Updating the recommendations for treatment of tardive syndromes: A systematic review of new evidence and practical treatment algorithm

Anterior capsulotomy combined with subthalamic nucleus deep brain stimulation for tardive dystonia

BACKGROUND

Deep brain stimulation (DBS) has been reported as a therapy option for the motor dysfunction of severe tardive dystonia (TD). The major psychiatric diseases, however, are contraindications to DBS treatment in TD patients.

METHODS

Six severe, medically refractory TD patients undergoing bilateral anterior capsulotomy combined with bilateral subthalamic nucleus (STN)-DBS treatment were studied retrospectively at two time points: pre-operation, and 1-3 years post-operation. Burke-Fahn-Marsden Dystonia Rating Scale (BFMDRS) was used to assess the dystonia and disability. Depressive, anxiety, psychiatric symptoms, and Quality of Life (QoL) were evaluated using the 17-item Hamilton Depression Scale (HAMD-17), the 14-item Hamilton Anxiety Scale (HAMA-14), the Positive and Negative Syndrome Scale (PANSS), and 36-item Short-Form Health Survey (SF-36), respectively.

RESULTS

After receiving the combination treatment for 25 ± 11.6 months (range, 12-41 months), significant clinical symptom improvements were reported in TD patients. BFMDRS motor and disability scores were ameliorated by 78.5 ± 32.0% (p = 0.031) and 76.5 ± 38.6% (p = 0.031), respectively. The HAMD-17 and HAMA-14 scores were reduced by 60.3 ± 27.9% (p = 0.007) and 60.0 ± 24.6% (p = 0.009), respectively. Furthermore, the PANSS scores of the comorbidity schizophrenia TD patients decreased by 58.1 ± 6.0% (p = 0.022), and the QoL improved by 59.7 ± 14.1% (SF-36, p = 0.0001). During the research, there were no notable adverse effects or problems.

CONCLUSION

Bilateral anterior capsulotomy combined with bilateral STN-DBS may be an effective and relatively safe treatment option for severe TD comorbid with major psychiatric disorders.

Profiling deutetrabenazine extended-release tablets for tardive dyskinesia and chorea associated with Huntington's disease

INTRODUCTION

Tardive dyskinesia (TD) and Huntington's disease (HD)-associated chorea are persistent and disabling hyperkinetic disorders that can be treated with vesicular monoamine transporter type 2 (VMAT2) inhibitors, including the recently approved once-daily (QD) formulation of deutetrabenazine (DTBZ ER). While its efficacy and safety profile have not been directly investigated, currently available data confirms bioequivalence and similar bioavailability to the twice-daily formulation (DTBZ BID).

AREAS COVERED

The authors briefly review the pivotal trials establishing efficacy of DTBZ for TD and HD-associated chorea, the pharmacokinetic data for bioequivalence between QD and BID dosing of DTBZ, as well as dose proportionality evidence, titration recommendations, and safety profile for DTBZ ER.

EXPERT OPINION

Long-term data show that DTBZ is efficacious and well tolerated for the treatment of TD and HD-associated chorea. DTBZ ER likely demonstrates therapeutic equivalence with no new safety signals. Due to the lack of comparative clinical trial data, no evidence-based recommendation about choice of VMAT2 inhibitor or switching between VMAT2 inhibitors can be made about best practice. Ultimately, QD dosing may offer the chance of improved medication adherence, an important consideration in patients with complex treatment regimens and/or patients with cognitive decline.

Sustained Treatment Response and Global Improvements With Long-term Valbenazine in Patients With Tardive Dyskinesia

PURPOSE/BACKGROUND

Using data from KINECT® 4, a phase 3, 48-week study of valbenazine, post hoc analyses were conducted to assess long-term outcomes that are relevant to the real-world management of tardive dyskinesia (TD).

METHODS/PROCEDURES

Post hoc analyses of the participants of the KINECT 4 study who completed 48 weeks of open-label valbenazine (40 or 80 mg) treatment were conducted. Valbenazine effects on TD were evaluated using the Abnormal Involuntary Movement Scale (AIMS), Clinical Global Impression of Change-TD (CGI-TD), and Patient Global Impression of Change (PGIC).

FINDINGS/RESULTS

Of 103 participants completing 48 weeks of treatment, 55% experienced clinically meaningful improvement (defined as ≥2-point reduction in AIMS total score [sum of items 1 - 7, evaluated by site raters]) by week 4; at week 48, 97% met this threshold. The percentage of completers who achieved AIMS total score response thresholds of ≥10% to ≥90% increased over time, with 86% of completers reaching ≥50% improvement. Of the 40 (39%) completers with AIMS ≥50% response at week 8, 38 (95%) sustained this response at week 48; 81% of those who did not meet this threshold at week 8 had achieved it by week 48. At week 48, more than 85% of completers achieved CGI-TD and PGIC ratings of "much improved" or "very much improved."

IMPLICATIONS/CONCLUSIONS

The majority of participants who completed 48 weeks of treatment with once-daily valbenazine experienced substantial clinically meaningful and sustained TD improvements. These findings indicate that valbenazine can be a highly effective long-term treatment in patients with TD.

Mining of neurological adverse events associated with valbenazine: A post-marketing analysis based on FDA adverse event reporting system

PURPOSE

Valbenazine is commonly used to treat tardive dyskinesia, and we conducted a pharmacovigilance analysis using the Food and Drug Administration Adverse Event Reporting System (FAERS) to evaluate neurological safety signals associated with valbenazine.

METHODS

Data was collected in FAERS from the second quarter of 2017 to the fourth quarter of 2023 for data cleaning. Neurological adverse event (AE) signals of valbenazine were mined by calculating reporting odds ratios (ROR), information component (IC) and empirical Bayesian geometric mean (EBGM). The serious and non-serious cases and signals were prioritized using a rating scale.

RESULTS

The number of neurological AE reports where the primary suspect (PS) drug was 8981 for valbenazine. Significant AE signals were identified by the preferred term (PT) analysis for valbenazine, including somnolence (ROR 19.69), tremor (ROR 15.17), and tardive dyskinesia (ROR 236.91), among which 18 AEs were identified as new signals. Patient age (p < 0.009) and sex (p = 0.197) might be associated with an increased risk of neurological AE severity. Notably, the association between valbenazine and neurological disorders remained when stratified by sex, age, and reporter type. AE timing analysis was performed for the drug and four moderate clinical priority signals [i.e., somnolence, balance disorder, parkinsonism, and akathisia (priorities 7)], showing the same early failure type profiles.

CONCLUSIONS

The increase in neurological safety signals is identified in the post-marketing research of valbenazine. Clinicians need to pay attention to not only common AEs but also be alert to new neurological AE signals when using valbenazine.

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.

Assessment and Treatment of Abnormal Involuntary Movements: A Clinically Focused Narrative Review

LEARNING OBJECTIVES

After participating in this CME activity, the psychiatrist should be better able to:• Categorize and describe different types of abnormal involuntary movements (AIMs).• Identify assessment tools and treatment options for AIMs.

