title: Rate of clinical progression in Parkinson's disease. A prospective study.
abstract: Few prospective data on the clinical progression of Parkinson's disease (PD) in patient groups outside treatment trials in selected patients are available, and controversy exists on the rate of clinical disease progression with advancing disease. In this study, we investigated the rate of clinical progression of PD in a clinic-based sample of 145 patients over 1 year and in a community-based sample of 124 patients over 4 years. Depending on the sample and clinical scale used, mean deterioration of motor and disability scores ranged from 2.4 to 7.4% of the maximum possible score per year, and standard deviations indicated that there was considerable variability of progression rates between individuals. The progression of motor scores decreased with follow-up over 4 years and significantly decreased in more advanced disease stages. Deterioration of disability scores did not differ between disease stages; this may reflect the increasing rate of disease complications, which contribute to increasing disability in addition to motor impairment alone, in more advanced disease. Thus, motor fluctuations, hallucinations, depression, memory problems, and bladder symptoms were all reported more often at follow-up in the community-based sample (all P < 0.01), and dyskinesias, motor fluctuations, falls, and hallucinations were more common and cognitive and depression scores worse in higher disease stages in the clinic-based sample (all P < 0.001). We conclude that progression of motor scores in PD decreases with advancing disease in PD. However, disability continues to deteriorate with advancing disease and with the development of disease complications that are likely to be related to additional extrastriatal pathology.
authors.affiliation: Department of Clinical Neurosciences, Royal Free Hospital, University College London, London, United Kingdom. a.schrag@medsch.ucl.ac.uk
authors.forename: Anette
authors.initials: A
authors.lastname: Schrag
authors.forename: Richard
authors.initials: R
authors.lastname: Dodel
authors.forename: Annika
authors.initials: A
authors.lastname: Spottke
authors.forename: Bernhard
authors.initials: B
authors.lastname: Bornschein
authors.forename: Uwe
authors.initials: U
authors.lastname: Siebert
authors.forename: Niall P
authors.initials: NP
authors.lastname: Quinn
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003072:Cognition Disorders / Q000209:etiology; D003710:Demography; D004185:Disability Evaluation; D018450:Disease Progression; D005500:Follow-Up Studies; D006761:Hospitals; D006801:Humans; D008875:Middle Aged; D009069:Movement Disorders / Q000209:etiology; D009460:Neurologic Examination; D009483:Neuropsychological Tests; D010300:Parkinson Disease / Q000188:drug therapy / Q000453:epidemiology / Q000503:physiopathology*; D011446:Prospective Studies; D012111:Residence Characteristics