<prompt> A 40-year-old man is brought to the doctor by his family for the rapid intellectual decline. Examination shows fast semi-purposive movements in hands. His father and grandfather had a similar illness. What is the diagnosis?Pre-senile DementiaLewy body dementiaCoicobasilar degenerationHuntington chorea  <response>: The fast semi-purposive movements - Chorea. With advancing age chorea reduces and dystonia, rigidity, and myoclonus appear. Huntingtons disease has an autosomal dominant pattern of inheritance . The intellectual decline is a common feature. Presenile dementia is seen in Downs syndrome Lewy body dementia presents with hallucinations, delusions, and dementia. Coicobasal degenerationAlien hand syndrome-Asymmetric dystonia, apraxia Loss of visuospatial skills, focal limb myoclonus 