The causes of sporadic and ‘senile’ chorea

Background: Although 'senile' chorea is commonly listed in the differential diagnosis of chorea, the condition is poorly defined. Indeed, the existence of such an entity is debated. There are few contemporary prospective studies of sporadic chorea in the elderly. Methods: Detailed prospective study of patients presenting with undiagnosed chorea over a three year period to a Movement Disorder Clinic. Results: Twelve patients, aged 50 to 89 years, were identified. The final diagnoses were Huntington's disease, confirmed on genetic testing in six, antiphospholipid antibody syndrome in two, and hypocalcaemia, tardive dyskinaesia and basal ganglia calcification in each of the three remaining cases. Only one patient remained undiagnosed despite extensive investigation. Conclusions: The majority of patients with 'senile' chorea actually have Huntington's disease even in the absence of a family history. Rarer causes of chorea still need to be considered in the elderly when Huntington's disease has been excluded by DNA analysis.