Review article
Symptoms, pathogenesis and current pharmacological treatment of Huntington’s disease. European Huntington’s Disease Network

Huntington\'s disease (HD) is an autosomal-dominant, progressive neurodegenerative disorder with a characteristic phenotype, with incoordination, choreatic movements and dystonia. In addition, a variety of psychiatric and behavioural symptoms, along with cognitive decline, contribute significantly to the patient\'s disability. Usually, onset of symptoms is in middle age, when individuals with a mutated IT-15 gene have had children, but the disorder can manifest at any time between infancy and senescence. The modified huntingtin in HD, the product of the mutated IT-15 gene, results from an expanded CAG repeat leading to a polyglutamine strand of variable length at the N-terminus. Current opinions concerning the role of mutated huntingtin concrements in neurons plead against their neurotoxicity. The precise pathophysiological mechanisms of HD are poorly understood, but research in transgenic animal models of the disorder is providing insight into causative factors and potential aetiological treatments. Because there are no effective neuroprotective therapies that delay the progression of the disease, symptomatic treatment remains the basis of medical management. Several classes of medications have been used to ameliorate the various symptoms of HD, including typical and atypical neuroleptics, dopamine depleters, antidepressants, antiglutamatergic drugs, GABA agonists, antiepileptic medications, and botulinum toxin. The selected therapy must be adapted to the needs of each patient, minimizing the potential adverse effects. Centres of excellence arising in future from current European Huntington’s Disease Network (EHDN) Study Sites will take care of treatment of HD patients and gene carriers, and train doctors in HD treatment.