Drug-induced movement disorders

Tips and tricks in tremor treatment

Tremor, whether arising from neurological diseases, other conditions, or medication side effects, significantly impacts patients' lives. Treatment complexities necessitate clear algorithms and strategies. Levodopa remains pivotal for Parkinson's tremor, though response variability exists. Some dopamine agonists offer notable tremor reduction targeting D2 receptors. Propranolol effectively manages essential tremor and essential tremor plus (ET/ET +), sometimes with primidone for added benefits, albeit dose-dependent side effects. As reserve medications anticholinergics and clozapine are used for treatment of parkinsonian tremor, 1-Octanol and certain anticonvulsant drugs for tremor of other orign, especially ET. Therapies such as invasive deep brain stimulation and lesional focused ultrasound serve for resistant cases. A medication review is crucial for all forms of tremor, but it is particularly important if medication may have triggered the tremor. Sensor-based detection and non-drug interventions like wristbands and physical therapy broaden diagnostic and therapeutic horizons, promising future tremor care enhancements. Understanding treatment nuances is a key for tailored tremor management respecting patient needs and tolerability. Successful strategies integrate pharmacological, non-invasive, and technological modalities, aiming for optimal symptom control and improved quality of life.

Pathophysiology, prognosis and treatment of tardive dyskinesia

Tardive dyskinesia (TD), a movement disorder associated with antipsychotics, most frequently affects the lower face and jaw muscles, but can also affect walking, breathing and use of the hands and limbs. Knowledge of TD among physicians may be limited, and the pathophysiology of TD is poorly understood. We conducted this review to summarise the current knowledge surrounding the pathophysiology of TD and present recommendations for prevention and treatment based on a literature search and roundtable discussion attended by psychiatrists in Japan. It has been suggested that dopamine hypersensitivity, damaged gamma-aminobutyric acidergic neurons and/or increased production of reactive oxygen species may contribute to development of TD. Symptoms can profoundly affect everyday life; patients who develop TD have poorer prognoses, worse health-related quality of life, greater social withdrawal and higher mortality than patients without TD. Traditional treatment options include dietary supplements, although evidence for their effectiveness is low. Among pharmaceutical interventions, there is moderate evidence that switching to the second-generation antipsychotic clozapine, which has a lower affinity for dopamine D2 receptors than other antipsychotics, may improve symptoms. Vesicular monoamine transporter 2 (VMAT-2) inhibitors, which oppose the increased dopaminergic activity associated with prolonged antipsychotic use by interfering with dopamine uptake and storage, have the strongest evidence for efficacy. VMAT-2 inhibitors are approved in the United States for the treatment of TD, and the first VMAT-2 inhibitor was approved in Japan for this indication in March 2022. Most guidelines recommend treating TD by first reducing the dose of antipsychotics or switching to clozapine or other second-generation antipsychotics, which have a lower association with TD than first-generation antipsychotics. We recommend focusing on prevention and monitoring for TD when prescribing antipsychotics, given that TD is often irreversible. Physicians should treat with antipsychotics only when necessary and at the lowest effective dose, and frequently monitor for TD symptoms.

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Plain Language Summary (In Japanese).

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Visual Summary (In Japanese).

Research trends and frontiers in exercise for movement disorders: A bibliometric analysis of global research from 2010 to 2021

Objective

To conduct a bibliometric analysis of trends and frontiers on exercise-based non-pharmacological treatments for movement disorders published between 2010 and 2021.

Methods

The Web of Science (WOS) Core Collection database was searched for articles published between 2010 and 2021. The CiteSpace software was used for in-depth analysis of the countries, institutions, journals, and collaboration networks among authors and their types of articles, developmental directions, references, and hot keywords of published articles.

Results

A total of 2,626 published articles were retrieved by search formula and included in the analysis. The number of publications fluctuated during this period, with 96 countries, 3,058 institutions, and 886 academic journals having published articles in this area, with subject classifications that focused on Clinical Neurology and Neurosciences. The United States has maintained its dominant and most influential position in exercise-based non-pharmacological research on movement disorders. Among research institutions and journals, the League of European Research Universities and Movement Disorders journals published the highest number of academic articles. In the last five years, the hot research topics by burst keyword analysis, are focused on treatments, research advances, and clinical treatments.

Conclusion

Research on exercise-based non-pharmacological treatments for movement disorders is generally on the rise from 2010 to 2021. The bibliometric analysis of this area will help provide potential collaborations among researchers, frontiers, and directions for development.

Antipsychotic-induced movement disorders: integrative review

Objective: To identify movement disorders induced by antipsychotics. Methods: We selected clinical trials from MEDLINE and LILACS databases without publication date restriction. Studies of antipsychotics as a pharmacological intervention, compared or not to other interventions were included (combined treatments were not included). The primary outcome was movement disorders. Two independent reviewers analyzed the studies and summarized them in an electronic spreadsheet. We assessed the quality of the selected studies using the PEDro scale. Results: Five studies were included in this review. In these studies, it was possible to identify the main psychiatric symptoms and their severity, as well as dyskinetic movements. When a reduction in dyskinetic movements was observed in treatments with both atypical and typical antipsychotics, there were adverse effects. Those included excessive sedation, loss of body mass, vomiting, and leukocytopenia. Conclusion: This study verified the findings in literature on the effects of antipsychotics, including the type of medication, dosage, and form of administration, as well as instruments used to assess the outcome related to movement disorders. It was not possible to determine the best therapeutic dose for managing the disorders due to the significant distinction in dosages and medications. All five studies had some effect related to the drug use or its withdrawal.

