The Sydney multicenter study of Parkinson's disease: The inevitability of dementia at 20 years

After 20 years follow-up of newly diagnosed patients with Parkinson's disease (PD), 100 of 136 (74%) have died. The mortality rate fell in the first 3 years of treatment, then rose compared to the general population, the standardized mortality ratio from 15 to 20 years reaching 3.1. Drug induced dyskinesia and end of dose failure were experienced by most patients, but the main current problems relate to the non-levodopa responsive features of the disease. Dementia is present in 83% of 20-year survivors. Dementia correlates with increasing age and probably reflects an interplay of multiple pathologies. Seventeen people with dementia had postmortems. Eight had diffuse Lewy bodies as the only cause of dementia,…

• MR
  Medical Research Council
• NH
  National Health and Medical Research Council