The relationships between mild cognitive impairment and phenotype in Parkinson's disease

Jennifer Y Y Szeto, Claire O'Callaghan, James M. Shine, Courtney C. Walton, Loren Mowszowski, Sharon L. Naismith, Glenda M. Halliday, Simon J G Lewis*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

20 Citations (Scopus)
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BACKGROUND: The concept of differing clinical phenotypes within Parkinson's disease (PD) is well represented in the literature. However, there is no consensus as to whether any particular disease phenotype is associated with an increased risk of mild cognitive impairment (MCI) using the newly proposed Movement Disorders Society diagnostic criteria for this feature. AIMS: To explore the expression of PD-MCI in relation to the heterogeneity of idiopathic PD. METHODS: A cluster analysis incorporating a range of specific demographic, clinical and cognitive variables was performed on 209 patients in the early stages of PD (between Hoehn and Yahr stages I-III). Post hoc analyses exploring variables not included in the clustering solution were performed to interrogate the veracity of the subgroups generated. RESULTS: This study identified four distinct PD cohorts: a younger disease-onset subgroup, a tremor dominant subgroup, a nontremor dominant subgroup, and a subgroup with rapid disease progression. The present study identified a differential expression of PD-MCI across these subgroups, with the highest frequency observed in the non-tremor dominant cluster. The non-tremor dominant subgroup was also associated with a higher prevalence of freezing of gait, hallucinations, daytime somnolence, and rapid eye movement sleep behavior disorder compared with other subgroups. CONCLUSIONS: This study confirms the existence of heterogeneity within the early clinical stages of PD and for the first time highlights the differential expression of PD-MCI using the newly defined diagnostic criteria for this feature. An improved understanding of PD-MCI and its clinical relationships may lead to an improved understanding of the pathophysiology underlying heterogeneity in PD.

Original languageEnglish
Article number15015
Pages (from-to)1-7
Number of pages7
JournalParkinson's Disease
Publication statusPublished - 27 Aug 2015
Externally publishedYes

Bibliographical note

Copyright Parkinson's Disease Foundation/Macmillan Publishers Limited 2015. Version archived for private and non-commercial use with the permission of the author/s and according to publisher conditions. For further rights please contact the publisher.


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