Neuroleptically induced dystonia in Huntington's disease: a case report

A systematic review of the treatment studies in Huntington's disease since 1990

Huntington's disease (HD) is an autosomal dominant, inherited, neuropsychiatric disease that gives rise to progressive motor, cognitive and behavioural symptoms. Current drug therapy has no effect on the progression of disability, and the need for any pharmacological treatment should be carefully considered. Hyperkinesias and psychiatric symptoms may respond well to pharmacotherapy, but neuropsychological deficits and dementia remain untreatable. Pharmacological intervention in the treatment of the movement disorder of HD is aimed at restoring the balance of neurotransmitters in the basal ganglia. A surprising amount of current drug therapy of HD in clinical practice is based on studies published before 1990. The authors conducted a systematic review of pharmacological therapy in HD using the available papers that were published between 1990 and 2006.

Huntington's disease: present treatments and future therapeutic modalities

Huntington's disease (HD) is a devastating neuropsychiatric disorder for which therapeutic interventions have been rather fruitless to date, except in a slight symptomatic relief. Even the discovery of the gene related to HD in 1993 has not effectively advanced treatments. This article is essentially a review of available double-blind, placebo-controlled trials of therapy for this condition which also includes relevant open label trials. Unfortunately, HD research has tended to concentrate on the motor aspects of the disorder, whereas the major problems are behavioural (e.g. dementia, depression, psychosis), and the chorea is often least relevant in terms of management. We conclude that there is definitely poor evidence in management of HD. The analysis of the 24 best studies fails to result in a treatment recommendation of clinical relevance. Based on data of open-label studies, or even case reports, we recommend riluzole, olanzapine and amantadine for the treatment of the movement disorders associated with HD, selective serotonin reuptake inhibitors and mirtazapine for the treatment of depression, and atypical antipsychotic drugs for HD psychosis and behavioural problems. Moreover, adjuvant psychotherapy, physiotherapy and speech therapy should be applied to supply the optimal management. Finally, some cellular mechanisms are discussed in this paper because they are essential for future neuroprotective modalities, such as minocycline, unsaturated fatty acids or riluzole.

Zotepine in Huntington's disease

The authors report a patient with Huntington's disease (HD) presenting with severe chorea. The motor scale of the unified HD rating scale (UHDRS-I) revealed 81 points. Motor function clearly improved with zotepine, until she reached an UHDRS-I of 34 points on day 7 of treatment. The patient was stable for at least 12 weeks. The improvement includes all seven categories of the UHDRS-I, especially chorea, gait and oral function. This is the first description of zotepine in HD. Our findings suggest that zotepine is useful in the treatment of HD chorea. Controlled trials of its use in HD would be welcome.

Dystonia in Huntington's disease: prevalence and clinical characteristics

BACKGROUND

The prevalence and clinical characteristics of dystonia in Huntington's disease (HD) have not been formally assessed.

OBJECTIVES

To study (1) the prevalence of dystonia in HD in a clinic population, (2) the clinical features of dystonia, and (3) clinical correlates of dystonia (for example, age, disease duration).

METHODS

Patients with HD attending the HD Center at the New York State Psychiatric Center were administered the Unified HD Rating Scale and underwent a standardized 5.5-minute videotaped examination. Two neurologists reviewed the videotaped examination and rated the severity and constancy of dystonia, calculating a total dystonia score for each patient.

RESULTS

Prevalence of dystonia of any severity was 95.2%. Twenty-four of 42 (57.1%) had dystonia in at least one body region that was moderate and present more than half of the time, and seven of 42 (16.7%) had dystonia that was severe and constant. The most prevalent types of dystonia were internal shoulder rotation (64.3%), sustained fist clenching (47.1%), excessive knee flexion (42.9%), and foot inversion (42.9%). In 37 of 42 (88.1%) patients, there were more than two types of dystonia, and in the average patient, three to four types of dystonia. The mean severity was between 1 (mild) and 2 (moderate), and the mean constancy was between 2 (present less than half of the time) and 3 (present more than half of the time). Multivariate linear regression revealed that disease duration (p = 0.0005) and taking an antidopaminergic agent (p = 0.03) were positively associated with the total dystonia score.

CONCLUSIONS

The majority of patients in this HD clinic exhibited some dystonia. The dystonia was present in several body regions and manifested by a variety of movements and postures not typical of idiopathic torsion dystonia. The dystonia was not bothersome to most patients, and its severity was a function of disease duration and use of an antidopaminergic agent.

Clozapine versus placebo in Huntington's disease: a double blind randomised comparative study

OBJECTIVES

To establish the effect of the atypical neuroleptic clozapine on chorea, voluntary motor performance, and functional disability in patients with Huntington's disease.

METHODS

Thirty three patients with Huntington's disease participated in a double blind randomised trial. A maximum of 150 mg/day clozapine or placebo equivalent was given for a period of 31 days. Assessments were performed in the week before and at the last day of the trial. Chorea was scored using the abnormal involuntary movement scale (AIMS), the chorea score of the unified Huntington's disease rating scale (UHDRS), and judgement of video recordings. Voluntary motor performance was assessed using the UHDRS motor scale. Patients and their partners completed a questionnaire regarding functional disability. Twelve patients already used other neuroleptic medication, which was kept unchanged during the trial period. Results of neuroleptic naive and neuroleptic treated patients were analysed separately.

RESULTS

Clozapine tended to reduce chorea in neuroleptic naive patients only (AIMS); improvement seemed more pronounced in patients receiving higher doses of clozapine. Other measures of chorea (UHDRS chorea score, video ratings) showed no improvement. Clozapine had no beneficial effect on chorea in patients already receiving neuroleptic medication. Voluntary motor performance did not improve with clozapine. Neuroleptic naive patients reported aggravation of functional disability, possibly reflecting the frequent occurrence of side effects. Adverse reactions forced trial termination in six patients and dose reduction in another eight, and consisted mainly of drowsiness, fatigue, anticholinergic symptoms, and walking difficulties.

CONCLUSIONS

Clozapine has little beneficial effect in patients with Huntington's disease, although individual patients may tolerate doses high enough to reduce chorea. Because adverse reactions are often encountered, clozapine should be used with restraint in this patient group.