ABSTRACT

Abnormal involuntary movements (AIMs) comprise a diverse group of movement disorders characterized by uncontrolled and unintended movements (e.g., tremors, tics, dystonia). AIMs can occur at any stage of life and pose significant challenges for clinicians. It is difficult to determine their underlying causes due to the complex neurobiological mechanisms involved. Therefore, it is crucial to quantify the severity and progression of AIMs using well-validated measurement scales, such as the Abnormal Involuntary Movement Scale (AIMS). By employing reliable assessment approaches, clinicians can objectively evaluate the motoric manifestations of AIMs and track them over time. Treatment of AIMs varies depending on their nature and etiology. While AIMs often respond to treatment, serious side effects can undermine treatment efficacy. In this clinically focused narrative review, we categorize different types of AIMs and discuss their neurobiological aspects. Further, we emphasize the importance of using well-validated measurement scales for accurate assessment and discuss available treatment modalities that target the specific AIMs manifestations. Additionally, we cover the need for comprehensive care to address the multifaceted nature of AIMs, accounting for their physical manifestations as well as their psychological, social, and functional toll on patients. By embracing a multidisciplinary approach, health care professionals can provide patient-centered care that promotes overall well-being and enhances the lives of patients coping with AIMs. Regular follow-up assessments are necessary to monitor treatment response, adjust medications when needed, and provide ongoing support for individuals affected by AIMs.

Tardive dyskinesia in Asia- current clinical practice and the role of neurologists in the care pathway

Tardive dyskinesia (TD) is a movement disorder that can arise as a side effect of treatment with dopamine receptor-blocking agents (DRBAs), including antipsychotic drugs (APDs) used to manage psychotic illnesses. Second-generation APDs (SGAs) are often preferred to first-generation drugs due to their lower propensity to cause TD, however many SGAs-treated patients still develop the condition. Although TD is a global health concern, evidence regarding the occurrence of TD and how it is managed in Asian countries is currently limited. This article reports the results of a systematic review of the published literature on TD focusing on its prevalence, types of patients, knowledge of the condition, causative factors, and usual treatment pathways in clinical practice in Asian countries. Epidemiological data suggest that the prevalence of TD is increasing globally due to an overall rise in APD use, contributing factors being polypharmacy with multiple APDs, the use of higher than necessary doses, and off-label use for non-psychotic indications. Although exact prevalence figures for TD in Asian countries are difficult to define, there is a similar pattern of rising APD use which will result in increasing numbers of TD patients in this region. These issues need to be addressed and strategies developed to minimize TD risk and manage this disabling condition which impacts patients' quality of life and daily functioning. To date, both research into TD has been predominantly psychiatry focused and the perspectives from neurologists regarding the clinical management of this challenging condition are scarce. However, neurologists have an essential role in managing the movement disorders manifestations that characterize TD. Optimum management of TD, therefore, should ideally involve collaboration between psychiatrists and neurologists in joint care pathways, wherever practical. Collaborative pathways are proposed in this article, and the challenges that will need to be addressed in Asian countries to improve the care of people with TD are highlighted, with a focus on the neurologist's viewpoint and the implications for the management of TD globally.

Exploring real-world symptom impact and improvement in well-being domains for tardive dyskinesia in VMAT2 inhibitor-treated patients via clinician survey and chart review

Introduction

Two vesicular monoamine transporter 2 (VMAT2) inhibitors are approved in the United States (US) for the treatment of tardive dyskinesia (TD). There is a paucity of information on the impact of VMAT2 inhibitor treatment on patient social and physical well-being. The study objective was to elucidate clinician-reported improvement in symptoms and any noticeable changes in social or physical well-being in patients receiving VMAT2 inhibitors.

Methods

A web-based survey was offered to physicians, nurse practitioners, and physician assistants based in the US who prescribed valbenazine for TD within the past 24 months. Clinicians reported data from the charts of patients who met the inclusion criteria and were allowed to recall missing information.

Results

Respondents included 163 clinicians who reviewed charts of 601 VMAT2-treated patients with TD: 47% had TD symptoms in ≥2 body regions, with the most common being in the head or face and upper extremities. Prior to treatment, 93% of patients showed impairment in ≥1 social domain, and 88% were impaired in ≥1 physical domain. Following treatment, among those with improvement in TD symptoms (n = 540), 80% to 95% showed improvement in social domains, 90% to 95% showed improvement in physical domains, and 73% showed improvement in their primary psychiatric condition.

Discussion

In VMAT2-treated patients with TD symptom improvement, clinicians reported concomitant improvement in psychiatric disorder symptoms and in social and physical well-being. Regular assessment of TD impact on these types of domains should occur simultaneously with movement disorder ratings when evaluating the value of VMAT2 inhibitor therapy.

Efficacy and safety of botulinum toxin for treating motor dysfunction in patients with Parkinson's disease: a systematic review and meta-analysis

OBJECTIVE

To evaluate the efficacy and safety of botulinum toxin (BTX) for motor dysfunction in Parkinson's disease (PD).

DESIGN

Systematic review and meta-analysis.

DATA SOURCES

Searches of PubMed, EMBASE and the Cochrane Library, from database inception to 20 October 2022.

ELIGIBILITY CRITERIA

Studies reported in English with adult PD patients treated with BTX.

DATA EXTRACTION AND SYNTHESIS

Primary outcomes were United Parkinson's Disease Rate Scale Section (UPDRS) III (or its items) and Visual Analogue Scale (VAS). Secondary outcomes were UPDRS-II (or its items), Freezing of Gait Questionnaire (FOG-Q), Timed Up and Go test (TUG) and treatment-related adverse events (TRAEs). Mean difference (MD) or standardised MD (SMD) before and after treatment with 95% CIs were used for continuous variables and risk ratios (RRs) with 95% CIs was used for TRAEs.

RESULTS

Six randomised controlled trials (RCTs) and six non-RCTs (case series) were included (ntotal=224 participants, nRCT=165). No significant difference was found in pooled results of UPDRS-III (available in four RCTs and two non-RCTs, SMD=-0.19, 95% CI -0.98 to 0.60), UPDRS-II (four RCTs and one non-RCT, SMD=-0.55, 95% CI -1.22 to 0.13), FOG-Q (one RCT and one non-RCT, SMD=0.53, 95% CI -1.93 to 2.98) or the risk of TRAEs (five RCTs, RR 0.87, 95% CI 0.37 to 2.01). Significant decreases were found in pooled VAS score (three RCTs and five non-RCTs, MD=-2.14, 95% CI -3.05 to -1.23) and TUG (MD=-2.06, 95% CI -2.91 to -1.20) after BTX treatment.

CONCLUSIONS

BTX may not be associated with motor symptoms alleviation, although it benefits pain alleviation and functional mobility improvement.

Historical developments, hotspots, and trends in tardive dyskinesia research: a scientometric analysis of 54 years of publications

Background

Since being recognized as an important drug-induced clinical entity during the 1960s, tardive dyskinesia (TD) has generated an extensive body of research seeking to understand its clinical characteristics, epidemiology, pathophysiology and management. Modern scientometric approaches allow interactive visualization of large bodies of literature to identify trends and hotspots within knowledge domains. This study thus aimed to provide a comprehensive scientometric review of the TD literature.

