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.