Comparison of Extrapyramidal Symptoms Among Outpatients With Schizophrenia on Long-Acting Injectable Antipsychotics

BACKGROUND

Extrapyramidal symptoms (EPSs) are adverse effects of antipsychotics. Different risks of EPSs have been attributed to the 3 classes of antipsychotics. This study aimed to assess EPS in a clinical sample of schizophrenia patients who are on LAI and compare the severity of EPSs among the following 3 antipsychotic groups: (1) partial agonist, (2) second-generation antipsychotics, and (3) first-generation antipsychotics.

METHODS

Ninety-two patients were recruited from the Schizophrenia Program Injection Clinic. Using the Extrapyramidal Symptom Rating Scale (ESRS), severity of EPS was assessed and information regarding factors associated with risk of EPS, including coprescriptions, comorbidities, and demographics, was obtained from medical charts. Group differences in ESRS scores and subscores were analyzed using 1-way analyses of variances.

RESULTS

Among the 3 groups, there was no significant difference in total ESRS scores and subscores. Risperidone was associated with higher ESRS scores when compared with paliperidone, aripiprazole, and flupenthixol. Doses above maximum were commonly used in the paliperidone group, and there was no significant difference in total ESRS scores between the low, average, or above-maximum doses of paliperidone.

CONCLUSIONS

Our results demonstrated a comparative risk of EPS across all 3 antipsychotic classes. Risperidone was associated with more EPS compared with other medications. A higher threshold for the "maximum dose" of paliperidone could be considered and higher doses used with the same cautions as low-average doses.

Abnormal Movement Following Transcobalamin II Deficiency Treatment Responding to Clonazepam: A Case Report

Transcobalamin II (TCII) is a transporter protein that facilitates cobalamin release from the bloodstream to the cell. Deficiency in TCII is an autosomal recessive disorder caused by a mutation in the TCN2 gene. Treatment with intramuscular injection of hydroxocobalamin is greatly effective in improving the symptoms of this disorder. However, abnormal involuntary movements can occur and have been reported in patients with cobalamin deficiency caused by nutritional deficiency. Though, it is rarely associated with the treatment of hereditary TCII deficiency. Here, we report such a case, aiming to alert practitioners treating hereditary TCII deficiency. A 2-year-old boy born to a consanguineous parents presented with failure to thrive, recurrent infection, and pancytopenia. His condition deteriorated rapidly, and his investigation was remarkable for pancytopenia, elevated methylmalonic acid, and myelodysplastic changes in the bone marrow. A flash whole-exome sequence confirmed the diagnosis of TCII deficiency. The patient began treatment with IM hydroxocobalamin, and on the second day, he developed an abnormal involuntary movement that was abated by clonazepam. Abnormal nonepileptic movements following IM hydroxocobalamin in a patient with TCII deficiency shows a remarkable response to clonazepam.

Metoclopramide-Induced Acute Dystonia: Data From a Pediatric Emergency Unit

OBJECTIVES

Metoclopramide is a commonly used medication in pediatric practice, and dystonia is a common adverse effect of it. The present study aims to evaluate the clinical characteristics of metoclopramide-induced acute dystonic reactions (MIADRs) in pediatric patients admitted to the pediatric emergency unit.

METHODS

Twenty-eight patients were admitted with MIADRs between June 2004 and April 2016; they were enrolled into the study retrospectively.

RESULTS

The study group was composed of 13 females and 15 males with the mean ± SD age of the females higher than that of the males, 12.3 ± 4.5 and 7.8 ± 4.3 years, respectively. Only 9 (32.1%) of the patients were diagnosed as MIADRs at the time of admission. Seventeen patients (60.7%) received over the recommended daily dose of metoclopramide. Dystonia was focal in most of the patients, with the most affected parts consisting of the neck, eyes, and orolingual regions. In 9 of the patients, the dystonia was episodic in nature. Pharmacological treatment was used for 18 patients. No patients died, and none suffered long-term injury related to MIADRs.

CONCLUSIONS

Metoclopramide administration may be associated with the occurrence of acute dystonic reaction. Metoclopramide-induced acute dystonic reactions may be misdiagnosed, so detailed medical history gathering and a high index of suspicion are warranted. Our data suggest that MIADRs may be dose related and that there may be age- and sex-related differences in the epidemiology of MIADRs.

Acute pharmacogenetic dystonic reactions in a family with the CYP2D6 *41 allele: a case report

Background

Dystonia is a known neurological complication of certain medications; however, the mechanism behind such effects is often undetermined. Similarly, the clinical pharmacogenomic effects associated with various alleles of the cytochrome P450 family of proteins, and their role in acute dystonic reactions, are also presently unknown.

Case presentation

We describe a woman presenting with acute dystonic reactions to ondansetron, prochlorperazine, and metoclopramide followed by persistent focal dystonia. A similar family history was reported in her siblings and her father to prochlorperazine, drugs all metabolized by the cytochrome P450 2D6 (CYP2D6) enzyme. Pharmacogenomic testing indicated the patient was heterozygous for the intermediate metabolizer *41 allele (CYP2D6 2988G>A, NM_000106.6:c.985+39G>A, rs28371725). Her father was homozygous for this CYP2D6 *41 allele, and consequently, her siblings were obligate carriers.

Conclusions

The metabolism of ondansetron, metoclopramide, or prochlorperazine in patients with the *41 CYP2D6 allele has not been studied. In this family, clinical evidence implicates the *41 CYP2D6 allele as causing extrapyramidal adverse pharmacologic reactions. Patients with a family history of medication-induced dystonia involving these medications should be considered for pharmacogenomic testing, and patients carrying the *41 CYP2D6 allele should consider reduction or avoidance of CYP2D6-mediated medications to minimize the potential risk of adverse extrapyramidal effects.