Methods

Web of Science was searched for articles, reviews, editorials and letters with the term "tardive dyskinesia" in the title, abstract, or keywords through 12/31/2021. A total of 5,228 publications and 182,052 citations were included. Annual research output, prominent research areas, authors, affiliations and countries were summarized. VOSViewer and CiteSpace were used for bibliometric mapping and co-citation analysis. Structural and temporal metrics were used to identify key publications in the network.

Results

TD-related publications peaked in the 1990s, gradually declined after 2004, and showed a further small increase after 2015. The most prolific authors were Kane JM, Lieberman JA, and Jeste DV overall (1968-2021), and Zhang XY, Correll CU and Remington G in the last decade (2012-2021). The most prolific journal was the Journal of Clinical Psychiatry overall, and the Journal of Psychopharmacology in the last decade. Knowledge clusters in the 1960-1970s dealt with clinical and pharmacological characterization of TD. In the 1980s, epidemiology, clinical TD assessment, cognitive dysfunction and animal models predominated. During the 1990s, research diverged into pathophysiological studies, especially oxidative stress, and clinical trials on atypical antipsychotics, with a focus on clozapine and bipolar disorder. In the 1990-2000s, pharmacogenetics emerged. More recent clusters include serotonergic receptors, dopamine-supersensitivity psychosis, primary motor abnormalities of schizophrenia, epidemiology/meta-analyses, and advances in TD treatment, particularly vesicular monoamine transporter-2 inhibitors since 2017.

Conclusion

This scientometric review visualized the evolution of scientific knowledge on TD over more than five decades. These findings will be useful for researchers to find relevant literature when writing scientific articles, choosing appropriate journals, finding collaborators or mentors for research, and to understand the historical developments and emerging trends in TD research.

Clinical Evolution of Tardive Cervical Dystonia from Antecollis to Retrocollis

Tardive dystonia occurs after exposure, over months to years, to antipsychotics and other drugs that block dopaminergic receptors. Anterocollis is a rare form of cervical dystonia which is usually disabling for the patient. Here, we present the case of a 61-year-old woman with Alzheimer's dementia diagnosed eight years ago who was previously medicated with antipsychotics. Two years before admission, she was medicated with olanzapine. She presented to the emergency room with a sustained flexion posture of the neck that was difficult to feed. She had a marked and fixed anterocollis and severe akathisia. After the administration of propofol to perform computerized tomography, the abnormal posture disappeared. Subsequently, she was started on biperiden without improvement. One week later, olanzapine was suspended, and she was progressively started on propranolol, trihexyphenidyl, and tetrabenazine. Cervical posture improved, but two weeks later, she presented with a left laterocollis, which allowed feeding, and improvement of akathisia. We present a case of tardive dystonia supported by the beginning of dystonia five months after olanzapine administration and improvement after its suspension. The coexistence of degenerative pathology is a risk factor for dystonia, which often persists despite the suspension of the causative agent. Therefore, non-pharmacological treatment and approach with antipsychotics with a better profile of extrapyramidal effects should be preferred in patients with dementia.

Impact of possible tardive dyskinesia on physical wellness and social functioning: results from the real-world RE-KINECT study

BACKGROUND

Tardive dyskinesia (TD) is a persistent and potentially disabling movement disorder associated with antipsychotic use. Data from RE-KINECT, a real-world study of antipsychotic-treated outpatients, were analyzed to assess the effects of possible TD on patient health and social functioning.

METHODS

Analyses were conducted in Cohort 1 (patients with no abnormal involuntary movements) and Cohort 2 (patients with possible TD per clinician judgment). Assessments included: EuroQoL's EQ-5D-5L utility (health); Sheehan Disability Scale (SDS) total score (social functioning); patient- and clinician-rated severity of possible TD ("none", "some", "a lot"); and patient-rated impact of possible TD ("none", "some", "a lot"). Regression models were used to analyze the following: associations between higher (worse) severity/impact scores and lower (worse) EQ-5D-5L utility (indicated by negative regression coefficients); and associations between higher (worse) severity/impact scores and higher (worse) SDS total score (indicated by positive regression coefficients).

RESULTS

In Cohort 2 patients who were aware of their abnormal movements, patient-rated TD impact was highly and significantly associated with EQ-5D-5L utility (regression coefficient: - 0.023, P < 0.001) and SDS total score (1.027, P < 0.001). Patient-rated severity was also significantly associated with EQ-5D-5L utility (- 0.028, P < 0.05). Clinician-rated severity was moderately associated with both EQ-5D-5L and SDS, but these associations were not statistically significant.

CONCLUSIONS

Patients were consistent in evaluating the impacts of possible TD on their lives, whether based on subjective ratings ("none", "some", "a lot") or standardized instruments (EQ-5D-5L, SDS). Clinician-rated severity of TD may not always correlate with patient perceptions of the significance of TD.

Deep Brain Stimulation in the Treatment of Tardive Dyskinesia

Tardive dyskinesia (TD) is a phenomenon observed following the predominantly long-term use of dopamine receptor blockers (antipsychotics) widely used in psychiatry. TD is a group of involuntary, irregular hyperkinetic movements, mainly in the muscles of the face, eyelid, lips, tongue, and cheeks, and less frequently in the limbs, neck, pelvis, and trunk. In some patients, TD takes on an extremely severe form, massively disrupting functioning and, moreover, causing stigmatization and suffering. Deep brain stimulation (DBS), a method used, among others, in Parkinson's disease, is also an effective treatment for TD and often becomes a method of last resort, especially in severe, drug-resistant forms. The group of TD patients who have undergone DBS is still very limited. The procedure is relatively new in TD, so the available reliable clinical studies are few and consist mainly of case reports. Unilateral and bilateral stimulation of two sites has proven efficacy in TD treatment. Most authors describe stimulation of the globus pallidus internus (GPi); less frequent descriptions involve the subthalamic nucleus (STN). In the present paper, we provide up-to-date information on the stimulation of both mentioned brain areas. We also compare the efficacy of the two methods by comparing the two available studies that included the largest groups of patients. Although GPi stimulation is more frequently described in literature, our analysis indicates comparable results (reduction of involuntary movements) with STN DBS.

Tardive Syndrome Is a Mysterious Phenomenon with Different Clinical Manifestations-Review

Tardive syndrome (TS) refers to persistent hyperkinetic, hypokinetic, and sensory complaints appearing after chronic neuroleptics and other dopamine receptor-blocking agents (DRBAs). It is defined as involuntary movements, often rhythmic, choreiform, or athetoid, involving the tongue, face, extremities, and sensory urges such as akathisia and lasts for a few weeks. TS develops in association with neuroleptic medication usage for a few months at least. There is usually a delay between the initiation of the causative drug and the onset of abnormal movements. However, it was soon noted that TS can also develop early, even days or weeks after DRBAs begin. However, the longer the exposure, the greater the risk of developing TS. Tardive dyskinesia, dystonia, akathisia, tremor, and parkinsonism are frequent phenomenologies of this syndrome.

[Tardive dyskinesia]

Tardive dyskinesia (TD) is a delayed, often irreversible iatrogenic movement disorder caused by long-term use of that dopamine receptors blocking drugs. Prevention of TD is paramount, and clinicians should follow best practice recommendations for prescribing antipsychotics, as well as reduction the using of dopamine receptor blocking drugs for non-psychiatric prescriptions. Replacement of antipsychotics with lower affinity for D2 receptors drugs, addition of VMAT2 (tetrabenazine), botulinum therapy, amantadine may be effective. In detection and incurable cases, the possibility of neuromodulation of brain structures should be considered. Most methods for testing TD currently have an insufficient level of evidence, although they include recommendations from professional communities. There is a great need for new clinical trials.

