This study examines the efficacy of single photon emission computed tomography/computed tomography (SPECT/CT) guided BoNT-A injections for alleviating motor and non-motor symptoms in cervical dystonia (CD) patients. It also assesses the accuracy of SPECT/CT muscle imaging in identifying responsible muscles and analyzes the quantitative significance of the SUVmax index. A total of 102 patients diagnosed with primary cervical dystonia (CD) were recruited and assessed at baseline, as well as at 2, 4, 8, 12, and 24 weeks post-botulinum toxin A (BoNT-A) injection. Among these patients, 79 underwent SPECT/CT imaging (SPECT/CT group), and 23 did not (control group). Both groups received BoNT-A injections guided by EMG, and their symptom improvements were compared. In the SPECT/CT group, the distribution of responsible muscles and its correlation with clinical phenotypes were analyzed. Furthermore, in a subset of 51 CD patients, overall and mean SUVmax of responsible muscles were quantified, and their correlation with the severity of motor symptoms was analyzed. In both the Tsui and TWSTRS scales, the SPECT/CT group (n = 69) showed significantly higher overall improvement rates compared to the control group (n = 23), with statistically significant differences. In 79 CD patients, SPECT/CT imaging showed that common responsible muscles were the splenius capitis (SPCa), levator scapulae (Lev), splenius cervicis (SPCe), semispinalis capitis (SmCa), obliquus capitis inferior (OCI), and semispinalis cervicis (SSc). The deflection in CD patients was mainly influenced by the ipsilateral SPCa, SPCe, Lev, OCI, longissimus cervicis (LGc), and contralateral sternocleidomastoid muscle (SCM). In 51 CD patients, significant positive correlations were found between overall SUVmax of responsible muscles and motor symptom scores, as well as between the mean SUVmax of responsible muscles and motor symptom scores. SPECT/CT muscle imaging significantly improves motor symptoms in CD patients when used for BoNT-A injections. It effectively identifies responsible muscles, and its SUVmax value serves as an objective indicator of motor symptom severity. SPECT/CT shows promise as a valuable tool for diagnosing and treating CD.

Movement disorder emergencies at a tertiary-care center in West Bengal, India: Spectrum, etiologies, diagnostic implications.

THAP1-associated dystonia (DYT-THAP1) is classically described as an early-onset disorder with craniocervical involvement and potential for generalization. However, increasing reports suggest a broader phenotypic spectrum, including adult-onset presentations. We aimed to characterize the clinical phenotype of genetically confirmed DYT-THAP1 with age at onset ≥ 40 years, and to highlight an illustrative case. A scoping review was conducted following Joanna Briggs Institute methodology. Comprehensive searches of PubMed, MDSGene, Google Scholar, and regional databases identified studies reporting patient-level clinical data in individuals with genetically confirmed THAP1 mutations and late-onset disease. Data on age of onset, site of onset, distribution, sex, family history, mutation geste antagoniste were extracted and synthesized descriptively. Twenty-two studies comprising 50 patients met the set inclusion criteria. Cranial dystonia was the most common site of onset (n = 22), followed by cervical (n = 13), while limb onset was uncommon. Most patients presented with segmental distribution (n = 27), followed by focal (n = 20), and only 3 cases demonstrated generalized involvement. The majority of cases were sporadic (37/50). Associated clinical features and geste antagoniste were infrequently and inconsistently reported across studies. We additionally present a Filipina with late-onset focal lower limb dystonia, further highlighting an atypical pattern of limb onset. Collectively, these findings suggest that late-onset THAP1-associated dystonia may exhibit a phenotype distinct from classical early-onset presentations characterized by cranial and cervical predominance, segmental distribution, and frequent sporadic occurrence. Recognition of this broader phenotypic spectrum may facilitate consideration of genetic etiologies in adult-onset dystonia, even in the absence of a family history.

Diurnal variation in antipsychotic-associated acute dystonia: A retrospective cohort study.

