Turcano P, et al. - By using the 1991–2010 population-based, parkinsonism-incident cohort of Olmsted County, MN (n = 669), obtained by the Rochester Epidemiology Project, authors analyzed dyskinesia frequency due to levodopa treatment in subjects (median age of 74.1 years) with Parkinson disease (PD), treated by a Mayo Clinic neurologist. Three grades of dyskinesia were observed as mild, moderate and severe within 5 years of levodopa initiation. Marked improvement was recorded in 13 cases who underwent deep brain stimulation. Lewy body disease was verified in 7 autopsied cases during postmortem review. Mayo neurologists supporting levodopa were observed with a positive result in most cases. About 30% of the patients with PD were found affected by levodopa-induced dyskinesia.