Treatment for cognitive and neuropsychiatric non-motor symptoms in Parkinson's disease: current evidence and future perspectives

INTRODUCTION

Non-motor symptoms (NMS) affect patients with Parkinson's disease (PD) from the prodromal to the advanced stages. NMS phenotypes greatly vary and have a huge impact on patients' and caregivers' quality of life (QoL). The management of cognitive and neuropsychiatric NMS remains an unmet need.

AREAS COVERED

The authors, herein, review the dopaminergic and non-dopaminergic pathogenesis, clinical features, assessment, and pharmacological and non-pharmacological treatments of cognitive and neuropsychiatric NMS in PD. They discuss the current evidence and report the findings of an overview of ongoing trials on pharmacological and selected non-pharmacological strategies.

EXPERT OPINION

The treatment of cognitive and neuropsychiatric NMS in PD is poorly explored, and therapeutic options are unsatisfactory. Pharmacological treatment of cognitive NMS is based on symptomatic active principles used in Alzheimer's disease. Dopamine agonists, selective serotonin, and serotonin-norepinephrine reuptake inhibitors have some evidence on PD-related depression. Clozapine, quetiapine, and pimavanserin may be considered for psychosis in PD. Evidence on the treatment of other neuropsychiatric NMS is limited or lacking. Addressing pathophysiological and clinical issues, which hamper solid evidence on the treatment of cognitive and neuropsychiatric NMS, may reduce the impact on QoL for PD patients and their caregivers.

Updated Perspectives on the Management of Drug-Induced Parkinsonism (DIP): Insights from the Clinic

Parkinsonism refers to the clinical combination of bradykinesia, rigidity, tremor, and postural instability. Parkinsonism is often neurodegenerative, but it can be secondary or iatrogenic, as in drug-induced parkinsonism (DIP), which is the topic of this review. We review the pathophysiology of DIP, differentiate DIP and idiopathic Parkinson's disease (PD), list culprit medications in the development of DIP, discuss the diagnosis of DIP as well as the motor and nonmotor signs and symptoms that can help with differentiation of DIP and PD, and detail the management of DIP.

Pharmacokinetic and Pharmacologic Characterization of the Dihydrotetrabenazine Isomers of Deutetrabenazine and Valbenazine

Valbenazine and deutetrabenazine are vesicular monoamine transporter 2 (VMAT2) inhibitors approved for tardive dyskinesia. The clinical activity of valbenazine is primarily attributed to its only dihydrotetrabenazine (HTBZ) metabolite, [+]-α-HTBZ. Deutetrabenazine is a deuterated form of tetrabenazine and is metabolized to four deuterated HTBZ metabolites: [+]-α-deuHTBZ, [+]-β-deuHTBZ, [-]-α-deuHTBZ, and [-]-β-deuHTBZ. An open-label, crossover study characterized the pharmacokinetic profiles of the individual deuHBTZ metabolites, which have not been previously reported. VMAT2 inhibition and off-target interactions of the deuHTBZ metabolites were evaluated using radioligand binding. The only valbenazine HTBZ metabolite, [+]-α-HTBZ, was a potent VMAT2 inhibitor, with negligible affinity for off-target dopamine, serotonin, and adrenergic receptors. Following deutetrabenazine administration, [-]-α-deuHTBZ represented 66% of circulating deuHTBZ metabolites and was a relatively weak VMAT2 inhibitor with appreciable affinity for dopamine (D_2S , D₃ ) and serotonin (5-HT_1A , 5-HT_2B , 5-HT₇ ) receptors. [+]-β-deuHTBZ was the most abundant deuHTBZ metabolite that potently inhibited VMAT2, but it represented only 29% of total circulating deuHTBZ metabolites. The mean half-life of [+]-α-HTBZ (22.2 hours) was ∼3× longer than that of [+]-β-deuHTBZ (7.7 hours). These findings are similar to studies with tetrabenazine, in that deutetrabenazine is metabolized to four deuHTBZ stereoisomers, the most abundant of which has negligible interaction with VMAT2 in vitro and appreciable affinity for several off-target receptors. In contrast, valbenazine's single HTBZ metabolite is a potent VMAT2 inhibitor in vitro with no discernible off-target activity. Determination of the effects of intrinsic/extrinsic variables on deutetrabenazine's safety/efficacy profile should incorporate assessment of the effects on all deuHTBZ metabolites.

Efficacy and safety of valbenazine in Japanese patients with tardive dyskinesia: A multicenter, randomized, double-blind, placebo-controlled study (J-KINECT)

AIM

Valbenazine is approved in the US for treatment of tardive dyskinesia (TD); however, efficacy/safety data in Asian populations are lacking. We assessed the efficacy/safety of valbenazine in Japanese patients.

METHODS

This phase II/III, multicenter, randomized, double-blind, placebo-controlled study (NCT03176771) included adult psychiatric patients with TD, who were randomly allocated to receive placebo or valbenazine (once-daily 40- or 80-mg) for a 6-week, double-blind period, after which the placebo group was switched to valbenazine for a 42-week extension. The primary endpoint was change from baseline in Abnormal Involuntary Movement Scale (AIMS) total score at Week 6; clinical global impression of improvement of TD (CGI-TD) was also assessed.

RESULTS

Of 256 patients, 86, 85, and 85 were allocated to the 40-mg valbenazine, 80-mg valbenazine, and placebo groups, respectively. Least-squares mean (95% confidence interval) change from baseline in AIMS score at Week 6 was -2.3 (-3.0 to -1.7) in the valbenazine 40-mg group, -3.7 (-4.4 to -3.0) in the 80-mg group, and -0.1 (-0.8 to 0.5) in the placebo group; both treatment groups showed statistically significant improvements vs. placebo. Patients switched to valbenazine at Week 6 showed similar improvements in AIMS scores, which were maintained to Week 48. Improvements in CGI-TD scores were observed for both treatment groups vs. placebo. Incidence of adverse events was highest in the 80-mg group; common events included nasopharyngitis, somnolence, schizophrenia worsening, hypersalivation, insomnia, and tremor.

CONCLUSION

The efficacy/safety profile of valbenazine was similar to that of previous clinical trials, supporting its use for TD treatment in Japanese patients.

Movement disorders of the mouth: a review of the common phenomenologies

Movement disorders of the mouth encompass a spectrum of hyperactive movements involving the muscles of the orofacial complex. They are rare conditions and are described in the literature primarily in case reports originating from neurologists, psychiatrists, and the dental community. The focus of this review is to provide a phenomenological description of different oral motor disorders including oromandibular dystonia, orofacial dyskinesia and orolingual tremor, and to offer management strategies for optimal treatment based on the current literature. A literature search of full text studies using PubMed/Medline and Cochrane library combined with a manual search of the reference lists was conducted until June 2021. Results from this search included meta-analyses, systematic reviews, reviews, clinical studies, case series, and case reports published by neurologists, psychiatrists, dentists and oral and maxillofacial surgeons. Data garnered from these sources were used to provide an overview of most commonly encountered movement disorders of the mouth, aiding physicians in recognizing these rare conditions and in initiating appropriate therapy.