Cell-intrinsic effects of TorsinA(ΔE) disrupt dopamine release in a mouse model of TOR1A dystonia

TOR1A-associated dystonia, otherwise known as DYT1 dystonia, is an inherited dystonia caused by a three base-pair deletion in the TOR1A gene (TOR1AΔE). Although the mechanisms underlying the dystonic movements are largely unknown, abnormalities in striatal dopamine and acetylcholine neurotransmission are consistently implicated whereby dopamine release is reduced while cholinergic tone is increased. Because striatal cholinergic neurotransmission mediates dopamine release, it is not known if the dopamine release deficit is mediated indirectly by abnormal acetylcholine neurotransmission or if Tor1a(ΔE) acts directly within dopaminergic neurons to attenuate release. To dissect the microcircuit that governs the deficit in dopamine release, we conditionally expressed Tor1a(ΔE) in either dopamine neurons or cholinergic interneurons in mice and assessed striatal dopamine release using ex vivo fast scan cyclic voltammetry or dopamine efflux using in vivo microdialysis. Conditional expression of Tor1a(ΔE) in cholinergic neurons did not affect striatal dopamine release. In contrast, conditional expression of Tor1a(ΔE) in dopamine neurons reduced dopamine release to 50% of normal, which is comparable to the deficit in Tor1a^+/ΔE knockin mice that express the mutation ubiquitously. Despite the deficit in dopamine release, we found that the Tor1a(ΔE) mutation does not cause obvious nerve terminal dysfunction as other presynaptic mechanisms, including electrical excitability, vesicle recycling/refilling, Ca²⁺ signaling, D2 dopamine autoreceptor function and GABA_B receptor function, are intact. Although the mechanistic link between Tor1a(ΔE) and dopamine release is unclear, these results clearly demonstrate that the defect in dopamine release is caused by the action of the Tor1a(ΔE) mutation within dopamine neurons.

Paroxysmal Genetic Movement Disorders and Epilepsy

Paroxysmal movement disorders include paroxysmal kinesigenic dyskinesia, paroxysmal non-kinesigenic dyskinesia, paroxysmal exercise-induced dyskinesia, and episodic ataxias. In recent years, there has been renewed interest and recognition of these disorders and their intersection with epilepsy, at the molecular and pathophysiological levels. In this review, we discuss how these distinct phenotypes were constructed from a historical perspective and discuss how they are currently coalescing into established genetic etiologies with extensive pleiotropy, emphasizing clinical phenotyping important for diagnosis and for interpreting results from genetic testing. We discuss insights on the pathophysiology of select disorders and describe shared mechanisms that overlap treatment principles in some of these disorders. In the near future, it is likely that a growing number of genes will be described associating movement disorders and epilepsy, in parallel with improved understanding of disease mechanisms leading to more effective treatments.

Rethinking the risks and benefits of long-term maintenance in schizophrenia

This review addresses the risks and benefits of long-term maintenance antipsychotic treatment for patients that extends beyond two years. It focuses on framing discussions with patients who are recovering from a first episode. For these patients the evidence strongly supports the benefits over the risk for the first two years. However, both the clinical side effects of antipsychotics and the possible long-term effects of dopamine blocking drugs on the brain require a more nuanced discussion beyond this initial period. In most cases, the decision will be to continue antipsychotics but to consider strategies for mitigating the risks of drugs. This review provides information about the relative risks of dose reduction and intermittent treatment.

Nausea and Vomiting Not Related to Cancer Therapy: Intractable Problem or Clinical Challenge?

PURPOSE

Unlike therapy-related nausea and vomiting (chemotherapy or radiotherapy induced), nausea and vomiting (N/V) in patients with advanced cancer is often multicausal and thus presents unique challenges. Few professional guidelines address the palliative management of N/V, and those that do are insufficiently detailed to bolster clinical decision-making. Nonetheless, oncology advanced practitioners (APs) are frequently challenged to manage these high-impact symptoms. This requires collaborating with other oncology care providers and cultivating a knowledge base to educate and mentor professional colleagues to optimize N/V unrelated to treatment.

METHODS

Literature reviewed included current and classic articles that address the physiologic bases of N/V related to disease and with malignant bowel obstruction, agents used to alleviate nausea or N/V, and nonpharmacologic adjunctive measures. This information was framed within palliative care and symptom management clinical experience.

RESULTS

This review article summarizes what is known about the neuropharmacology of N/V in advanced disease. Focused assessment, pharmacologic agents (antiemetics, central neuromodulators, and peripheral prokinetic agents), and nondrug adjunctive measures that may be useful for N/V are included.

CONCLUSIONS

Managing N/V in advanced cancer is a quality-of-life imperative that requires persistence and interprofessional collaboration among oncology APs and other clinicians to personalize management. This work can change the perception that N/V related to progressive disease is frequently intractable to one that considers it as a manageable clinical challenge.

New generation VMAT2 inhibitors induced parkinsonism

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Drug induced parkinsonism caused by valbenazine and deutetrabenazine.

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Possible side effects of VMAT-2 inhibitors.

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Valbenazine and deutetrabenazine can unmask underlying Parkinson’s Disease.

