A statistical trial of subclassification for tardive dyskinesia

Drug-Induced Extrapyramidal Symptoms Scale of the Norwegian version: inter-rater and test-retest reliability

Background: The Drug-Induced Extrapyramidal Symptoms Scale (DIEPSS) is a multidimensional rating scale designed for the fast, easy and reliable assessment of extrapyramidal symptoms (EPSs) induced by antipsychotics. Aim: The aim of this study was to validate the level of inter-rater and test-retest reliability of the Norwegian translation of this scale. Methods: A total of 125 video clips showing a variety of or no signs of EPSs were used in the present study. The participants recorded were Japanese psychiatric patients receiving first- and/or second-generation antipsychotics. A total of 103 patients (47 males and 56 females), diagnosed with schizophrenia (n = 68) or mood disorders (n = 35) appeared in the video clips. Their mean age was 48.7 ± 16.3 years (range 18-80) at the time of video recording. Inter-rater agreement was assessed with five raters and test-retest reliability with three. Results: Inter-rater reliability analyses showed interclass correlation coefficients (ICCs) ranging from 0.74 to 0.93 for each individual item. Test-retest reliability analysed independently for each rater ranged from 0.71 to 0.96. Conclusions: Inter-rater and test-retest agreement exhibited satisfactory ICC levels above 0.70. The Norwegian version of the DIEPSS is a reliable instrument for the assessment of drug-induced EPSs.

Tardive dyskinesia and DRD3, HTR2A and HTR2C gene polymorphisms in Russian psychiatric inpatients from Siberia

BACKGROUND

Pharmacogenetics of tardive dyskinesia and dopamine D3 (DRD3), serotonin 2A (HTR2A), and 2C (HTR2C) receptors has been examined in various populations, but not in Russians.

PURPOSE

To investigate the association between orofaciolingual (TDof) and limb-truncal dyskinesias (TDlt) and Ser9Gly (DRD3), -1438G>A (HTR2A), and Cys23Ser (HTR2C) polymorphisms in Russian psychiatric inpatients from Tomsk, Siberia.

METHODS

In total, 146 subjects were included. Standard protocols were applied for genotyping. TDof and TDlt were assessed with AIMS items 1-4 and 5-7, respectively. Two-part model, logistic and log-normal regression analyses were applied to assess different variables (e.g., allele-carriership status, age, gender, and medication use).

RESULTS

TDlt, but not TDof, exhibited an association with Ser9Gly and Cys23Ser (with 9Gly and 23Ser alleles exhibiting opposite effects). However, -1438G>A was not associated with TDof and Dlt.

CONCLUSIONS

This is the first pharmacogenetic report on tardive dyskinesia in Russians. Subject to further replication, our findings extend and support the available data.

Pathway-based association analysis of genome-wide screening data suggest that genes associated with the gamma-aminobutyric acid receptor signaling pathway are involved in neuroleptic-induced, treatment-resistant tardive dyskinesia

OBJECTIVE

Neuroleptic-induced tardive dyskinesia (TD) is an involuntary movement disorder that develops in patients who have undergone long-term treatment with antipsychotic medications, and its etiology is unclear. In this study, a genome-wide association screening was done to identify the pathway(s) in which genetic variations influence susceptibility to neuroleptic-induced TD.

METHODS

Screening with Sentrix Human-1 Genotyping BeadChip (Illumina, San Diego, California, USA) was done for 50 Japanese schizophrenia patients with treatment-resistant TD and 50 Japanese schizophrenia patients without TD. A total of 40 573 single nucleotide polymorphisms that were not in linkage disequilibrium with each other and were located in the exonic and intronic regions of 13 307 genes were analyzed. After gene-based corrections, P values for allelic associations were subjected to canonical pathway-based analyses with Ingenuity Pathway Analysis software (Ingenuity Systems, Inc., Redwood City, California, USA).

RESULTS

Eight genes (ABAT, ALDH9A1, GABRA3, GABRA4, GABRB2, GABRAG3, GPHN, and SLC6A11) contained polymorphisms with gene-based corrected allelic P values of less than 0.05. They were aggregated significantly in 33 genes belonging to the gamma-aminobutyric acid (GABA) receptor signaling pathway (P=0.00007, corrected P=0.01). Associations were replicated in an independent sample of 36 patients with TD and 136 patients without TD for polymorphisms in SLC6A11 (GABA transporter 3) (P=0.0004 in the total sample), GABRB2 (beta-2 subunit of GABA-A receptor) (P=0.00007 in the total sample), and GABRG3 (gamma-3 subunit of GABA-A receptor) (P=0.0006 in the total sample).

CONCLUSION

The results suggest that the GABA receptor signaling pathway may be involved in genetic susceptibility to treatment-resistant TD, at least in a subgroup of Japanese patients with schizophrenia. The present results suggest that benzodiazepines may be considered as possible treatment option for TD.

