Clinical heterogeneity in newly diagnosed Parkinson’s disease
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To determine clinical heterogeneity in newly diagnosed Parkinson’s disease using cluster analysis and to describe the subgroups in terms of impairment, disability, perceived quality of life, and use of dopaminergic therapy.
We conducted a k-means cluster analysis in a prospective hospital based cohort of 133 patients with newly diagnosed Parkinson’s disease. Variables selected for the cluster analysis were age of disease onset, age at the moment of examination, rate of disease progression, levodopa responsive PD symptoms and levodopa non-responsive PD symptoms, cognition (mini-mental state examination) and emotional functioning (hospital anxiety depression scale). In addition, the homogeneous subgroups identified were clinically validated using descriptive statistics.
Cluster analysis with a two-cluster solution identified a younger and older age group. The three-cluster solution identified an intermediate group with respect to age. In both cluster solutions the older the onset group, the higher the progression rate and the level of motor impairments. The intermediate older onset group in the three cluster solution was characterized by more anxiety and depressive symptoms. Increasing age at disease onset was significantly associated with higher Hoehn and Yahr stages, level of disability and lower perceived quality of life.
We hypothesize there are three distinct subgroups in patients with newly diagnosed PD: a younger onset group, an intermediate older onset group with more anxiety and depressive symptoms and an oldest onset group with more motor impairment and higher rate of progression.
Key wordsParkinson’s disease heterogeneity cluster analysis
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- 1.Aaronson NK, Muller M, Cohen PD, Essink-Bot ML, Fekkes M, Sanderman R, Sprangers MA, te VA, Verrips E (1998) Translation, validation, and norming of the Dutch language version of the SF-36 Health Survey in community and chronic disease populations. J Clin Epidemiol 51:1055–1068PubMedCrossRefGoogle Scholar
- 9.Fahn S, Elton RL, Members of the UPDRS Development Committee (1987) Unified Parkinson’s Disease Rating Scale. In: Fahn S, Marsden CD, Calne DB (eds) Recent developments in Parkinson’s disease. Macmillan Healthcare Information, Florham Park, NJ, pp 153, 163, 293, 304Google Scholar
- 12.Goetz Cc (2006) New MDS-UPDRS working document. Presented at the first International World Parkinson’s disease Congress WashingtonGoogle Scholar
- 26.Suchowersky O, Reich S, Perlmutter J, Zesiewicz T, Gronseth G, Weiner WJ (2006) Practice Parameter: diagnosis and prognosis of new onset Parkinson disease (an evidence-based review): report of the Quality Standards Subcommittee of the American Academy of Neurology. Neurology 66:968–975PubMedCrossRefGoogle Scholar