 0.036, 95% CI: -160.4, -3.9). CONCLUSION: The automated analysis of pen-on-paper spirals generated robust variables to quantify the tremor and putative variables to distinguish them from each other. SIGNIFICANCE: This technique maybe useful for epidemiological surveys and follow-up studies on tremor. [ABSTRACT FROM AUTHOR]

Background: Early evidence suggests good response to pallidal deep brain stimulation (DBS) in DYT‐KMT2B. Objectives: We aimed to conduct a systematic review and meta‐analysis to assess outcomes and identify predictors of good outcome following GPi‐DBS in DYT‐KMT2B. Methods: We searched MEDLINE, Cochrane and MDS‐abstracts databases using the MeSH terms "KMT2B and DYT28". We included studies that reported objective outcomes following GPi‐DBS in DYT‐KMT2B. The BFMDRS‐M (Burke‐Fahn‐Marsden Dystonia Rating Scale‐ Movement) total scores pre‐ and post‐surgery were used to quantify outcomes. We calculated pooled effects using a random effects meta‐analysis and used meta‐regression to identify potential effect modifiers. Multiple linear regression using individual patient data was used to identify predictors of good outcome (>50% improvement from baseline on BFMDRS‐M). Results: Initial searches screened 132 abstracts of which 34 full‐text articles were identified to be of potential interest. Ten studies reporting 42 individual patients, met the inclusion/exclusion criteria and were included in the final review. The mean age at onset was 6.4 ± 5.7 years and 40% were male. The median follow‐up was 12 months (range: 1–264 months). GPi‐DBS resulted in median BFMDRS‐M improvement of 42.7% (range: −103.5% to 95.9%) postoperatively. Pooled proportion of patients experiencing clinical improvement >50% on BFMDRS‐M was 41% (95% CI: 27%–57%). Male gender [β: 22.6, 95% CI: 8.0–37.3, P = 0.004), and higher pre‐operative BFMDRS‐M score [β: 0.62, 95% CI: 0.36–0.87, P < 0.001) were independently associated with better outcome. Conclusion: KMT2B‐associated dystonia responds effectively to pallidal stimulation. The outcome is better in males and those with more severe dystonia at baseline. [ABSTRACT FROM AUTHOR]

Objective: To describe the genotype--phenotype correlations in Indian patients with THAP1 mutations. Background: THAP1 variants are among the earliest identified mutations associated with isolated generalized dystonia. A number of different mutation types and locations in the THAP1 gene have been associated with a range of severity and dystonia phenotypes, but, as yet, it has been difficult to identify clear genotype--phenotype patterns. Here, we will describe six patients from four families with THAP1 mutations. Methods: Participants were recruited as part of the Indian Movement Disorder Registry and Biobank. We performed whole-exome sequencing (WES) on DNA isolated from peripheral blood using illumina platform with mean 80--100x coverage. Pathogenic variants were identified by using GATK pipelines. The variant was classified based on the joint guidelines of American College of Medical Genetics and Genomics and Association of Molecular Pathology. Results: We identified six patients from four families with a history of dystonia (five isolated and one combined (myoclonus)). Out of these six, 80% were male, the mean age of onset was 18.2 ± 18.3 years, and family history was positive in 66.7 %. WES identified four variants in THAP1 gene. In all six patients, we identified heterozygous mutations in the THAP1 gene. In family 1 (patient 1), WES revealed a pathogenic c.152G>C (p.Ser51Thr) missense variant. In family 2 (patients 2 and 3), we found a pathogenic c.85C>T (p.Arg29Ter) nonsense variant. In family 3 (patients 4 and 5), we found a pathogenic c.190&lowbar;191del (p.Lys64GlufsTer21) deletion variant. In family 4 (Patient 6), we found the pathogenic c.164C>A (p.Ser55Ter) nonsense variant. Five patients with early-onset generalized dystonia had generalized/multifocal dystonia with predominant cervicobrachial involvement. The patient with adult-onset dystonia had bibrachial dystonia with dystonic hand tremors. Tremors were present in five out of six patients. Laryngeal involvement were present in four patients. Conclusion: In this series of THAP1, dystonia including four patients with novel pathogenic variants phenotype was consistent with early-onset generalized dystonia, cervicobrachial predominant with prominent tremor. [ABSTRACT FROM AUTHOR]

Variants in the TUBB4A gene are associated with dystonia (DYT- TUBB4A), Hypomyelination with Atrophy of the Basal Ganglia and Cerebellum (H-ABC) and spastic paraplegia. Phenotypes intermediate to these three broad phenotypes are also observed. These are rare disorders, and data from diverse populations remains limited. We report seven Indian cases with dystonia phenotype related to TUBB4A mutation. Among these seven patients, age at onset ranged from 5 to 48 years. Five patients had cranio-cervical onset of dystonia. One patient had prominent parkinsonism with dystonia. Patients responded well to botulinum toxin injected for laryngeal, cervical and jaw dystonia. The patient with parkinsonism responded well to levodopa, albeit with development of dyskinesias. Apart from the common p.Arg2Gly variant in three patients with DYT- TUBB4A , other variants included p.Arg262Pro, p.Arg39Cys and p.Asp245Asn. We report the first collection of cases with TUBB4A mutation from India. We expand the phenotype to include levodopa-responsive parkinsonism. Indian patients, consistent with global literature, harbor prominent adductor dysphonia, cervical and jaw dystonia, which responds well to botulinum treatment. • Indian patients with DYT-TUBB4A had severe adductor spasmodic dysphonia and prominent cervical involvement. • A novel Arg262Pro variant was associated with levodopa-responsive parkinsonism. • Intermediate phenotypes, with prominent dystonia and white matter involvement, showed relatively severe clinical features. [ABSTRACT FROM AUTHOR]