An Evidence-Based Update on Anticholinergic Use for Drug-Induced Movement Disorders.

Drug-induced movement disorders (DIMDs) are associated with use of dopamine receptor blocking agents (DRBAs), including antipsychotics. The most common forms are drug-induced parkinsonism (DIP), dystonia, akathisia, and tardive dyskinesia (TD). Although rare, neuroleptic malignant syndrome (NMS) is a potentially life-threatening consequence of DRBA exposure. Recommendations for anticholinergic use in patients with DIMDs were developed on the basis of a roundtable discussion with healthcare professionals with extensive expertise in DIMD management, along with a comprehensive literature review. The roundtable agreed that "extrapyramidal symptoms" is a non-specific term that encompasses a range of abnormal movements. As such, it contributes to a misconception that all DIMDs can be treated in the same way, potentially leading to the misuse and overprescribing of anticholinergics. DIMDs are neurobiologically and clinically distinct, with different treatment paradigms and varying levels of evidence for anticholinergic use. Whereas evidence indicates anticholinergics can be effective for DIP and dystonia, they are not recommended for TD, akathisia, or NMS; nor are they supported for preventing DIMDs except in individuals at high risk for acute dystonia. Anticholinergics may induce serious peripheral adverse effects (e.g., urinary retention) and central effects (e.g., impaired cognition), all of which can be highly concerning especially in older adults. Appropriate use of anticholinergics therefore requires careful consideration of the evidence for efficacy (e.g., supportive for DIP but not TD) and the risks for serious adverse events. If used, anticholinergic medications should be prescribed at the lowest effective dose and for limited periods of time. When discontinued, they should be tapered gradually.

Antipsychotic-induced acute laryngeal dystonia: A systematic review of case reports.

Acute laryngeal dystonia (ALD) is a rare but potentially life-threatening complication of both first-generation (FGA) and second-generation (SGA) antipsychotic medication. Delays in diagnosis and treatment have been associated with mortality. We carried out a systematic review of antipsychotic-induced acute laryngeal dystonia using the databases Ovid MEDLINE, PubMed, CINAHL, and EMBASE. Search terms included: (antipsychotic* OR antipsychotic-induced OR neuroleptic* OR neuroleptic-induced) AND (laryngeal dystonia* OR laryngo-pharyngeal dystonia* OR laryngospasm OR laryngeal spasm OR dystonic reaction* OR extrapyramidal reaction*) where * specified plural forms of the relevant word. Forty articles (describing 45 cases) met eligibility criteria. ALD occurred with both first- and second- generation antipsychotics but was more commonly reported in FGAs. ALD occurred in association with low, moderate and high doses (within the usual dose ranges of both high and low potency agents). Young males appeared to be most at risk of antipsychotic-induced ALD, especially those treated with high potency agents. Anticholinergic medication (including antihistamines with anticholinergic properties) usually provided rapid and effective relief, especially if administered parentally. Vigilance is indicated for idiosyncratic ALD emergence when initiating, or increasing the dose of, an antipsychotic medication. Rapid treatment with an anticholinergic medication is recommended to prevent adverse outcomes.

Acute Dystonic Reaction After Propofol Administration: A Pediatric Case Report.

We present a case of a 12-year-old female with a history of infantile spasms who developed a propofol-associated acute dystonic reaction after emergence from general anesthesia for foot surgery. Uniquely, the patient's postoperative symptoms of an acute dystonic reaction were refractory to standard treatment with anticholinergics but were successfully treated with corticosteroids. The absence of any dystonic symptoms following subsequent foot surgery under general anesthesia without propofol supported a propofol-associated etiology. This case may contribute to a better understanding of the underlying mechanisms of propofol-associated acute dystonic reactions and adds a possible new treatment option.

The Extrapyramidal Symptom Rating Scale and Its Abbreviated Version: A Critical Review of Clinimetric Properties.