Influence of magnesium supplementation and L-type calcium channel blocker on haloperidol-induced movement disturbances

Haloperidol (Hal) is an antipsychotic related to movement disorders. Magnesium (Mg) showed benefits on orofacial dyskinesia (OD), suggesting its involvement with N-methyl-D-aspartate receptors (NMDAR) since it acts blocking calcium channels. Comparisons between nifedipine (NIF; a calcium channel blocker) and Mg were performed to establish the Mg mechanism. Male rats concomitantly received Hal and Mg or NIF for 28 days, and OD behaviors were weekly assessed. Both Mg and NIF decreased Hal-induced OD. Hal increased Ca²⁺-ATPase activity in the striatum, and Mg reversed it. In the cortex, both Mg and NIF decreased such activity. Dopaminergic and glutamatergic immunoreactivity were modified by Hal and treatments: i) in the cortex: Hal reduced D1R and D2R, increasing NMDAR immunoreactivity. Mg and NIF reversed this Hal influence on D1R and NMDAR, while only Mg reversed Hal effects on D2R levels; ii) in the striatum: Hal decreased D2R and increased NMDAR while Mg and NIF decreased D1R and reversed the Hal-induced decreasing D2R levels. Only Mg reversed the Hal-induced increasing NMDAR levels; iii) in the substantia nigra (SN): while Hal increased D1R, D2R, and NMDAR, both Mg and NIF reversed this influence on D2R, but only Mg reversed the Hal-influence on D1R levels. Only NIF reversed the Hal effects on NMDAR immunoreactivity. These findings allow us to propose that Mg may be useful to minimize Hal-induced movement disturbances. Mg molecular mechanism seems to be involved with a calcium channel blocker because the NIF group showed less expressive effects than the Mg group.

Recent developments in drug-induced movement disorders: a mixed picture

A large and ever-growing number of medications can induce various movement disorders. Drug-induced movement disorders are disabling but are often under-recognised and inappropriately managed. In particular, second generation antipsychotics, like first generation agents, are associated with potentially debilitating side-effects, most notably tardive syndromes and parkinsonism, as well as potentially fatal acute syndromes. Appropriate, evidence-based management is essential as these drugs are being prescribed to a growing population vulnerable to these side-effects, including children and elderly people. Prevention of the development of drug-induced movement disorders is an important consideration when prescribing medications that can induce movement disorders. Recent developments in diagnosis, such as the use of dopamine transporter imaging for drug-induced parkinsonism, and treatment, with the approval of valbenazine and deutetrabenazine, the first drugs indicated for tardive syndromes, have improved outcomes for many patients with drug-induced movement disorders. Future research should focus on development of safer antipsychotics and specific therapies for the different tardive syndromes and the treatment of drug-induced parkinsonism.

Abnormal involuntary movement scale in tardive dyskinesia: Minimal clinically important difference

BACKGROUND

A minimal clinically important difference has not been established for the Abnormal Involuntary Movement Scale in patients with tardive dyskinesia. Valbenazine is a vesicular monoamine transporter 2 inhibitor approved for the treatment of tardive dyskinesia in adults. Efficacy in randomized, double-blind, placebo-controlled trials was defined as the change from baseline in Abnormal Involuntary Movement Scale total score (sum of items 1-7).

OBJECTIVES

To estimate an minimal clinically important difference for the Abnormal Involuntary Movement Scale using valbenazine trial data and an anchor-based method.

METHODS

Data were pooled from three 6-week double-blind, placebo-controlled trials: KINECT (NCT01688037), KINECT 2 (NCT01733121), and KINECT 3 (NCT02274558). Valbenazine doses were pooled for analyses as follows: "low dose," which includes 40 or 50 mg/day; and "high dose," which includes 75 or 80 mg/day. Mean changes from baseline in Abnormal Involuntary Movement Scale total score were analyzed in all participants (valbenazine- and placebo-treated) with a Clinical Global Impression of Change-Tardive Dyskinesia or Patient Global Impression of Change score of 1 (very much improved) to 3 (minimally improved).

RESULTS

The least squares mean improvement from baseline to week 6 in Abnormal Involuntary Movement Scale total score was significantly greater with valbenazine (low dose: -2.4; high dose: -3.2; both, P < 0.001) versus placebo (-0.7). An minimal clinically important difference of 2 points was estimated based on least squares mean changes in Abnormal Involuntary Movement Scale total score in participants with a Clinical Global Impression of Change-Tardive Dyskinesia score ≤3 at week 6 (mean change: -2.2; median change: -2) or Patient Global Impression of Change score ≤3 at week 6 (mean change: -2.0; median change: -2).

CONCLUSIONS

Results from an anchor-based method indicate that a 2-point decrease in Abnormal Involuntary Movement Scale total score may be considered clinically important. © 2019 The Authors. Movement Disorders published by Wiley Periodicals, Inc. on behalf of International Parkinson and Movement Disorder Society.

Study on risk factors of extrapyramidal symptoms induced by antipsychotics and its correlation with symptoms of schizophrenia

Background

Extrapyramidal symptoms (EPS) are one of the most common and neglected side effects during the treatment of schizophrenia. The risk factors of EPS in Chinese patients with schizophrenia and its relationship with psychiatric symptoms and mood symptoms of schizophrenia remain unknown.

Aims

The main objective of this study is to explore the risk factors of EPS caused by antipsychotics and the relationship between EPS and psychotic symptoms and mood symptoms of schizophrenia.

Method

This study included 679 patients with schizophrenia who have met the diagnostic criteria of the Diagnostic and Statistical Manual of Mental Disorders-Fourth Edition. Patients were divided into the EPS group and the non-EPS group according to the scale rating criteria and whether the anticholinergics have been used. The differences between demographic data and characters of drug intake were compared between the two groups, and the risk factors of EPS were selected between those factors. Correlation analysis was performed on the severity of schizophrenia (Positive and Negative Symptoms Scale (PANSS), Calgary Depression Scale for Schizophrenia (CDSS) score) and EPS scale (Simpson-Angus Scale (SAS), Barnes Akathisia Rating Scale (BARS), Abnormal Involuntary Movement Scale (AIMS) score) in 679 patients. The differences between the PANSS subscale score and the CDSS score between the EPS group and the non-EPS group were compared.