Introduction Kratom (Mitragyna speciosa) has traditionally been used in Thailand; however, it was illegal. Following decades of prohibition, kratom was removed from Thailand’s list of narcotics on 24 August 2021, effectively legalizing its use. This study aims to describe the frequency, clinical characteristics, and trends of kratom-related poison center calls before and after legalization. Methods We conducted a retrospective review of data from the Ramathibodi Poison Center covering three 6-month periods: 24th of August, 2020 to 23rd of February, 2021; 24th of February, 2021 to the 23rd of August, 2021; and the 24th of August, 2021 to the 23rd of February, 2022. Patients with confirmed kratom exposure were included. Results Overall, kratom exposure-related phone calls involved 173 cases: 39, 38, and 96 cases in the 1st, 2nd, and 3rd periods, respectively. The mean and median ages of all patients were 29 years (SD 14.1 years) and 25 years (IQR 19–38 years), respectively. Most cases (84.4%) involved male patients, while most (∼60%) also co-ingested kratom with other substances. Tachycardia (43.4%) was the most common abnormal vital sign, and palpitations (35.8%) were the most common clinical manifestation. We compared the clinical characteristics of cases among the three periods, revealing no significant differences in age, sex, regions, co-ingestion, or clinical effects. The prevalence of acute dystonia decreased significantly after legalization (12.8%, 18.4%, and 6.3%, P = 0.008). However, cases in the 3rd period were admitted (37.5%) significantly more often than those in the previous two periods (15.8%, 10.3%; P = 0.001). Discussion Kratom-related calls increased by 2.5-fold after legalization, while consultation and hospitalization rates also rose. Most cases involved young males who used kratom with other substances. The types of symptoms reported before and after legalization remained largely consistent, with neurological and cardiovascular effects predominating. However, hospital admissions increased significantly following legalization. Conclusions Following kratom legalization in Thailand, hospital admissions increased significantly. Continued poison center surveillance and regulatory oversight are essential for monitoring evolving patterns of kratom use and associated harms in the post-legalization era.

Glucose transporter type I (Glut1) deficiency syndrome (Glut1DS) is associated with paroxysmal exertion-induced dystonia (PED). Episodes are published as brief, lasting 20 to 30 minutes. Increasingly, Glut1DS patients report prolonged PED of more than 1 hour duration. In a cohort of 60 Glut1DS patients seen in our institution within a 4-year period, a total of 26/60 patients (43%) on ketogenic dietary therapy (KDT) experienced PED. In 18/26 patients (30%), episodes lasted less than 1 hour as previously described. In 8/26 patients (13%), prolonged episodes lasted more than 1 hour up to 1 day despite adequate dietary treatment. We conclude that PED is common in Glut1DS starting in late childhood despite adequate treatment with KDT. Prolonged PED in Glut1DS occurs in a subset of patients, also unresponsive to KDT, and represents a substantial burden to patients and families.

KMT2B-related dystonia (DYT-28) is a recently recognized cause of early-onset generalized dystonia. Pallidal deep brain stimulation (GPi-DBS) is considered the preferred surgical treatment; however, access, cost, and hardware-related concerns may limit its feasibility, especially in children from resource-constrained settings. Ablative procedures have been rarely reported in this genetic subtype. We report a 9-year-old boy with genetically confirmed KMT2B-related generalized dystonia who underwent simultaneous bilateral radiofrequency pallidotomy. The child had severe, progressive, medically refractory dystonia with a preoperative Burke-Fahn-Marsden Dystonia Rating Scale movement score (BFMDRS-M) of 88. Postoperatively, there was a sustained improvement in dystonia with BFMDRS-M improving to 72 immediately and to 60 at follow-up. Transient hypophonia was the only noted complication and resolved within 1 month. Results remain stable at 18-month follow-up. This case represents the first reported pediatric bilateral pallidotomy for DYT-28 dystonia. Radiofrequency pallidotomy may be a viable alternative in selected children when DBS is not feasible. Longer follow-up and larger studies are required to establish long-term efficacy and safety.

Attentional or Non-Tactile Sensory Tricks in Idiopathic Cervical Dystonia: A Phenomenological Observation.