BACKGROUND: The Extrapyramidal Symptom Rating Scale - Abbreviated (ESRS-A) is an abbreviated version of the Extrapyramidal Symptom Rating Scale (ESRS) with instructions, definitions, and a semi-structured interview that follows clinimetric concepts of measuring clinical symptoms. Similar to the ESRS, the ESRS-A was developed to assess four types of drug-induced movement disorders (DIMD): parkinsonism, akathisia, dystonia, and tardive dyskinesia (TD). SUMMARY: The present review of the literature provides the most relevant clinimetric properties displayed by the ESRS and ESRS-A in clinical studies. Comprehensive ESRS-A definitions, official scale, and basic instructions are provided. ESRS inter-rater reliability was evaluated in two pivotal studies and in multicenter international studies. Inter-rater reliability was high for assessing both antipsychotic-induced movement disorders and idiopathic Parkinson's disease. Guidelines were also established for inter-rater reliability and the rater certification processes. The ESRS showed good concurrent validity with 96% agreement between Abnormal Involuntary Movement Scale (AIMS) for TD-defined cases and ESRS-defined cases. Similarly, concurrent validity for ESRS-A total and subscores for parkinsonism, akathisia, dystonia, and dyskinesia ranged from good to very good. The ESRS was particularly sensitive for detecting DIMD-related movement differences following treatment with placebo, antipsychotics, and antiparkinsonian and antidyskinetic medications. ESRS measurement of drug-induced extrapyramidal symptoms was shown to discriminate extrapyramidal symptoms from psychiatric symptoms. KEY MESSAGES: The ESRS and ESRS-A are valid clinimetric indices for measuring DIMD. They can be valuably implemented in clinical research, particularly in trials testing antipsychotic medications, and in clinics to detect the presence, severity, and response to treatment of movement disorders.

Task-specific oromandibular dystonia secondary to chewing Khat (Catha edulis)- A series of 35 cases.

BACKGROUND: The leaves of "Khat" (Catha edulis), an indigenous shrub of Yemen and Arabian Peninsula are habitually chewed by the inhabitants for psychostimulant properties. OBJECTIVE: To describe a unique task specific Oro-mandibular dystonia (OMD) in Yemenese men, with a temporal association with chewing "Khat". METHODS: Multicentric, retrospective analysis (2009-2020) of patients with OMD associated with "Khat" chewing, evaluating clinical features and response to Onabotulinum toxin A. RESULTS: 35 Yemenese men with a negative family history, normal neuroimaging mean age of 44.31(±3.21) years and prolonged (20.31 ± 3.27 years) history of chewing Khat, around 5.16(±0.80) hours/day presented with OMD-20 jaw opening, 13 jaw closing and 2 mixed affecting chewing (n = 6), speech (n = 3), or both (n = 26). Additional lingual dystonia was seen in five. CONCLUSIONS: Chewing of khat is a repetitive task involving the jaw musculature and may be one of the causative factors of this task specific OMD. Recognition can prevent disability in these regions.

Dexmedetomidine at Home for Intractable Dystonia and Insomnia in Children With Special Needs: A Case Series.

BACKGROUND: We know that syndromic conditions and severe chronic diseases can be associated with symptoms that may interfere with sleep, significantly impacting the life quality of children and caregivers. Drugs commonly used in treating insomnia, such as melatonin, benzodiazepines, niaprazine, and antihistamines, are often either ineffective or associated with adverse effects, requiring new therapeutic perspectives. Dexmedetomidine is a selective alpha-2 agonist with hypnotic and anxiolytic effects, which, by stimulating alpha-2 adrenergic receptors in the locus coeruleus, induces sleep comparable to stages 2-3 of the non-REM phase without substantially affecting the respiratory drive during sedation. Its use has already been extensively described in pediatric intensive care or procedural sedation literature. In 2018, the Italian Medicines Agency (Agenzia Italiana Del Farmaco AIFA) authorized the off-label use of dexmedetomidine outside of intensive care in Children undergoing palliative treatment to control distressing symptoms related to pathology and refractory sleep disorders, and the literature reported cases of children who received dexmedetomidine at home. OBJECTIVE: Our study aims to describe the home use of dexmedetomidine in children with insomnia or intractable dystonic states. MEASURES: We conducted a retrospective analysis through a questionnaire addressed to 12 Italian pediatric palliative care centers regarding the home use of dexmedetomidine in sleep disorders and intractable dystonic states. INTERVENTION: We collected a case series of 9 children treated with dexmedetomidine at home, 8 via intranasal and 1 via intravenous route. All children received the first drug administration in the hospital or hospice during a dedicated admission, under close monitoring of vital signs parameters for 72 hours (3 days, range 2-7 days). After discharge, the potential side effects of the drug were explained to the patient's families, and, once informed consent was obtained, the home administration of dexmedetomidine continued, with follow-up by the palliative care team. At home, dexmedetomidine was administered for 3000 days (minimum 1 month, maximum 36 months). The first patient was treated for 1095 days, from 2019 to 2021 (discontinued due to underlying condition-related death). OUTCOMES: All patients observed a persistent benefit from the treatment on symptoms, and none of them discontinued dexmedetomidine administration due to drug-related adverse effects or perceived lack of therapeutic efficacy. CONCLUSIONS: Therefore, its use at home may represent a promising therapeutic approach for intractable sleep disorders or dystonic states in pediatric palliative care children. Further studies are needed to confirm our results.