Methamphetamine psychosis in which tardive dystonia was successfully treated with clonazepam

Reported herein is a case of methamphetamine psychosis in which tardive dystonia was treated successfully with clonazepam. The patient was a 69-year-old man who had taken methamphetamine habitually for approximately 40 years. Auditory hallucinations had developed 25 years previously, for which haloperidol had been prescribed. Tardive dystonia had developed in December 2005. Haloperidol was withdrawn and risperidone or olanzapine alone had been administered, but neither had improved the dystonic posture. However, when clonazepam was added, a gradual improvement in the dystonic posture became evident. Tardive dystonia is currently treated on a trial-and-error basis. Accumulation of further cases similar to the present one is very important for establishing an effective treatment.

Managing antipsychotic-induced acute and tardive dystonia

Antipsychotic-induced extrapyramidal adverse effects continue to be a serious problem in the treatment of psychotic disorders. While the pathophysiology of these adverse effects is not well understood, much recent research has focused on improving our ability to use available pharmacotherapy in the most effective and least toxic manner. Acute dystonic reactions only occur within the first days of antipsychotic treatment. They are often distressing and frightening for the patient and may even be dangerous. However, they can be effectively prevented or reversed with anticholinergics. Furthermore, the growing use of the new atypical antipsychotics will lead to a significant decrease in the rate of acute dystonic reactions. In contrast, tardive dystonia is a long-lasting menace in the course of antipsychotic treatment, for which there is no established therapy. Tardive dystonia is sometimes disabling or disfiguring and, like other tardive disorders, is potentially irreversible. Because, in most cases, patients need to continue taking the antipsychotic that has caused the adverse effect to prevent relapse of the mental illness, preventive measures are crucial. Antipsychotics should be prescribed only for patients affected by psychotic disorders, when definitely indicated and at the lowest effective dosage. The use of clozapine and other novel antipsychotic agents is also likely to represent an important step in the prevention and treatment of tardive dystonia. Compared with traditional antipsychotics, most of the new antipsychotics are characterised by a low acute extrapyramidal adverse effects liability and they also bring the hope of reducing the risk of tardive disorders. If tardive dystonia has occurred, switching to clozapine or another atypical antipsychotic and treatment with tetrabenazine, reserpine and botulinum toxin are possible options.

Current topics in tardive dyskinesia in Japan

This article reviews current topics in tardive dyskinesia (TD), a movement disorder associated with the prolonged use of neuroleptic agents, especially therapeutic and preventive strategies which have been or are now being studied in Japan. Tardive dyskinesia has become a major problem in the clinical psychiatric field since the early 1970s in Japan, lagging behind Western countries by more than 10 years. The average prevalence rate of TD has been estimated as 7.7% in Japan, while it has been reported in the English literature at around 15 to 20%. Clinical trials of treatments for TD have been or are now being performed in Japan with a number of novel compounds, such as ceruletide, meclofenoxate, and rolipram; however, no effective treatment has yet been established and measures to prevent TD have therefore been emphasized. These include (i) the development of new antipsychotic drugs which are free from TD, (ii) the identification of risk factors from prospective longitudinal studies, and (iii) the investigation of genetic variations that could act as a marker to identify especially vulnerable patients within the whole population of patients who need neuroleptic therapy.

Loss of striatal cholinergic neurons as a basis for tardive and L-dopa-induced dyskinesias, neuroleptic-induced supersensitivity psychosis and refractory schizophrenia

In the first section of this paper several aspects of tardive dyskinesia (TD) (clinical, epidemiological, pharmacological) are reviewed. We propose that this syndrome is not the consequence of dopamine receptor proliferation, but results from damage or degeneration of striatal cholinergic interneurons. We suggest that this cellular damage is caused by prolonged overactivation of these neurons, which occurs when they are released from dopaminergic inhibition following neuroleptic administration. Overactivity of central cholinergic systems during akinetic and motor retarded depression could be a contributory cause. The predisposition to L-DOPA-induced peak-dose dyskinesia in Parkinson's disease may depend on the same type of striatal neuronal loss. In the second part of the paper, the subject of supersensitivity psychosis and drug-resistant schizophrenia is reviewed. These two syndromes, are commonly associated with TD, have similar predisposing factors and pharmacology to TD, and are potentially persistent. We suggest that these conditions also result from degeneration of cholinergic striatal interneurons following chronic neuroleptic administration. The efficacy of clozapine for such treatment-refractory psychoses is explained in terms of its blockade of D-1 dopamine receptors. Other drugs effective against refractory psychoses (e.g. risperidone) are predicted to reduce activation at D-1 receptors.

Sub-syndromes of tardive dyskinesia and some clinical correlates

Syndromes of dyskinetic movements in subjects (N = 70) with chronic schizophrenia were investigated, using principal components analysis of AIMS ratings. Consonant with previous research, three discrete groupings were found, namely dyskinetic movements of lips-jaw-tongue, limb-truncal and facial movements. These were then related to demographic, psychological and movement disorder variables. The limb-truncal, but neither the lips-jaw-tongue nor facial movements components, were associated with negative symptoms and cognitive impairment.