Deep brain stimulation (DBS) for dystonia is effective but programming optimisation can take months. Local field potentials (LFPs) recorded by the Medtronic Percept device may provide biomarkers to guide stimulation. This study will prospectively evaluate whether chronic LFP profiles correlate with clinical outcomes and can inform DBS programming strategies. LFP-DYT is a single-centre, multi-phase observational study at Newcastle upon Tyne National Health Service (NHS) Foundation Trust. An internal pilot (Cohort 1) will refine recording workflows, followed by Cohort 2 (traditional programming with LFP recordings) and Cohort 3 (LFP-informed programming). 20-25 adults with primary dystonia undergoing globus pallidus internus DBS will be recruited. The study combines chronic LFP sensing with neurophysiology (electromyography, electroencephalography), motor inhibition testing (stop-signal reaction time), patient-reported outcomes and wearable sensor monitoring (STAT-ON) to provide a comprehensive multi-modal assessment framework. reproducibility of alpha-theta frequency LFP peaks and concordance with optimal stimulation site. Secondary outcomes include stimulation and medication effects on LFP profiles, clinical improvement (Toronto Western Spasmodic Torticollis Rating Scale-2 (TWSTRS-2), Burke-Fahn-Marsden Dystonia Rating Scale (BFMDRS)) and beta-band activity as a marker of stimulation-related bradykinesia. Analyses will be descriptive and exploratory. Feasibility outcomes, including recruitment rates, retention and data completeness, will inform design and power calculations for future multi-centre trials. The study has NHS Research Ethics Committee approval from the East Midlands-Derby Research Ethics Committee (REC reference: 24/EM/0246; IRAS ID: 337426). All participants will provide informed consent. Data will be pseudonymised and stored on secure NHS servers. Results will be disseminated via peer-reviewed publications, conferences and participant summaries. De-identified data and analysis code will be available on reasonable request. NCT07309133.

Drug-induced acute dystonia is an adverse drug reaction that is concerning in pediatric patients but resolves rapidly with appropriate treatment. In children, data on risky drugs, clinical patterns, and the management of dystonia in the emergency department are limited. This study aimed to evaluate the demographic and clinical findings and treatment outcomes of children presenting to the pediatric emergency department with drug-induced acute dystonia. This retrospective observational study includes children aged 1 month to 18 years who were diagnosed with acute dystonia in a tertiary pediatric emergency department between October 2022 and March 2025. The diagnosis was made by a pediatric emergency subspecialist based on clinical findings. Patients were classified according to clinical phenotype as focal/segmental dystonia (group I) and multifocal/generalized dystonia (group II). Demographic data, drug exposures, clinical characteristics, and treatment responses were analyzed. A total of 79 patients were included in the study. The median age was 11 years (IQR: 7 to 16) in group I and 10 years (IQR: 6 to 16) in group II. The most commonly associated drug groups were antipsychotics (55.6%), antiemetics (26.6%), and psychostimulants (20.3%). Focal dystonia is the most common clinical pattern, affecting the head and neck muscles in 61% of cases. The use of metoclopramide was significantly higher in group I (OR: 0.21; 95% CI: 0.04-0.99). All patients were treated with parenteral biperiden. Antipsychotics and antiemetics are the main triggers of drug-induced acute dystonia in children. Dystonia usually appears within the first 72 hours after starting the drug. It can develop even at therapeutic doses. Dystonias associated with antiemetic drugs often show focal or segmental distribution. Parenteral biperiden is a fast and effective treatment option. Acute dystonia can mimic serious etiologies in the emergency department. Obtaining a detailed drug history can facilitate the diagnostic process.