Result

Compared with the non-EPS group, the EPS group patients are older, and they have a longer duration since first prescribed antipsychotics. The EPS group patients have higher frequency of atypical antipsychotics polytherapy and typical and atypical antipsychotics polytherapy or combined treatments with mood stabilisers. Logistic regression analysis shows that antipsychotics with high D2 receptor antagonistic effect and illness duration are the risk factors of EPS. The SAS score was significantly correlated with PANSS negative score, PANSS general psychopathological score and PANSS total score. The BARS scale score was significantly correlated with PANSS positive score, PANSS general psychopathological score, PANSS total score and CDSS total score. The AIMS scale score was significantly correlated with PANSS negative score. Compared with the non-EPS group, the EPS group patients have significantly higher PANSS negative score, PANSS general psychopathological score, PANSS total score and CDSS total score.

Conclusion

Antipsychotic drugs with high D2 receptor antagonism and disease duration are risk factors of EPS in Chinese patients with schizophrenia. The severity of various types of EPS is significantly correlated with the psychiatric and mood symptoms of schizophrenia, and psychiatric symptoms and mood symptoms were significantly more severe in the EPS group. The occurrence of EPS is associated with poor treatment outcome of schizophrenia.

Treatment of Tardive Dyskinesia: A General Overview with Focus on the Vesicular Monoamine Transporter 2 Inhibitors

Tardive dyskinesia (TD) encompasses the spectrum of iatrogenic hyperkinetic movement disorders following exposure to dopamine receptor-blocking agents (DRBAs). Despite the advent of atypical or second- and third-generation antipsychotics with a presumably lower risk of complications, TD remains a persistent and challenging problem. Prevention is the first step in mitigating the risk of TD, but early recognition, gradual withdrawal of offending medications, and appropriate treatment are also critical. As TD is often a persistent and troublesome disorder, specific antidyskinetic therapies are often needed for symptomatic relief. The vesicular monoamine transporter 2 (VMAT2) inhibitors, which include tetrabenazine, deutetrabenazine, and valbenazine, are considered the treatment of choice for most patients with TD. Deutetrabenazine-a deuterated version of tetrabenazine-and valbenazine, the purified parent product of one of the main tetrabenazine metabolites, are novel VMAT2 inhibitors and the only drugs to receive approval from the US FDA for the treatment of TD. VMAT2 inhibitors deplete presynaptic dopamine and reduce involuntary movements in many hyperkinetic movement disorders, particularly TD, Huntington disease, and Tourette syndrome. The active metabolites of the VMAT2 inhibitors have high affinity for VMAT2 and minimal off-target binding. Compared with tetrabenazine, deutetrabenazine and valbenazine have pharmacokinetic advantages that translate into less frequent dosing and better tolerability. However, no head-to-head studies have compared the various VMAT2 inhibitors. One of the major advantages of VMAT2 inhibitors over DRBAs, which are still being used by some clinicians in the treatment of some hyperkinetic disorders, including TD, is that they are not associated with the development of TD. We also briefly discuss other treatment options for TD, including amantadine, clonazepam, Gingko biloba, zolpidem, botulinum toxin, and deep brain stimulation. Treatment of TD and other drug-induced movement disorders must be individualized and based on the severity, phenomenology, potential side effects, and other factors discussed in this review.

Efficacy of low-dose D2/D3 partial agonist pramipexole on neuroleptic-induced extrapyramidal symptoms and symptoms of schizophrenia: a stage-1 open-label pilot study

OBJECTIVE

Some lines of evidence show that D₂/D₃ receptor partial agonist pramipexole may be effective in the treatment of extrapyramidal symptoms (EPS) and psychiatric symptoms of schizophrenia. Therefore, we analyzed whether a low dose of pramipexole (0.375-0.75 mg/day) has efficacy on EPS and symptoms of schizophrenia while maintaining tolerability.

METHODS

Ten subjects with EPS [including drug-induced parkinsonism (DIP) and akathisia] were recruited in a stage-1, open-label pilot study. All the subjects were treated with a low dose of pramipexole. The evaluations were performed at baseline, day 3, week 1, week 2, week 4, week 6, and week 8. The ratings of SAS, BARS, PANSS, CDSS, and CGI-S and adverse effects (AE) were recorded in every visit.

RESULTS

SAS total scores decreased significantly during the study in patients with DIP (P<0.001), and mild AEs were detected. Treatments with pramipexole did not show an anti-akathisia effect during the study, while 2 subjects experienced deterioration of akathisia and mood symptoms. The psychiatric symptoms of schizophrenia showed a trend of improvement during the study, but there was no improvement in depressive mood.

CONCLUSION

A low dose of pramipexole can significantly relieve antipsychotic-induced parkinsonism, but not akathisia. Improvements in psychiatric symptoms of schizophrenia were found, but the results of this study need to be validated in a larger sample. No improvement of mood disorder was detected.

Development and clinimetric assessment of a nurse-administered screening tool for movement disorders in psychosis

BACKGROUND

Movement disorders associated with exposure to antipsychotic drugs are common and stigmatising but underdiagnosed.

AIMS

To develop and evaluate a new clinical procedure, the ScanMove instrument, for the screening of antipsychotic-associated movement disorders for use by mental health nurses.