Clozapine Use in a Movement Disorder Clinic

BACKGROUND

Clozapine is an effective antipsychotic for Parkinson's disease (PD) that does not worsen motor function and can improve tremor. It is approved for PD psychosis in Europe and Australia.

OBJECTIVE

The aim of this study was to report on the use of clozapine in a movement disorder clinic.

METHODS

We report on patients monitored during the COVID-19 pandemic in clinic over a 7-month period.

RESULTS

Sixty-five patients were seen, of whom 50 had PD. Thirty-one were treated for psychosis, 18 for refractory tremor and 1 for levodopa dyskinesias. The remainder had psychotic symptoms with dementia with Lewy bodies (n = 2) or other movement disorders. Four had clozapine discontinued because of sedation and 1 for agranulocytosis. Three had clozapine temporarily halted because of granulocytopenia but were rechallenged successfully.

CONCLUSIONS

When comparing clozapine use in this clinic as compared with others, we deduce that clozapine is likely significantly underutilized in the United States.

Minimal clinically important change in Abnormal Involuntary Movement Scale score in tardive dyskinesia as assessed in pivotal trials of deutetrabenazine

INTRODUCTION

Deutetrabenazine is approved by the US Food and Drug Administration to treat tardive dyskinesia (TD) based on 2 pivotal, 12-week, placebo-controlled studies (ARM-TD and AIM-TD) evaluating safety and efficacy in patients with baseline total motor Abnormal Involuntary Movement Scale (AIMS) score ≥6. This analysis estimated the minimal clinically important change (MCIC) in total motor AIMS score in TD patients treated with deutetrabenazine.

METHODS

The pooled analysis population included all patients in ARM-TD and AIM-TD who received study drug and had ≥1 postbaseline AIMS assessment. MCIC analyses were performed using Patient Global Impression of Change (PGIC) and Clinical Global Impression of Change (CGIC) as anchors. MCIC was defined as the mean change from baseline in total motor AIMS score in patients treated with deutetrabenazine who were rated minimally improved on PGIC or CGIC at Week 12.

RESULTS

This analysis included 295 patients (deutetrabenazine, n = 197; placebo, n = 98). At Week 12, the MCIC in deutetrabenazine-treated patients was -2.4 based on the PGIC and -2.1 based on the CGIC. Mean change from baseline in total motor AIMS score for placebo-treated patients rated minimally improved was -1.4 based on the PGIC and -1.5 based on the CGIC. The proportion of deutetrabenazine-treated patients who achieved improvement in total motor AIMS score by ≥2 and ≥3 points was 66% and 55%, respectively.

CONCLUSION

Using anchor-based methodology, the MCIC on the AIMS for deutetrabenazine in patients with TD was approximately -2, suggesting that a reduction in total motor AIMS score of ∼2 is associated with clinically meaningful improvement in TD symptoms.

Differentiating tardive dyskinesia: a video-based review of antipsychotic-induced movement disorders in clinical practice

Accurate diagnosis and appropriate treatment of tardive dyskinesia (TD) are imperative, as its symptoms can be highly disruptive to both patients and their caregivers. Misdiagnosis can lead to incorrect interventions with suboptimal or even deleterious results. To aid in the identification and differentiation of TD in the psychiatric practice setting, we review its clinical features and movement phenomenology, as well as those of other antipsychotic-induced movement disorders, with accompanying links to illustrative videos. Exposure to dopamine receptor blocking agents (DRBAs) such as antipsychotics or antiemetics is associated with a spectrum of movement disorders including TD. The differential diagnosis of TD is based on history of DRBA exposure, recent discontinuation or dose reduction of a DRBA, and movement phenomenology. Common diagnostic challenges are the abnormal behaviors and dyskinesias associated with advanced age or chronic mental illness, and other movement disorders associated with DRBA therapy, such as akathisia, parkinsonian tremor, and tremor related to use of mood stabilizing agents (eg, lithium, divalproex). Duration of exposure may help rule out acute drug-induced syndromes such as acute dystonia or acute/subacute akathisia. Another important consideration is the potential for TD to present together with other drug-induced movement disorders (eg, parkinsonism, parkinsonian tremor, and postural tremor from mood stabilizers) in the same patient, which can complicate both diagnosis and management. After documentation of the phenomenology, severity, and distribution of TD movements, treatment options should be reviewed with the patient and caregivers.

VMAT2 Inhibitors for the Treatment of Tardive Dyskinesia

Psychiatric nurses are at the forefront of optimizing psychiatric care, including educating patients and caregivers on the risks of antipsychotic-induced movement disorders such as tardive dyskinesia (TD). Nurses should be aware that all patients taking antipsychotics should be regularly monitored for the development of TD. Given the current pandemic and increase in telehealth, assessing for TD is challenging; however, evaluation can be successfully completed by implementing the best practices described in this paper. Once TD is diagnosed, nurses can reassure patients that safe and effective FDA-approved treatments for TD (e.g., valbenazine) are now available.

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.

PLAIN LANGUAGE SUMMARY

Plain Language Summary (In Japanese).

VISUAL SUMMARY

Visual Summary (In Japanese).

Tardive dyskinesia

Tardive dyskinesia is a group of hyperkinetic and hypokinetic movement disorders, following the administration of dopamine receptor-blocking drugs. The severity of these syndromes varies from soft forms to the development of life-degrading situations. Phenomenologically tardive dyskinesia can be represented both in isolation and in various combinations. Recognition of these syndromes early in the development of tardive dyskinesia can optimize therapeutic treatment and reduce the risk of severe complications. As a means of treatment, deutetrabenazine or valbenazine are used as first-line drugs, with resistance to therapy and in severe cases, drugs of other groups are used (amantadine, baclofen, botulinum toxin type A, clonazepam, donepezil, gabapentin, ginkgo biloba, levetiracetam, melatonin, pregabalin, thiamine, verapamil, vitamin B6, vitamin E). Our own experience of 12 patients with tardive dystonia showed the effeciency of local injections of botulinum toxin.

Valbenazine for the Treatment of Adults with Tardive Dyskinesia

PURPOSE OF REVIEW

This a comprehensive review of the literature regarding the use of Valbenazine in treating tardive dyskinesia. A primarily oral movement disorder induced by chronic exposure to certain classes of medications, tardive dyskinesia is often resistant to many therapeutic approaches. This review presents the background, evidence, and indications for the use of Valbenazine as a treatment option for this condition.

RECENT FINDINGS

Tardive dyskinesia is a disorder arising from long-term exposure to medications that blocked dopamine receptors, primarily antipsychotics. It is characterized by abnormal movements of the oral-buccal-lingual structures as well as associated pain and hypertrophy. Simply stopping the use of the dopamine blocking agents effectively alleviates the symptoms but is not always reliable hence the need for another therapeutic approach.Valbenazine is thought to function as a highly selective inhibitor of the VMAT2 vesicular monoamine transporter resulting in decreased availability of dopamine in the presynaptic cleft. This leads to decreased dopaminergic activation of the striatal motor pathway. The FDA approved Valbenazine in 2017 to treat tardive dyskinesia in adults and needs to be evaluated with existing therapeutic approaches.