The pluripotential evolution and journey of Botox (onabotulinumtoxinA).

Clinical use of onabotulinumtoxinA evolved based on strategic, hypothesis-driven applications, as well as serendipitous observations by physicians and patients. The success of onabotulinumtoxinA in blepharospasm and strabismus led to its study in other head and neck dystonias, followed by limb dystonia, tremor, and spasticity. The aesthetic use of onabotulinumtoxinA followed initial reports from patients of improved facial lines after injections for facial dystonias and hemifacial spasm. Although patients with dystonias and spasticity regularly reported that their local pain improved after injections, onabotulinumtoxinA was not systematically explored for chronic migraine until patients began reporting headache improvements following aesthetic injections. Clinicians began assessing onabotulinumtoxinA for facial sweating and hyperhidrosis based on its inhibition of acetylcholine from sympathetic cholinergic nerves. Yet another line of research grew out of injections for laryngeal dystonia, whereby clinicians began to explore other sphincters in the gastrointestinal tract and eventually to treatment of pelvic sphincters; many of these sphincters are innervated by autonomic nerves. Additional investigations in other autonomically mediated conditions were conducted, including overactive bladder and neurogenic detrusor overactivity, achalasia, obesity, and postoperative atrial fibrillation. The study of onabotulinumtoxinA for depression also grew out of the cosmetic experience and the observation that relaxing facial muscle contractions associated with negative emotions may improve mood. For approved indications, the safety profile of onabotulinumtoxinA has been demonstrated in the formal development programs and post-marketing reports. Over time, evidence has accumulated suggesting clinical manifestations of systemic effects, albeit uncommon, particularly with high doses and in vulnerable populations. Although onabotulinumtoxinA is approved for approximately 26 indications across multiple local regions, there are 15 primary indication uses that have been approved in most regions, including the United States, Europe, South America, and Asia. This review describes many uses for which AbbVie has not sought and/or received regulatory approval and are mentioned for historical context only.

Assessment of Patients Receiving Short-Interval Botulinum Toxin Chemodenervation Treatment for Laryngeal Dystonia and Essential Tremor of the Vocal Tract.

Importance: The gold-standard treatment for laryngeal dystonia (LD) and essential tremor of the vocal tract (ETVT) is botulinum toxin (BoNT) chemodenervation. Although safe and effective, it is not curative, and periodic injections are required. Some medical insurance companies only cover injections at a 3-month interval, though some patients benefit from injections more frequently. Objective: To determine the proportion and characteristics of patients who receive BoNT chemodenervation treatment in intervals shorter than 90 days. Design, Setting, and Participants: This retrospective cohort study across 3 quaternary care neurolaryngology specialty practices in Washington and California recruited patients who underwent at least 4 consecutive laryngeal BoNT injections for LD and/or ETVT in the past 5 years. Data were collected from March through June 2022 and analyzed from June through December 2022. Exposure: Laryngeal BoNT treatment. Main Outcomes and Measures: Biodemographic and clinical variables, injection characteristics, evolution during the 3 interinjection intervals, and lifetime laryngeal BoNT treatment data were collected from patient medical records. Logistic regression was used to assess association to the short-interval outcome, defined as an average injection interval shorter than 90 days. Results: Of 255 patients included from the 3 institutions, 189 (74.1%) were female, and the mean (SD) age was 62.7 (14.3) years. The predominant diagnosis was adductor LD (n = 199 [78.0%]), followed by adductor dystonic voice tremor (n = 26 [10.2%]) and ETVT (n = 13 [5.1%]). Seventy patients (27.5%) received short-interval injections (<90 days). The short-interval group was younger than the long-interval group (≥90 days), with a mean (SD) age of 58.6 (15.5) years and 64.2 (13.5) years, respectively, and a mean difference of -5.7 years (95% CI, -9.6 to -1.8 years). There were no patient-related differences between the short- and long-interval groups in terms of sex, employment status, or diagnosis. Conclusions and Relevance: This cohort study demonstrated that while insurance companies often mandate a 3-month or greater interval for BoNT chemodenervation financial coverage, there is a considerable subset of patients with LD and ETVT who receive short-interval treatment to optimize their vocal function. Short-interval chemodenervation injections demonstrate a similar adverse effect profile and do not appear to predispose to resistance through antibody formation.