METHOD

Item selection and content validity assessment for the ScanMove instrument were conducted by a panel of neurologists, psychiatrists and a mental health nurse, who operationalised a 31-item screening procedure. Interrater reliability was measured on ratings for 30 patients with psychosis from ten mental health nurses evaluating video recordings of the procedure. Criterion and concurrent validity were tested comparing the ScanMove instrument-based rating of 13 mental health nurses for 635 community patients from mental health services with diagnostic judgement of a movement disorder neurologist based on the ScanMove instrument and a reference procedure comprising a selection of commonly used rating scales.

RESULTS

Interreliability analysis showed no systematic difference between raters in their prediction of any antipsychotic-associated movement disorders category. On criterion validity testing, the ScanMove instrument showed good sensitivity for parkinsonism (90%) and hyperkinesia (89%), but not for akathisia (38%), whereas specificity was low for parkinsonism and hyperkinesia, and moderate for akathisia.

CONCLUSIONS

The ScanMove instrument demonstrated good feasibility and interrater reliability, and acceptable sensitivity as a mental health nurse-administered screening tool for parkinsonism and hyperkinesia.

DECLARATION OF INTEREST

None.

Pediatric Iatrogenic Movement Disorders

The acute development of a movement disorder is often a dramatic and frightening experience for patients and families, often requiring urgent or emergent evaluation by a neurologist. In the assessment of these patients, one relies on the history, physical and neurologic examination to determine the etiology of the condition. We aim to demonstrate that a thorough medication history is an incredibly critical part of this evaluation as iatrogenic movement disorders can arise from exposure not only to psychoactive medications, but from drugs prescribed for a variety of nonneurologic disorders. This comprehensive review is organized by movement disorder semiology so that the reader can more readily develop a differential diagnosis when evaluating a patient with a movement disorder.

Tardive dyskinesia: Epidemiology

The term tardive syndrome (TS) encompasses a few different phenomenologic conditions, some of which occur in isolation and others in association with each other. This, along with the unusual confound for a drug side effect, in which increased use of the drug improves the problem, and the need for most patients to continue taking the offending drug, makes understanding the epidemiology difficult and unreliable. While the change from the "first generation" to the "second generation" of antipsychotic drugs is generally believed to have reduced the incidence of TS, prospective research studies have not supported that contention. Published reports have found point prevalences of 13% with second generation antipsychotics and 32% with first, yet others have found no differences. One study found increasing rates of TS with a 68% prevalence by 25 years, while another found a decreased prevalence over time, due presumably to masking effects of the antipsychotic drugs. Regardless of the possible differences, it is clear that TS remains a significant and common problem associated with almost all antipsychotic drugs. There have also been scattered reports of TS caused by drugs not known to inhibit dopamine receptors. These are reviewed and were found to be often of dubious reliability.

Dopamine Receptor Agonist Treatment of Idiopathic Dystonia: A Reappraisal in Humans and Mice

Although dystonia is often associated with abnormal dopamine neurotransmission, dopaminergic drugs are not currently used to treat dystonia because there is a general view that dopaminergic drugs are ineffective. However, there is little conclusive evidence to support or refute this assumption. Therefore, to assess the therapeutic potential of these compounds, we analyzed results from multiple trials of dopamine receptor agonists in patients with idiopathic dystonias and also tested the efficacy of dopamine receptor agonists in a mouse model of generalized dystonia. Our results suggest that dopamine receptor agonists were effective in some, but not all, patients tested. Further, the mixed D1/D2 dopamine receptor agonist apomorphine was apparently more effective than subtype selective D2 dopamine receptor agonists. However, rigorously controlled trials are still needed. In a mouse model of dystonia, a selective D1 dopamine receptor agonist was not effective while a selective D2 dopamine receptor had modest efficacy. However, when combined, these receptor-selective agonists acted synergistically to ameliorate the dystonia. Coactivation of D1 and D2 dopamine receptors using apomorphine or by increasing extracellular concentrations of dopamine was also effective. Thus, results from both clinical trials and tests in mice suggest that coactivation of D1 and D2 dopamine receptors may be an effective therapeutic strategy in some patients. These results support a reconsideration of dopamine receptors as targets for the treatment of dystonia, particularly because recent genetic and diagnostic advances may facilitate the identification of the subtypes of dystonia patients who respond and those who do not.

Movement Disorders Associated With Antipsychotic Medication in People With Schizophrenia: An Overview of Cochrane Reviews and Meta-Analysis

Movement disorders associated with antipsychotic medications are relatively common, stigmatising, and potentially disabling. Their prevalence in people with psychosis who are prescribed second-generation antipsychotics (SGAs) is uncertain, as is their level of recognition by clinicinas. We conducted meta-analyses of randomised controlled trials included in the Cochrane Database of Systematic Reviews on schizophrenia and schizophrenia-like psychoses to estimate the prevalence of new-onset dystonia, akathisia, parkinsonism, and tremor with SGAs (amisulpride, asenapine, aripiprazole, clozapine, olanzapine, paliperidone, quetiapine, risperidone, L-sulpiride, and ziprasidone) approved in Canada and the UK, comparing them with haloperidol and chlorpromazine. We used a random effects model because of the heterogeneity between-studies in drug dosage and method of ascertainment of movement disorders. Our systematic search yielded 37 Cochrane systematic reviews (28 for SGAs), which generated 316 informative randomised controlled trials (243 for SGAs). With respect to SGAs, prevalence estimates ranged from 1.4% (quetiapine) to 15.3% (L-sulpiride) for dystonia, 3.3% (paliperidone) to 16.4% (L-sulpiride) for akathisia, 2.4% (asenapine) to 29.3% (L-sulpiride) for parkinsonism, and 0.2% (clozapine) to 28.2% (L-sulpiride) for tremor. Prevalence estimates were not influenced by treatment duration, the use of a flexible or fixed dosing scheme, or whether studies used validated instruments for the screening/rating of movement disorders. Overall, we found high overlap on the prevalence of new-onset movement disorders across different SGAs precribed for established psychoses. Variations in prevalence figures across antipsychotic medications were observed for the different movement disorders. Differences in pharmacological properties, such as for the dopamine D2 R association rate and serotonin 5-HT2A antagonism, could contribute to this variation.