SUMMARY

The chronic use of dopamine receptor blocking agents, most commonly antipsychotics, can lead to a movement disorder called tardive dyskinesia. Once symptom onset has occurred, these movement abnormalities can persist for years to permanently, depending on the speed and effectiveness of treatment. Valbenazine is a relatively newer option for the treatment of tardive dyskinesia in adults. Compared to other pharmaceutical agents, it is more selective and has limited toxicities making it an effective treatment regimen. However, further research, including additional direct comparison studies, should be conducted to fully evaluate this drug's usefulness.

Dystonia and leveraging oral pharmacotherapy

Dystonia is a clinically diverse disorder, characterized by sustained or intermittent muscle contractions causing abnormal and often repetitive movements and/or postures. Accurate clinical diagnosis is tantamount to effective dystonia management. Current guidelines in the treatments of dystonia, including oral therapy, are prescribed to improve symptoms and to restore functional capacity. Identifying treatable causes from co-existing phenomenologies is relevant to provide the most optimal and disease-specific medications. In other forms of dystonia, genetic factors may affect outcome. Moreover, proper selection of patients, early initiation of medications and customized drug titration are keys to increasing the chances of success when using oral therapies for dystonia. Treatment of dystonia primarily involves agents that target dopamine and acetylcholine receptors. Other drugs used include benzodiazepines, baclofen, antiepileptics, some antipsychotics drugs and antihistamine, with different levels of evidence of effectiveness. Unfortunately, most of the widely used drugs have low levels of evidence and are primarily based on anecdotal experiences. Finally, other adjunctive therapeutic strategies are often necessary to complement oral therapy.

Movement disorders in psychiatric patients

The observability of movement gives it advantages when trying to draw connections between brain and mind. Disturbed motor function pervades schizophrenia, though it is difficult now to subtract the effects of antipsychotic treatment. There is evidence from patients never exposed to these drugs that dyskinesia and even parkinsonism are to some degree innate to schizophrenia. Tardive dyskinesia and drug-induced parkinsonism are the most common movement disorders encountered in psychiatric practice. While D2 dopamine receptor blockade is a causative factor, both conditions defy straightforward neurochemical explanation. Balanced against the need to manage schizophrenic symptoms, neither prevention nor treatment is easy. Of all disorders classified as psychiatric, catatonia sits closest to organic neurology on the neuropsychiatric spectrum. Not only does it occur in the setting of unequivocally organic cerebral disease, but the alterations of consciousness it produces have ‘organic’ qualities even when the cause is psychiatric. No longer considered a subtype of schizophrenia, catatonia is defined by syndromic features based on motor phenomenology. Both severe depression and obsessive-compulsive disorder may be associated with ‘soft’ extrapyramidal signs that resemble parkinsonian bradykinesia. As functional neuroimaging studies suggest, movement and psychiatric disorders involve the same network connections between the basal ganglia and the cerebral cortex.

How and when to treat the most common adverse effects of antipsychotics: Expert review from research to clinical practice

OBJECTIVE

As most treatment guidelines for antipsychotics focus on clinical efficacy, we will instead focus on adverse effects and how to manage them. In this review, we aim to provide an up-to-date clinical resource for providers who prescribe antipsychotics and have included here "what's new" and "what to do" for numerous antipsychotic-induced adverse effects.

METHODS

A review was performed of relevant literature, studies, randomized clinical trials, and systematic reviews. This information was combined with the clinical experience of the authors to formulate a practical guide for treating adverse effects of antipsychotics with an emphasis on metabolic and movement disorder adverse effects and brief mention of some others (sedation and sexual dysfunction).

CONCLUSIONS

Antipsychotics are an integral part of psychiatric care and are often prescribed lifelong. When choosing an antipsychotic, special consideration must be given to adverse effects which have an undeniable impact on quality of life and can often be the deciding factor in patients' medication compliance. While patients may respond well to one specific medication, they may still experience adverse effects that lead them to discontinue it or switch to a more tolerable but less effective option. However, strategies do exist for managing and treating adverse effects, especially metabolic and movement adverse effects, allowing better personalization of antipsychotic choice.

Amantadine: reappraisal of the timeless diamond-target updates and novel therapeutic potentials

The aim of the current review was to provide a new, in-depth insight into possible pharmacological targets of amantadine to pave the way to extending its therapeutic use to further indications beyond Parkinson's disease symptoms and viral infections. Considering amantadine's affinities in vitro and the expected concentration at targets at therapeutic doses in humans, the following primary targets seem to be most plausible: aromatic amino acids decarboxylase, glial-cell derived neurotrophic factor, sigma-1 receptors, phosphodiesterases, and nicotinic receptors. Further three targets could play a role to a lesser extent: NMDA receptors, 5-HT3 receptors, and potassium channels. Based on published clinical studies, traumatic brain injury, fatigue [e.g., in multiple sclerosis (MS)], and chorea in Huntington's disease should be regarded potential, encouraging indications. Preclinical investigations suggest amantadine's therapeutic potential in several further indications such as: depression, recovery after spinal cord injury, neuroprotection in MS, and cutaneous pain. Query in the database http://www.clinicaltrials.gov reveals research interest in several further indications: cancer, autism, cocaine abuse, MS, diabetes, attention deficit-hyperactivity disorder, obesity, and schizophrenia.

Recognition and Treatment of Tardive Dyskinesia in Individuals with Intellectual Disability

Individuals with intellectual disability (ID) commonly suffer from comorbid psychiatric and behavioral disorders that are frequently treated by antipsychotic medications. All individuals exposed to first- and second/third- generation antipsychotics are at risk for developing tardive dyskinesia (TD), characterized by abnormal, involuntary movements of the mouth/tongue/jaw, trunk, and extremities. TD can be highly disruptive for affected individuals and their caregivers, causing embarrassment, isolation, behavioral disturbances, and reduced functioning and quality of life. Information on TD incidence in individuals with ID is limited, but 2 small US studies reported TD prevalence rates of 42-45% in inpatients with ID. The safety and efficacy of vesicular monoamine transporter type 2 (VMAT2) inhibitors approved for treatment of TD in adults have been demonstrated in multiple clinical trials, but they excluded individuals with ID. Clinical characteristics and treatment outcomes of 5 adults (aged 28-63 years) with mild-to-severe ID and TD are presented, illustrating TD symptoms before/after treatment. All individuals had multiple comorbid psychiatric, behavioral, and other medical conditions, history of antipsychotic exposure, and abnormal movements affecting the tongue/mouth/jaw (n = 5), upper extremities (n = 5), lower extremities (n = 3), and trunk (n = 2), resulting in diminished ability to speak (n = 2), ambulate (n = 3), and perform activities of daily living (n = 3). Treatment with valbenazine resulted in meaningful improvements in TD symptoms and improved daily functioning, demeanor, and social/caregiver interactions. Given the high likelihood of antipsychotic exposure in the ID population, it is appropriate to screen for TD at every clinical visit through careful monitoring for abnormal movements and questioning the individual/caregiver regarding abnormal movements or TD-related functional impairments (i.e., speaking, swallowing, eating, ambulating, and social functioning). In this study, 5 individuals with ID and TD received once-daily valbenazine and experienced marked improvement in TD symptoms and daily functioning, resulting in increased quality of life for affected individuals and caregivers.

