Treatment of Tardive Dystonia Induced by Antipsychotics, Old and New

A Low Clozapine Dose Improved Refractory Tardive Dystonia without Exacerbating Psychiatric Symptoms: A Case Report

Clozapine is recommended for patients with schizophrenia and tardive dystonia (TD); however, the appropriate dose remains unclear. In this case, a low dose (150 mg/day) of clozapine improved refractory TD and further ameliorated psychiatric symptoms. Herein, we report on a 41-year-old female with schizophrenia and TD who was treated with a low clozapine dose. After eight weeks of continuous clozapine at 150 mg/day (16 weeks after clozapine initiation), her TD dramatically improved, and her psychiatric symptoms were relieved. Low clozapine doses could ameliorate refractory TD. However, this effect might require up to several weeks. Clinicians should be patient unless they consider it better to increase the clozapine dose.

The psychopharmacology of catatonia, neuroleptic malignant syndrome, akathisia, tardive dyskinesia, and dystonia

Although highly prevalent, motor syndromes in psychiatry and motor side effects of psychopharmacologic agents remain understudied. Catatonia is a syndrome with specific motor abnormalities that can be seen in the context of a variety of psychiatric and somatic conditions. The neuroleptic malignant syndrome is a lethal variant, induced by antipsychotic drugs. Therefore, antipsychotics should be used with caution in the presence of catatonic signs. Antipsychotics and other dopamine-antagonist drugs can also cause motor side effects such as akathisia, (tardive) dyskinesia, and dystonia. These syndromes share a debilitating impact on the functioning and well-being of patients. To reduce the risk of inducing these side effects, a balanced and well-advised prescription of antipsychotics is of utmost importance. Clinicians should be able to recognize motor side effects and be knowledgeable of the different treatment modalities.

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

BACKGROUND

Management of tardive syndromes (TS) is challenging, with only a few evidence-based therapeutic algorithms reported in the American Academy of Neurology (AAN) guideline in 2013.

OBJECTIVE

To update the evidence-based recommendations and provide a practical treatment algorithm for management of TS by addressing 5 questions: 1) Is withdrawal of dopamine receptor blocking agents (DRBAs) an effective TS treatment? 2) Does switching from typical to atypical DRBAs reduce TS symptoms? 3) What is the efficacy of pharmacologic agents in treating TS? 4) Do patients with TS benefit from chemodenervation with botulinum toxin? 5) Do patients with TS benefit from surgical therapy?

METHODS

Systematic reviews were conducted by searching PsycINFO, Ovid MEDLINE, PubMed, EMBASE, Web of Science and Cochrane for articles published between 2012 and 2017 to identify new evidence published after the 2013 AAN guidelines. Articles were classified according to an AAN 4-tiered evidence-rating scheme. To the extent possible, for each study we attempted to categorize results based on the description of the population enrolled (tardive dyskinesia [TD], tardive dystonia, tardive tremor, etc.). Recommendations were based on the evidence.

RESULTS AND RECOMMENDATIONS

New evidence was combined with the existing guideline evidence to inform our recommendations. Deutetrabenazine and valbenazine are established as effective treatments of TD (Level A) and must be recommended as treatment. Clonazepam and Ginkgo biloba probably improve TD (Level B) and should be considered as treatment. Amantadine and tetrabenazine might be considered as TD treatment (Level C). Pallidal deep brain stimulation possibly improves TD and might be considered as a treatment for intractable TD (Level C). There is insufficient evidence to support or refute TS treatment by withdrawing causative agents or switching from typical to atypical DRBA (Level U).

Deep Brain Stimulation for the Dystonias: Evidence, Knowledge Gaps, and Practical Considerations

BACKGROUND

Deep brain stimulation (DBS) of the globus pallidus internus (GPi-DBS) is among the most effective treatment options for dystonias. Because the term "dystonia" is defined by a characteristic phenomenology of involuntary muscle contractions, which may present with a large clinical and pathogenetic heterogeneity, decision making for or against GPi-DBS can be difficult in individual patients.

METHODS

A search of the PubMed database for research and review articles, focused on "deep brain stimulation" and "dystonia" was used to identify clinical trials and to determine current concepts in the surgical management of dystonia. Patient selection in previous studies was recategorized by the authors using the new dystonia classification put forward by a consensus committee of experts in dystonia research. The evidence and knowledge gaps are summarized and commented by the authors taking into account expert opinion and personal clinical experience for providing practical guidance in patient selection for DBS in dystonia.

RESULTS

The literature review shows that pallidal deep brain stimulation is most effective in patients with isolated dystonia irrespective of the underlying etiology. In contrast, patients with combined dystonias are less likely to benefit from DBS, because the associated neurological symptoms (e.g., hypotonia or ataxia), with the exception of myoclonus, do not respond to pallidal neurostimulation.

CONCLUSIONS

It is important to recognize the clinical features of dystonia, because the distinction between isolated and combined dystonia syndromes may predict the treatment response to pallidal deep brain stimulation. The aim of this review is to help guide clinicians with advising patients about deep brain stimulation therapy for dystonia and refering appropriate candidates to surgical centers.

Medical treatment of dystonia

Therapeutic strategies in dystonia have evolved considerably in the past few decades. Three major treatment modalities include oral medications, botulinum toxin injections and surgical therapies, particularly deep brain stimulation. Although there has been a tremendous interest in the later two modalities, there are relatively few recent reviews of oral treatment. We review the medical treatment of dystonia, focusing on three major neurotransmitter systems: cholinergic, GABAergic and dopaminergic. We also provide a practical guide to medication selection, therapeutic strategy and unmet needs.

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.

The Symptomatic Treatment of Acquired Dystonia: A Systematic Review

Background

Acquired dystonia is caused by an acquired or exogenous event. Although the therapeutic armamentarium used in clinical practice is more or less similar to that used for inherited or idiopathic dystonia, formal proof of the efficacy of these interventions in acquired dystonia is lacking.

Methods

The authors attempt to provide a comprehensive and systematic review of the current evidence for medical and allied health care treatment strategies in acquired dystonias. The PubMed, Cochrane Library, MEDLINE, Web of Science, PiCarta, and PsycINFO databases were searched up to December 2015, including randomized controlled trials, patient-control studies, and case series or single case reports containing a report on clinical outcome.

Results

There are level 3 practice recommendations for botulinum toxin injections and globus pallidus pars interna deep brain stimulation for tardive dystonia and dystonic cerebral palsy as well as intrathecal baclofen for dystonic cerebral palsy. There are insufficient and conflicting data on the effect (vs. the hazard) of other pharmacological interventions, and limited work has been done on other forms of neurostimulation and allied health care. Because no class A1 or A2 studies were identified, level 1 or 2 practice recommendations could not be deducted for a specific treatment intervention.

Conclusions

To improve the current medical and allied health care treatment options for patients with acquired dystonia, high-quality trials that examine the efficacy of therapies need to be performed.