L-DOPA-induced dyskinesia is attributed to opposite activity changes mediated by D1 and D2 dopamine receptors in the two striatal output pathways. Whereas the causal role of direct-pathway D1 receptors is well established, the specific involvement of indirect-pathway D2 receptors in dopaminergic dyskinesias has remained elusive. We used conditional knockout approaches in mice to determine whether indirect-pathway D2 receptors causally contribute to dyskinetic and dystonic responses to dopaminergic agents. Studies were conducted in mice with unilateral 6-hydroxydopamine lesions of the nigrostriatal pathway receiving subchronic treatments with L-DOPA or D2/D1-selective agonists. A conditional knockout of indirect-pathway D2 receptors was produced either through the entire striatum (double-transgenic Adora2a-Cre/Drd2loxP/loxP mice) or selectively in the dopamine-denervated dorsal striatum (proenkephalin promoter-driven Cre vector delivery to Drd2loxP/loxP mice). The severity of L-DOPA-induced abnormal involuntary movements and dystonia was halved in both knockout models compared with control mice, whereas the treatment effect on normal motor behaviors was either not reduced or improved. All dyskinetic and dystonic features induced by the D2-selective receptor agonist sumanirole were completely abolished, whereas those induced by the D1-class agonist SKF38393 were largely unaffected. Using phosphorylated ribosomal protein S6 as an activity marker, we detected a treatment-induced recruitment of prototypical parvalbumin-positive neurons in the external globus pallidus (a target of indirect-pathway projections). This effect was inhibited in both knockout models. We provide experimental evidence that indirect-pathway D2 receptors significantly contribute to the expression of dyskinesia during L-DOPA treatment and mediate D2 agonist-dependent dystonic features. © 2026 The Author(s). Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.

Task-specific orofacial tremor is a rare condition in which rhythmic oscillations of orofacial muscles occur during specific actions. Drinking tremor represents a recurrent pattern in isolated reports, although its phenomenology and underlying mechanisms remain incompletely defined. We report three cases of orofacial drinking tremor, each showing a different pattern. Differences involved the distribution of orofacial muscle activity and the presence of additional signs, including tremor in other body regions or subtle dystonic postures. Variability in task dependence, posture sensitivity, and sensory modulation contributed to the heterogeneity of these presentations. Published reports describe a spectrum of orofacial drinking tremors, ranging from strictly task-specific patterns to mixed task- and position-dependent presentations. Some patients exhibit subtle dystonic features, whereas others show no clear additional neurological signs. Electrophysiology typically demonstrates regular 5-8 Hz rhythmic discharges in the orofacial muscles. Systemic pharmacological therapies offer limited benefit, whereas botulinum toxin remains the most effective option. Current evidence suggests that orofacial drinking tremor does not represent a single clinical entity. An approach integrating detailed phenomenological characterization with plausible pathophysiological mechanisms may improve diagnostic interpretation and guide individualized management strategies.

The clinical evidence for antipsychotic (AP) therapeutic drug monitoring (TDM) in evaluating AP-related movement disorders and cardiometabolic side-effects remains inconsistent. This study evaluates how AP plasma concentrations associate with movement disorders and cardiometabolic side-effects over time, and compares its predictive value to prescription dose in first-episode psychosis (FEP) patients. We included 200 remitted FEP patients from the HAMLETT trial. AP plasma concentrations were standardized using robust z-scores to accommodate different AP types. The St. Hans Rating Scale and Barnes Akathisia Rating Scale assessed movement disorders. Cardiometabolic indices included body mass index, waist circumference, blood pressure, glucose, triglycerides, and cholesterol. We evaluated longitudinal associations between plasma concentrations, movement disorders and cardiometabolic side-effects using two-part and linear mixed-effects models, and compared its predictive value to prescription dose using Bayesian Information Criterion (ΔBIC). Over a median 6-month follow-up (range = 0-48), AP plasma concentrations were positively associated with odds for parkinsonism (OR = 1.81, 95 % CI 1.27, 2.57, p = 0.001). No associations were found with tardive dyskinesia, akathisia, tardive dystonia, or cardiometabolic indices. AP plasma concentrations predicted parkinsonism better than prescription dose (ΔBIC = -2.95), but showed lower predictive value for waist circumference (ΔBIC = 3.22), total cholesterol (ΔBIC = 3.70), low-density-lipoprotein cholesterol (ΔBIC = 2.14) and non-high-density-lipoprotein cholesterol (ΔBIC = 5.46). These findings suggest that in remitted FEP patients, AP TDM may be more useful than dose in evaluating parkinsonism, likely because plasma concentrations more closely reflect free drugs at striatal dopamine receptors, but it does not appear useful for cardiometabolic side-effects.

DYT-AOPEP: A case series from India expanding the clinical and genetic spectrum.

Clinical, practical, and psychosocial challenges of living with glucose transporter type 1 deficiency syndrome.