The Safety of Metoclopramide in Children: A Systematic Review and Meta-Analysis

INTRODUCTION

Metoclopramide is recommended for adults with breakthrough or refractory chemotherapy-induced nausea and vomiting (CINV) and for CINV prophylaxis in children. The drug regulatory agencies of Canada and the EU have revised the labelling of metoclopramide to contraindicate its use in children aged <1 year and to caution against its use in children aged <5 years and its duration of use beyond 5 days.

OBJECTIVE

This review describes the safety of metoclopramide in children when given for any indication.

METHODS

We conducted electronic searches in MEDLINE and Embase as of 9 March 2015. All studies in English reporting adverse effects associated with the use of metoclopramide in children (aged ≤18 years) were included. Adverse effects that had a cumulative incidence of at least 1 % and were reported in prospective studies were synthesized.

RESULTS

A total of 108 (57 prospective) studies involving 2699 patients (2745 metoclopramide courses) were included. The most common adverse effects reported in prospective studies of metoclopramide in children were extrapyramidal symptoms (EPS; 9 %, 95 % confidence interval [CI] 5-17), diarrhea (6 %, 95 % CI 4-9), and sedation (multiple-dose studies: 6 %, 95 % CI 3-12). Dysrhythmia, respiratory distress/arrest, neuroleptic malignant syndrome, and tardive dyskinesia were rarely associated with metoclopramide use.

LIMITATIONS

The definitions of adverse effects reported in the included studies were heterogeneous, and the risk of bias in most studies was moderate.

CONCLUSIONS

The most commonly reported adverse effects associated with the use of metoclopramide in children-EPS, diarrhea, and sedation-were reversible and of no long-term significance. Adverse effects that were life threatening or slow to resolve were rarely associated with its use in children.

Treatment of tardive dyskinesia with tetrabenazine or valbenazine: a systematic review

Up to 30% of patients taking antipsychotics may develop tardive dyskinesia (TD). Recent evidence-based recommendations demonstrate an unmet need for effective TD management. This systematic review was designed to update the evidence for TD treatment, comparing two vesicular monoamine transporter 2 (VMAT2) inhibitors, tetrabenazine and valbenazine. Of 487 PubMed/Embase search results, 11 studies met the review criteria. Valbenazine efficacy was demonstrated in rigorously designed clinical trials that meet the guidelines for AAN Class I evidence. Due to differences in study designs and a lack of standardized and controlled trials with tetrabenazine, a formal meta-analysis comparing the agents was not possible. However, valbenazine appears to have fewer side effects and a more favorable once-daily dosing regimen for the treatment of TD.

Geriatric oral and maxillofacial dysfunctions in the context of geriatric syndrome

OBJECTIVES

To propose the application of the concept of geriatric syndrome for common geriatric oral and maxillofacial dysfunctions and to suggest the necessity of developing effective evaluation methods for oral and maxillofacial frailty.

DESIGN

The concepts of frailty and geriatric syndrome based on multi-morbidity and polypharmacy were applied to five common geriatric oral medicinal dysfunctional problems: salivary gland hypofunction (dry mouth), chronic oral mucosal pain disorders (burning mouth symptoms), taste disorders (taste disturbances), swallowing disorders (dysphagia), and oral and maxillofacial movement disorders (oromandibular dyskinesia and dystonia).

RESULTS

Each of the dysfunctions is caused by various kinds of diseases and/or conditions and medications, thus the concept of geriatric syndrome could be applied. These dysfunctions, suggested as components of oral and maxillofacial geriatric syndrome, are associated and interacted with each other in a complexity of vicious cycle. The resulting functional impairments caused by this syndrome can cause oral and maxillofacial frailty.

CONCLUSIONS

Geriatric oral and maxillofacial dysfunctions could be better appreciated in the context of geriatric syndrome. The development of effective methods for evaluating the severity of these dysfunctions and the resulting frailty is essential.

Diagnosis and Management of Dystonia

PURPOSE OF REVIEW

This article highlights the clinical and diagnostic tools used to assess and classify dystonia and provides an overview of the treatment approach.

RECENT FINDINGS

In the past 4 years, the definition and classification of dystonia have been revised, and new genes have been identified in patients with isolated hereditary dystonia (DYT23, DYT24, and DYT25). Expanded phenotypes were reported in patients with combined dystonia, such as those with mutations in ATP1A3. Treatment offerings have expanded as there are more neurotoxins, and deep brain stimulation has been employed successfully in diverse populations of patients with dystonia.

SUMMARY

Diagnosis of dystonia rests upon a clinical assessment that requires the examiner to understand the characteristic disease features that are elicited through a careful history and physical examination. The revised classification system uses two distinct nonoverlapping axes: clinical features and etiology. A growing understanding exists of both isolated and combined dystonia as new genes are identified and our knowledge of the phenotypic presentation of previously reported genes has expanded. Genetic testing is commercially available for some of these conditions. Treatment options for dystonia include pharmacologic therapy, chemodenervation, and surgical intervention. Deep brain stimulation benefits many patients with various types of dystonia.