Neurobiological mechanisms associated with antipsychotic drug-induced dystonia

Dystonia is by far the most intrusive and invalidating extrapyramidal side effect of potent classical antipsychotic drugs. Antipsychotic drug-induced dystonia is classified in both acute and tardive forms. The incidence of drug-induced dystonia is associated with the affinity to inhibitory dopamine D2 receptors. Particularly acute dystonia can be treated with anticholinergic drugs, but the tardive form may also respond to such antimuscarinic treatment, which contrasts their effects in tardive dyskinesia. Combining knowledge of the pathophysiology of primary focal dystonia with the anatomical and pharmacological organization of the extrapyramidal system may shed some light on the mechanism of antipsychotic drug-induced dystonia. A suitable hypothesis is derived from the understanding that focal dystonia may be due to a faulty processing of somatosensory input, so leading to inappropriate execution of well-trained motor programmes. Neuroplastic alterations of the sensitivity of extrapyramidal medium-sized spiny projection neurons to stimulation, which are induced by the training of specific complex movements, lead to the sophisticated execution of these motor plans. The sudden and non-selective disinhibition of indirect pathway medium-sized spiny projection neurons by blocking dopamine D2 receptors may distort this process. Shutting down the widespread influence of tonically active giant cholinergic interneurons on all medium-sized spiny projection neurons by blocking muscarinic receptors may result in a reduction of the influence of extrapyramidal cortical-striatal-thalamic-cortical regulation. Furthermore, striatal cholinergic interneurons have an important role to play in integrating cerebellar input with the output of cerebral cortex, and are also targeted by dopaminergic nigrostriatal fibres affecting dopamine D2 receptors.

Resolution of tardive tremor after bilateral subthalamic nucleus deep brain stimulation placement

Background:

Tardive tremor (TT) is an underrecognized manifestation of tardive syndrome (TS). In our experience, TT is a rather common manifestation of TS, especially in a setting of treatment with aripiprazole, and is a frequent cause of referrals for the evaluation of idiopathic Parkinson disease. There are reports of successful treatment of tardive orofacial dyskinesia and dystonia with deep brain stimulation (DBS) using globus pallidus interna (GPi) as the primary target, but the literature on subthalamic nucleus (STN) DBS for tardive dyskinesia (TD) is lacking. To the best of our knowledge, there are no reports on DBS treatment of TT.

Case Description:

A 75-year-old right-handed female with the medical history of generalized anxiety disorder and major depressive disorder had been treated with thioridazine and citalopram from 1980 till 2010. Around 2008, she developed orolingual dyskinesia. She was started on tetrabenazine in June 2011. She continued to have tremors and developed Parkinsonian gait, both of which worsened overtime. She underwent DBS placement in the left STN in January 2017 with near-complete resolution of her tremors. She underwent right STN implantation in September 2017 with similar improvement in symptoms.

Conclusion:

While DBS-GPi is the preferred treatment in treating oral TD and dystonia, DBS-STN could be considered a safe and effective target in patients with predominating TT and/or tardive Parkinsonism. This patient saw a marked improvement in her symptoms after implantation of DBS electrodes, without significant relapse or recurrence in the years following implantation.

Prescription of Anticholinergics in Tardive Syndromes: A "Dual Center" Survey among Psychiatrists

Methods

We assessed the attitude of two groups of psychiatrists (practicing in Italy and Thailand) towards the prescription of anticholinergics by a short online survey consisting of four questions. A total of one hundred questionnaires were sent out (50 in Italy and 50 in Thailand), and 42 psychiatrists responded to the survey.

Results

When comparing the two cohorts, the difference, both for age and years of practice, was statistically significant (p < 0.00001 and p < 0.0001, respectively), with Thai psychiatrists being younger and with less time in practice as specialists. The results from the survey showed that the prescription of anticholinergic drugs at the beginning of the antipsychotic treatment was used by 5 psychiatrists (20.0%) of the Italian cohort and by 1 (5.9%) of the Thai cohort. Regarding the Italian psychiatrists who did not prescribe anticholinergics concomitantly with neuroleptics, we found that 5 (25.0%) of them had prescribed anticholinergics in the past but had abandoned this practice, while 15 (93.7%) of the Thai psychiatrists who did not prescribe anticholinergics at the moment of the survey answered that they had prescribed these drugs in the past.

Conclusion

According to this preliminary survey, the practice to use anticholinergics as a treatment for tardive syndromes is still relatively common, particularly in psychiatrists of the older generation, but seemingly in decline over the years.

Tardive syndrome: An update and mini-review from the perspective of phenomenology

Tardive syndrome (TS) is a group of movement disorders caused by the long-term use of dopamine receptor blocking agents. The phenotypic presentation of TS is diverse, ranging from the most well-characterized symptom of tardive dyskinesia to other symptoms, including dystonia, akathisia, myoclonus, parkinsonism, tremor, and tics. These tardive symptoms are distinct not only in their phenomenology but also in their clinical outcomes. However, our knowledge of the pathophysiology and management of TS is almost exclusively based on tardive dyskinesia. First-generation antipsychotics have a higher risk of inducing TS and have largely been replaced by second-generation antipsychotics with a lower risk of TS. However, patients with off-label use of second-generation antipsychotics are still at risk of developing TS. Thus, the management of TS remains a challenging and important issue for physicians. In this review, we update the information on the epidemiology, phenomenology, and treatment of TS from the perspective of the specific form of TS.

Recent Advances in the Pharmacology of Tardive Dyskinesia

Tardive dyskinesia (TD) is a syndrome of abnormal involuntary movements that follows treatment with dopamine D2-receptor antagonists. Recent approval of vesicular monoamine transporter-2 (VMAT2) inhibitors offers hope for reducing the impact of TD. Although these drugs represent a significant advance in patient care and a practical step forward in providing relief for patients with TD, understanding of the pharmacology of TD that could inform future research to prevent and reverse TD remains incomplete. This review surveys evidence for the effectiveness of VMAT2 inhibitors and other agents in the context of theories of pathogenesis of TD. In patients for whom VMAT2 inhibitors are ineffective or intolerable, as well as for extending therapeutic options and insights regarding underlying mechanisms, a review of clinical trial results examined as experimental tests of etiologic hypotheses is worthwhile. There are still compelling reasons for further investigations of the pharmacology of TD, which could generate alternative preventive and potentially curative treatments. Finally, benefits from novel drugs are best realized within an overall treatment strategy addressing the condition and needs of individual patients.

