Clinical investigation of mild cognitive impairment in patients with Parkinson's disease

Abstract

Objective To describe the prevalence and neuropsychological character of mild cognitive impairment (MCI) associated with Parkinson' s disease(PD-MCI). Methods One hundred and three PD patients and a control group of 32 healthy old subjects were chosen. Psychometric assessment included the Mini Mental State Examination, the Dementia Rating Scale and a series of neuropsychol ogicaltests. The Hamilton Rating Scale of Depression was used to assess depression in PD patients. Results (1)Twenty-one (20.4%) PD patients was diagnosed with dementia, 45 (43.7%) had a MCI and only 37(35.9%) had no cognitive impairment; (2) Subjects with PD-MCI were older, had a later onset of the PD,and displayed more severe motor symptoms compared with those without cognitive impairment; (3) The prevalence and neuropsychological profile of PD-MCI were thought to correlate with the dominating side and subtype of Parkinsonian symptoms, for patients with left-sided dominant symptoms had a significantly higher chance of suffering MCI than those with right-sided dominant symptoms, the ratio being 74.2% vs 42.2%,χ<'2 =7. 589,P <0.05; The tremor-dominant group took less time than the mixed group for Stroop word test measurement ((80.8±39.9) s vs (94.4±30.0) s,t=3.332,P<0.01). Conclusion Identification of MCI is of important clinical significance, which helps to treat patients differently and thus predict the prognosis. Key words: Pakinson disease; Congnition disorders; Prevalence; Neuropsychological tests