Background: Functional neurosurgery, particularly Deep Brain Stimulation (DBS) and ablative procedures like pallidotomy and thalamotomy, has emerged as a powerful tool in the treatment of medically refractory movement disorders. However, its application in low-resource countries like Nepal is limited. This study presents our early experience with surgical management of movement disorders at Bir Hospital using DBS and lesioning techniques. Methods: This is a prospective study from the period of April 2024 to June 2025 at the National Neurosurgical Referral Center (NNRC), National Academy of Medical Sciences (NAMS) Bir Hospital. Patients with advanced Parkinson’s disease or primary dystonia underwent surgical intervention. Four patients received bilateral Globus Pallidus internus (GPi) DBS, one patient received bilateral subthalamic nucleus(STN)DBS and three underwent unilateral radiofrequency pallidotomy. All surgeries were performed under local anesthesia except for IPG placement, which was done under general anesthesia. Patients were evaluated for improvement in tremor, rigidity, camptocormia, and dystonia. Clinical outcomes and complications were assessed over a follow-up period of up to one year. Results: All patients demonstrated significant clinical improvement in motor symptoms postoperatively. Four patients with over 1-year follow-up maintained sustained benefits. The remaining four, with early 1 month follow-up, also showed encouraging results. The outcomes between DBS and pallidotomy groups were clinically comparable. All procedures were completed safely with no perioperative complications. Cost remains the major barrier to widespread DBS adoption in Nepal. Conclusion: Both DBS and pallidotomy are effective and safe for the treatment of movement disorders. In resource-constrained settings, lesioning offers a viable and affordable alternative. Early surgical referral and government subsidy for DBS can improve access and patient outcomes in Nepal.

When Not a Seizure: Risperidone-Induced Acute Dystonia Mimicking Seizures in a Preschool Child

Drug-induced dystonia and dyskinesia are associated with increased all-cause mortality, with limited data on cause-specific mortality. We aim to confirm mortality risk and cause-specific mortality in drug-induced acute dystonia or tardive dyskinesia. From Taiwan's National Health Insurance Database (2015-2021), we identified adults with ≥2 psychiatrist- or neurologist-confirmed diagnoses of drug-induced acute dystonia or tardive dyskinesia, and created 1:4 age- and sex-matched population controls and an unaffected sibling cohort. Outcomes included all-cause, natural-cause, and unnatural-cause mortality expressed as hazard ratios (HRs) with 95% confidence intervals (CIs). Multivariable Cox models were adjusted for sex, age, urbanization, socioeconomic status, and comorbidities. A total of 2862 patients and 11 448 matched controls were identified. Mean age was 64.6years, 67.2% female, mean follow-up duration was 4.5years. Drug-induced acute dystonia or tardive dyskinesia was associated with significant excess risk of all-cause (HR = 1.51, 95% CI 1.36-1.67), natural-cause (1.39, 1.25-1.55), and unnatural-cause (3.67, 2.42-5.54) mortality. For natural-cause mortality, mortality risk was elevated for endocrine, nutritional, and metabolic diseases; mental and behavioral disorders; nervous, circulatory, and respiratory system diseases; but reduced for neoplasms. For unnatural-cause mortality, both accidents and suicides revealed higher mortality risks. Results were similar across age groups and ten psychiatric comorbidities. Sex subgroup analysis revealed higher suicide mortality risk in females than males. Drug-induced acute dystonia and tardive dyskinesia are associated with elevated all-cause, natural-cause, unnatural-cause, and cause-specific mortalities, highlighting the need for targeted interventions to prevent these specific causes of deaths.

A woman with complex psychiatric illness and substance use disorder presented with nausea, vomiting, and episodes of oculogyric crisis. A medication review suggested drug-induced acute dystonia, likely triggered by metoclopramide. Other symptoms were possibly related to cumulative anticholinergic effects. Fluoxetine, a potent CYP2D6 inhibitor, may have increased exposure to metoclopramide and promethazine. This case report demonstrates that pharmacological insight and deprescribing can improve symptoms and support rational pharmacotherapy in vulnerable psychiatric patients.

Opisthotonus: Revisiting a classic movement disorder.