Deutetrabenazine for treatment of involuntary movements in patients with tardive dyskinesia

Introduction: Tardive dyskinesia (TD) is a hyperkinetic movement disorder that arises as a complication of exposure to dopamine receptor blocking agents. Vesicular monoamine transporter type 2 (VMAT2) inhibitors reduce dyskinesia by decreasing transport of monoamines, including dopamine, into presynaptic vesicles, leaving unpackaged dopamine to be metabolized by monoamine oxidase. Deutetrabenazine was adapted from an earlier VMAT2 inhibitor, tetrabenazine, by substituting three deuterium isotopes in place of three hydrogen isotopes at the site of metabolic degradation to improve upon the pharmacokinetics of the parent compound. Areas covered: The authors reviewed the pivotal trials examining the safety and efficacy of deutetrabenazine, as well as long-term data from an open-label extension. Also reviewed were posters and oral presentations, as well as information from the product label and the United States Food and Drug Administration. Expert opinion: Deutetrabenazine is effective at decreasing dyskinesia in TD, but drug selection and cost-effectiveness between existing VMAT2 inhibitors are evolving areas of study. Other areas of investigation include novel anti-dyskinetic agents and use of deep brain stimulation.

Valbenazine and deutetrabenazine: Vesicular monoamine transporter 2 inhibitors for tardive dyskinesia

PURPOSE

The purpose of this review is to summarize the current evidence for valbenazine and deutetrabenazine use for the treatment of tardive dyskinesia (TD).

SUMMARY

A literature search was conducted to gather relevant data regarding the use of valbenazine and deutetrabenazine for TD management. PubMed, MEDLINE, and ClinicalTrials.gov were searched using the following keywords and MeSH terms: valbenazine, deutetrabenazine, tardive dyskinesia, VMAT2 inhibitors, and vesicular monoamine transporter 2 inhibitors. Randomized, double-blind, placebo-controlled trials and meta-analyses published in English from April 2015 to August 2019 were included. Valbenazine 40-80 mg and deutetrabenazine 12-36 mg per day have been evaluated for the treatment of TD. Abnormal Involuntary Movement Scale (AIMS) scores decline similarly (by 2-5 points) with use of either agent. AIMS response rates, defined by a 50% decline in symptoms, range from 33% to 50%. Both agents are well tolerated, with somnolence and akathisia reported most frequently (at low rates). Agent selection may be guided by manufacturer labeling recommendations for special populations and cost considerations.

CONCLUSIONS

Valbenazine and deutetrabenazine were demonstrated to be effective in decreasing AIMS scores and were well tolerated in randomized controlled trials. These treatments may be considered as a next-line option when traditional strategies are not feasible or are ineffective. Head-to-head studies are warranted to decipher if either agent is preferable in terms of efficacy or tolerability.

A Focused Update on Tardive Dyskinesia

Tardive dyskinesia (TD) is a delayed and potentially irreversible motor complication following chronic exposure to centrally acting dopamine receptor antagonists, mainly of the class of antipsychotics drugs. New generations of antipsychotic drugs reduced its mean prevalence to 20%, but it continues to mar the drug experience and social integration in a significant fraction of patients. The underlying molecular cascade remains elusive, explaining in part why TD management is so often difficult. Protocol variations between experimental laboratories and inter-species differences in the biological response to antipsychotic drugs have added layers of complexity. The traditional dopamine D2 receptor supersensitivity hypothesis was revisited in an experimental nonhuman primate model. Findings in the striatum revealed a strong upregulation of D3, not D2, receptors specific to dyskinetic animals, and indirect evidence suggestive of a link between overactivation of glycogen synthase kinase-3β signaling and TD. New effective vesicular monoamine transporter type 2 inhibitors alleviating TD have been approved in the USA. They were integrated to an emerging stepwise treatment algorithm for troublesome TD, which also includes consideration for changes in the current antipsychotic drug regimen and recognition of potentially aggravating factors such as anticholinergic co-medications. These advances may benefit TD.

Drug-induced dyskinesias, can they be prevented?

Introduction: Dyskinesia is a symptom complex in the form of involuntary, repetitive movements of lips, lower jaw, tongue, less often the trunk and limbs. Despite the use of newer drugs in treatment neuroleptics, dyskinesia has not ceased to be a clinical problem.

Method: The work is based on a research review for which the Google Scholar database was used as well PubMed. The search range was limited to 2008-2020. We have included descriptive publications tardive dyskinesia only as a consequence of antipsychotic medications.

Material: We present the use of tetrabenazine analogues, deep brain stimulation, neuroleptics, benzodiazepines and botulinum toxin in late-suffering patients drug-induced dyskinesias, which may indicate an improvement in your health.

Discussion: The first method of treating tardive dyskinesia are withdrawal antipsychotic medications, but for many patients this is impossible. Valbenazine and Deep Brain Stimulation are the most effective in treating Tardive Dyskinesia.

Conclusions: There are not enough studies with the highest reliability to create unequivocal recommendations in the treatment of drug-induced tardive dyskinesia.

Management of Tardive Syndrome: Medications and Surgical Treatments

Tardive syndrome (TS) is an iatrogenic, often persistent movement disorder caused by drugs that block dopamine receptors. It has a broad phenotype including movement (orobuccolingual stereotypy, dystonia, tics, and others) and nonmotor features (akathisia and pain). TS has garnered increased attention of late because of the Food and Drug Administration approval of the first therapeutic agents developed specifically for this purpose. This paper will begin with a discussion on pathogenesis, clinical features, and epidemiology. However, the main focus will be treatment options currently available for TS including a suggested algorithm based on current evidence. Recently, there have been significant advances in TS therapy, particularly with the development of 2 new vesicular monoamine transporter type 2 inhibitors for TS and with new data on the efficacy of deep brain stimulation. The discussion will start with switching antipsychotics and the use of clozapine monotherapy which, despite the lack of higher-level evidence, should be considered for the treatment of psychosis and TS. Anti-dyskinetic drugs are separated into 3 tiers: 1) vesicular monoamine transporter type 2 inhibitors, which have level A evidence, are approved for use in TS and are recommended first-choice agents; 2) drugs with lower level of evidence for efficacy including clonazepam, Ginkgo biloba, and amantadine; and 3) drugs that have the potential to be beneficial, but currently have insufficient evidence including levetiracetam, piracetam, vitamin B6, melatonin, baclofen, propranolol, zolpidem, and zonisamide. Finally, the roles of botulinum toxin and surgical therapy will be examined. Current therapies, though improved, are symptomatic. Next steps should focus on the prevention and reversal of the pathogenic process.

The role of glutamate receptors and their interactions with dopamine and other neurotransmitters in the development of tardive dyskinesia: preclinical and clinical results

Tardive dyskinesia is a serious, disabling, movement disorder associated with the ongoing use of antipsychotic medication. Current evidence regarding the pathophysiology of tardive dyskinesia is mainly based on preclinical animal models and is still not completely understood. The leading preclinical hypothesis of tardive dyskinesia development includes dopaminergic imbalance in the direct and indirect pathways of the basal ganglia, cholinergic deficiency, serotonin receptor disturbances, neurotoxicity, oxidative stress, and changes in synaptic plasticity. Although, the role of the glutamatergic system has been confirmed in preclinical tardive dyskinesia models it seems to have been neglected in recent reviews. This review focuses on the role and interactions of glutamate receptors with dopamine, acetylcholine, and serotonin in the neuropathology of tardive dyskinesia development. Moreover, preclinical and clinical results of the differentiated effectiveness of N-methyl-D-aspartate (NMDA) receptor antagonists are discussed with a special focus on antagonists that bind with the GluN2B subunit of NMDA receptors. This review also presents new combinations of drugs that are worth considering in the treatment of tardive dyskinesia.