Adverse Drug Reactions Associated with Antipsychotics, Antidepressants, Mood Stabilizers, and Stimulants

The advent of psychotropic medications in the 1950s greatly impacted the practice of psychiatry. Since then, efforts have been made to produce effective medications with few side effects (SEs) or adverse drug reactions (ADRs). Newer psychotropics have been developed but are not without risk. ADRs and SEs can lead to medication noncompliance, morbidity, and mortality. In many cases, ADRs can be prevented and common SEs relieved through proper interventions. Nursing interventions are vital to improving patient safety and outcomes in mental health populations. This article discusses ADRs and SEs of antipsychotics, antidepressants, mood stabilizers, and stimulants.

Post-stroke dyskinesias

Strokes, whether ischemic or hemorrhagic, are among the most common causes of secondary movement disorders in elderly patients. Stroke-related (vascular) movement disorders, however, are uncommon complications of this relatively common disease. The spectrum of post-stroke movement disorders is broad and includes both hypo- and hyperkinetic syndromes. Post-stroke dyskinesias are involuntary hyperkinetic movements arising from cerebrovascular insults and often present with mixed phenotypes of hyperkinesia which can sometimes be difficult to classify. Nevertheless, identification of the most relevant motor phenotype, whenever possible, allows for a more specific phenomenological categorization of the dyskinesia and thus helps guide its treatment. Fortunately, post-stroke dyskinesias are usually self-limiting and resolve within 6 to 12 months of onset, but a short-term pharmacotherapy might sometimes be required for symptom control. Functional neurosurgical interventions targeting the motor thalamus or globus pallidus interna might be considered for patients with severe, disabling, and persistent dyskinesias (arbitrarily defined as duration longer than 12 months).

A new knock-in mouse model of l-DOPA-responsive dystonia

Abnormal dopamine neurotransmission is associated with many different genetic and acquired dystonic disorders. For instance, mutations in genes critical for the synthesis of dopamine, including GCH1 and TH cause l-DOPA-responsive dystonia. Despite evidence that implicates abnormal dopamine neurotransmission in dystonia, the precise nature of the pre- and postsynaptic defects that result in dystonia are not known. To better understand these defects, we generated a knock-in mouse model of l-DOPA-responsive dystonia (DRD) mice that recapitulates the human p.381Q>K TH mutation (c.1141C>A). Mice homozygous for this mutation displayed the core features of the human disorder, including reduced TH activity, dystonia that worsened throughout the course of the active phase, and improvement in the dystonia in response to both l-DOPA and trihexyphenidyl. Although the gross anatomy of the nigrostriatal dopaminergic neurons was normal in DRD mice, the microstructure of striatal synapses was affected whereby the ratio of axo-spinous to axo-dendritic corticostriatal synaptic contacts was reduced. Microinjection of l-DOPA directly into the striatum ameliorated the dystonic movements but cerebellar microinjections of l-DOPA had no effect. Surprisingly, the striatal dopamine concentration was reduced to ∼1% of normal, a concentration more typically associated with akinesia, suggesting that (mal)adaptive postsynaptic responses may also play a role in the development of dystonia. Administration of D1- or D2-like dopamine receptor agonists to enhance dopamine signalling reduced the dystonic movements, whereas administration of D1- or D2-like dopamine receptor antagonists to further reduce dopamine signalling worsened the dystonia, suggesting that both receptors mediate the abnormal movements. Further, D1-dopamine receptors were supersensitive; adenylate cyclase activity, locomotor activity and stereotypy were exaggerated in DRD mice in response to the D1-dopamine receptor agonist SKF 81297. D2-dopamine receptors exhibited a change in the valence in DRD mice with an increase in adenylate cyclase activity and blunted behavioural responses after challenge with the D2-dopamine receptor agonist quinpirole. Together, our findings suggest that the development of dystonia may depend on a reduction in dopamine in combination with specific abnormal receptor responses.

Sleep in patients with primary dystonia: A systematic review on the state of research and perspectives

Patients with primary dystonia, the third most prevalent movement disorder, suffer from a markedly reduced quality of life. This might, at least in part, be mediated by non-motor symptoms, including sleep disturbances. Characterising and treating sleep disturbances might provide new inroads to improve relevant patient-centred outcomes. This review evaluates the state of research on sleep in patients with dystonia and outlines an agenda for future research. A literature search was performed in July 2014 using PubMed, Medline via Ovid, PsycInfo, PsycArticles via Proquest and Embase via Ovid. Search results were screened for eligibility by two independent raters. Peer-reviewed publications reporting on sleep in patients with primary dystonia were included. Of 1445 studies identified through the search strategy, 18 met the inclusion criteria. In total, the included studies reported on 708 patients diagnosed with focal dystonia (cervical dystonia or blepharospasm), torsion dystonia, and dopa-responsive dystonia. The results indicate that at least half of the patients with focal cranial dystonia suffer from sleep disturbances, but excessive daytime sleepiness is uncommon. Sleep disturbance is associated with depressive symptoms. The frequency and duration of dystonic movements is markedly reduced during sleep. Reduced sleep quality appears to persist after treatment with botulinum toxin that successfully reduces motor symptoms. The findings are limited by a high clinical and methodological heterogeneity. Future research is needed to i) further characterize subjective and PSG sleep in patients with different types of dystonia, ii) determine the aetiology of sleep disturbances (e.g., abnormal brain function associated with dystonia, side effects of medication, psychological reasons), and iii) test whether targeted sleep interventions improve sleep and quality of life in patients with primary dystonia.