Assessment of cognitive impairment based on the clinical heterogeneity of idiopathic Parkinson＇s disease

Abstract

Objective To assess cognitive impairment of patients with idiopathic Parkinson＇s disease（PD）of different clinical subgroups. Methods The cluster analysis approach was used to classify PD patients on the basis of their clinical features, and then compare their cognitive function according their Montreal Cognitive Assessment （MoCA）score. Results One-hundred and six patients were divided into 5 groups by means of cluster analysis：A. young-onset（n = 35）, B. rapid disease progression（n = 6）; C. tremor dominant（n = 36）, D. haplo-non-tremor dominant（n =18）,E. non-tremor dominant with depression（n = 11）. The MoCA score and proportion of abnormal scores differed among the 5 groups significantly,especially between the subgroup E（19.00 ±5.47）and the subgroup A（23. 66 ± 3.51）（P 〈 0. 05）, the former was more seriously impaired in clock drawing task（1.73 ± 1. 01 vs.2. 66 ±0. 59 ,t = -2. 904,P =0. 013）, alertness（0. 55 ±0. 52 vs. 0. 91 ±0. 28 ,t = -2. 241 ,P =0. 045）,semantic fluency（0. 64 ±0. 51 vs. 0. 97 ±0. 17 ,t = -3. 429,P =0. 001）and orientation domains than the latter（4. 91 ± 1.38 vs. 5.80±0.47,t = -3.321,P =0.020）. Conclusions The cognitive impairment in PD patients are common as well as heterogeneous. Key words: Parkinson＇s disease; Cognitive impairment