Decades of delayed diagnosis in 4 levodopa-responsive young-onset monogenetic parkinsonism patients.

Background: We report 4 patients with young-onset monogenetic parkinsonism, each of whom was misdiagnosed with either a psychogenic movement disorder or chronic fatigue syndrome for 10 to 23 years after the onset of their first symptoms. Results: Once the diagnosis was eventually made, they all had a rapid and excellent response to levodopa, albeit with the early appearance of interdose dyskinesias in 3. Conclusions: We discuss possible reasons for the missed diagnosis despite the relentless progression of their motor handicap. DAT scanning supported the revised clinical diagnosis of parkinsonism. (C) 2011 Movement Disorder Society