Using executive heterogeneity to explore the nature of working memory deficits in Parkinson's disease.

Full Abstract

Idiopathic Parkinson's disease (IPD) is characterised by a triad of motor symptoms, namely bradykinesia, rigidity and resting tremor, although cognitive impairment is a common feature of the disease and has been accepted as one of the strong predictors of quality of life in such patients. Neuropsychological testing in Parkinson's disease often reveals a pattern of cognitive impairment similar to that observed in patients with frontal lobe lesions, although clear differences between the two groups have also often been reported. This apparent inconsistency in the literature may reflect heterogeneity among different groups of patients with Parkinson's disease, although to date this possibility has not been formally addressed. In this study, two groups of patients with Parkinson's disease were assessed on a novel verbal memory task, which allowed different aspects of working memory function such as maintenance, retrieval and manipulation to be tested within the same general paradigm. The two groups were selected according to either good or bad performance on a 'standard', visuospatial test of executive function (The Tower of London Task), but were well matched on all other demographic and cognitive measures tested. The sub-group of Parkinson's disease patients with Tower of London defined executive deficit were specifically impaired at manipulating information within verbal working memory, both compared to controls and to the group of patients with no predefined executive impairments. In contrast, the three groups did not differ in their ability to maintain or retrieve information within verbal working memory. Given the known preferential role of the dorsolateral frontal cortex in higher executive functions, (including both planning and the manipulation of information within working memory), these results suggest that, in a subset of Parkinson's disease patients, it is the frontostriatal circuitry involving this region which is primarily affected, while other components of this circuitry may be relatively spared. The results also suggest that performance on the Tower of London task may prove to be a useful discriminant variable in defining the nature of cognitive heterogeneity in Parkinson's disease.

Learn Faster Today Improve your study skills

Author information

Author/s: Lewis, Simon J G (SJ); Cools, Roshan (R); Robbins, Trevor W (TW); Dove, Anja (A); Barker, Roger A (RA); Owen, Adrian M (AM);

Affiliation: Cambridge Centre for Brain Repair, Forvie Site, Addenbrooke's Hospital, University of Cambridge, CB2 2PY, UK. sigl2(-atsign-)wbic.cam.ac.uk

Journal and publication information

Publication Type: Comparative Study; Journal Article; Research Support, Non-U.S. Gov't

Journal: Neuropsychologia (Neuropsychologia), published in England. (Language: eng)

Reference: 2003-; vol 41 (issue 6) : pp 645-54

Dates: Created 2003/02/19; Completed 2003/05/15; Revised 2006/11/15;

PMID: 12591022, status: MEDLINE (last retrieval date: 11/6/2008)

Sourced from the National Library of Medicine. Abstract text and other information may be subject to copyright.

External Links for this article (including full text providers, if available):

Click Electronic Full-text Provider Links to see options for finding the electronic full text links to this article. Note there may be a subscription or fee required for access to the full text. See our FAQ for information on finding FREE full text articles.

This article may also be located in paper journal collections available in many libraries. Use the Journal and Publication Information above to find the full article.

MeSH headings (categories)

This article was linked to the MESH Headings shown below.

This article has not been indexed for related articles as yet, however you can still use the live related article search links below.

See 100+ related articles.