Attainment of personal goals in the first year of intrathecal baclofen treatment in dyskinetic cerebral palsy: a prospective cohort study.

PURPOSE: To assess attainment of individual treatment goals one year after intrathecal baclofen (ITB) pump implantation in individuals with dyskinetic cerebral palsy (CP). MATERIALS AND METHODS: A multi-center prospective cohort study was conducted including 34 non-walking individuals with severe dyskinetic CP, classified as Gross Motor Function Classification System (GMFCS) IV/V, aged 4-24 years, 12 months after pump implantation. The main outcome measure was Goal Attainment Scaling (GAS). Predictors of GAS results were analyzed. Complications were registered systematically. RESULTS: Seventy-one percent of individuals with dyskinetic CP fully achieved one or more treatment goals. One or more treatment goals were partially achieved in 97% of individuals. Two factors were found to be associated with attainment of goals: Dyskinesia Impairment Scale (DIS) score at baseline and the difference in pain score between baseline and follow-up. These two variables explain 30% of the variance in the outcome. CONCLUSIONS: Intrathecal baclofen is effective in achieving individual treatment goals in children and young adults with dyskinetic CP after nine to 12 months of ITB treatment. A positive outcome on treatment goals is, for a small part, associated with higher severity of dystonia at baseline and with improvement of pain during treatment. CLINICAL TRIAL REGISTRATION NUMBER: Dutch Trial Register, number NTR3642.Implications for rehabilitationIntrathecal baclofen treatment is effective in attainment of personal treatment goals, one year after pump implantation in patients with dyskinetic cerebral palsy.A positive outcome on treatment goals is, for a small part, related to higher severity of dystonia at the start and on improvement of pain during treatment.

Tablet-based patient educational interventions in care and management of complex movement disorders.

BACKGROUND: Patient education is an essential part of management of complex, disabling neurological disorders. Mobile web-based educational materials provide a novel and potentially valuable means to communicate clinical information that can aid in both medical management and rehabilitation. AIMS: We, therefore, evaluated an educational tablet-based intervention in three patient cohorts regarding the following topics: Parkinson's disease (PD) medications, dystonia and botulinum toxin treatment. METHODS: A total of 50 subjects with PD, 32 with dystonia and 61 receiving botulinum toxin treatment for movement disorders or sialorrhoea were enrolled. Participants in each cohort completed a specific educational module at the time of their regularly scheduled clinic visit, comprising slides, in addition to pre- and post-module quizzes and a satisfaction survey. Additionally, participants in the dystonia and botulinum toxin modules were given a follow-up test at their 3- or 6-month clinical treatment visit. RESULTS: There were 143 participants with 50 completing the PD module, 32 completing the dystonia module and 61 completing the botulinum toxin module. All three groups demonstrated significant improvement in knowledge of module content between their pre- and post-module test scores (PD: p=.0001, dystonia: p<.0001 and botulinum toxin: p=.008), and those who took the dystonia module maintained significant improvement at either a 3- or 6-month follow up compared to pre-module (p <.0001). CONCLUSIONS: Tablet-based teaching modules are an effective means of communicating key concepts to patients. This study supports their use for improving patient understanding that can support lifelong approaches to managing disabling, neurological conditions.Implication for RehabilitationTablet-based modules are relatively easy to use for enhancing education during clinic visits and can possibly help reduce and maintain disability with chronic conditions like Parkinson's disease and dystonia.Improvements in post-test scores suggested that patient participants were able to retain information from the tablets about their complex and challenging conditions and treatments.Adding patients who are fluent in another language would have made this study more generalizable and future studies exploring educational interventions are warranted to help better tailor interventions to patients with chronic neurologic illnesses to help understand the complex aspects of their medical and rehabilitation therapy.The effect of cognitive changes in neurological conditions and understanding of educational information needs to be further tested.This positive result is especially meaningful during the COVID-19 pandemic when in-person access to both medical and rehabilitative care has been curtailed.

Diphenhydramine induced acute dystonia: a case report.

Acute dystonia has notably been a challenge in the emergency unit. Drug-induced dystonia is reported in a limited number of cases in the literature. Rarely, diphenhydramine was found to be the culprit. We report the case of a 25-year-old female patient who developed an acute dystonic reaction following the administration of 25 mg of intravenous diphenhydramine as a treatment for an allergic reaction. The patient was given 5 mg diazepam, admitted for monitoring, and discharged home. Diphenhydramine-induced acute dystonia is a user drug-induced threatening reaction that warrants further investigation on the metabolism of these drugs and the contributing phenotypes to this adverse reaction.

