Parkinsons epidemiology: prevalence is 0.5-1 1-1.5 1.5-2 2-2.5( 0.5-1, 1-1.5, 1.5-2, 2-2.5 )% in the UK in >60 50 70 80( 60, 50, 70, 80 )'s. it is the second most common neurodegenerative disorder after alzeheimers. the mean age of onset is 45-60 50-65 55-70 60-75( 45-60, 50-65, 55-70, 60-75 ) but it can occur in people as young as 30 20 25 35( 30, 20, 25, 35 ). there are 120,000 100,000 80,000 140,000( 120,000, 100,000, 80,000, 140,000 ) people living with parkinsons in the UK.