[Use of central anticholinergics in 2022]. / Utilisation des anticholinergiques centraux en 2022.

Cholinergic antagonists have been used for 60 years in the treatment of movement disorders. Their effect arises from a modulating activity within basal ganglia motor circuitry. Due to diffuse distribution among many organs, anticholinergic medications have numerous adverse effects. Nowadays, the indication of these molecules in the treatment of Parkinson disease is reduced, due to more effective and better tolerated alternatives. Iatrogenic parkinsonism is hardly alleviated by anticholinergics. These medications allow to prevent acute dystonic reactions induced by highly-dosed first generation antipsychotic agents. Once acute dystonia has appeared, parenteral treatment is to be preferred, but oral cholinergic antagonists may be used after the acute phase to prevent relapse. Botulinum toxin is preferred to anticholinergics for focal dystonia. In generalized dystonia, anticholinergic moderately alleviate symptoms.

Les anticholinergiques sont utilisés depuis plus de 60 ans pour traiter les mouvements anormaux. Leur effet thérapeutique provient d'une modulation, via des récepteurs muscariniques, des boucles motrices des noyaux gris centraux. Ce type de traitement a aussi de nombreux effets indésirables en lien avec la large distribution de récepteurs muscariniques dans plusieurs organes. Actuellement, la place de ces molécules est marginale dans le traitement de la maladie de Parkinson en raison d'alternatives plus efficaces et mieux tolérées. Leur efficacité est limitée en cas de parkinsonisme iatrogène. Ils contribuent à la prévention de la dystonie aiguë liée à l'utilisation de neuroleptiques de première génération à fortes doses. Lorsque la dystonie aiguë est présente, une solution parentérale est à privilégier, avec un relais possible par les anticholinergiques par voie orale. En cas de dystonie focale, les injections de toxine botulique sont plus efficaces. En cas de dystonie généralisée, les anticholinergiques ont une efficacité modérée.

Tardive Oromandibular Dystonia Induced by Trazodone: A Clinical Case and Management from the Perspective of the Dental Specialist.

BACKGROUND: Tardive Oromandibular Dystonia is an iatrogenic drug-induced movement form of extrapyramidal symptoms associated primarily with chronic consumption of dopamine receptor blocking agents. Tardive symptoms attributable to selective serotonin reuptake inhibitors antidepressants are far less prevalent. CLINICAL CASE: The authors will present a clinical case and management, from the dental specialist perspective, of a 55-year-old female patient who developed tardive oromandibular dystonia induced by Trazodone prescribed for sleep insomnia. CONCLUSIONS: Trazodone-induced oromandibular dystonia is extremely rare. Early identification and assessment of tardive symptoms are imperative for successful treatment. Trazodone should be prescribed with caution in patients taking other medications with the potential to cause tardive syndromes.

Pathophysiological studies of aging Slc39a14 knockout mice to assess the progression of manganese-induced dystonia-parkinsonism.

Over the last decade, several clinical reports have outlined cases of early-onset manganese (Mn)-induced dystonia-parkinsonism, resulting from loss of function mutations of the Mn transporter gene SLC39A14. Previously, we have performed characterization of the behavioral, neurochemical, and neuropathological changes in 60-day old (PN60) Slc39a14-knockout (KO) murine model of the human disease. Here, we extend our studies to aging Slc39a14-KO mice to assess the progression of the disease. Our results indicate that 365-day old (PN365) Slc39a14-KO mice present with markedly elevated blood and brain Mn levels, similar to those found in the PN60 mice and representative of the human cases of the disease. Furthermore, aging Slc39a14-KO mice consistently manifest a hypoactive and dystonic behavioral deficits, similar to the PN60 animals, suggesting that the behavioral changes are established early in life without further age-associated deterioration. Neurochemical, neuropathological, and functional assessment of the dopaminergic system of the basal ganglia revealed absence of neurodegenerative changes of dopamine (DA) neurons in the substantia nigra pars compacta (SNc), with no changes in DA or metabolite concentrations in the striatum of Slc39a14-KO mice relative to wildtype (WT). Similar to the PN60 animals, aging Slc39a14-KO mice expressed a marked inhibition of potassium-stimulated DA release in the striatum. Together our findings indicate that the pathophysiological changes observed in the basal ganglia of aging Slc39a14-KO animals are similar to those at PN60 and aging does not have a significant effect on these parameters.