Memory for gist and detail information in patients with Parkinson's disease

Objective: Memory formation is proposed to be a dual process that involves the simultaneous memorisation of both detailed information (item-specific memory) and gist information (gist memory). Memory deficits have been reported in patients with Parkinson's disease (PD); however, few studies have explicitly addressed the nature of these deficits. To obtain a detailed understanding of memory dysfunction in patients with PD, it is of crucial importance to establish whether item-specific memory and gist memory performance are impaired. The aim of this study is to explore whether gist memory and item-specific memory performance are still intact in patients with PD, as well as to determine which psychological mechanisms are responsible for memory formation. Setting: Two hospitals in northern Taiwan. Participants: Thirty-nine patients with PD and 28 normal controls were recruited. Each participant received a gist-based recognition test following the Deese-Roediger-McDermott paradigm, as well as neuropsychological tests and measures of clinical characteristics. Results: Gist memory was impaired in patients with advanced-stage disease (Hoehn and Yahr (H&Y) stage: III) (F-2,F-64= 3.58, p= 0.033), whereas item-specific memory was preserved throughout all disease stages. Correlation analysis showed that item-specific memory was related to executive functions in normal controls and early-stage patients with PD (H&Y stage: III); however, item-specific memory was related to episodic memory, rather than to executive functions, in advanced-stage patients with PD. Moreover, gist memory was related to episodic memory, but only in early-stage patients with PD. Conclusions: We discovered that impaired gist memory is found in advanced-stage, but not in early-stage, patients with PD. Our findings suggest that the techniques used to take advantage of the relatively preserved gist memory in early-stage patients with PD, as well as the preserved item-specific memory in patients with PD of all stages, could be useful for memory rehabilitation programmes

Advanced Theory of Mind in patients at early stage of Parkinson's disease

Advanced Theory of Mind (TOM) refers to the sophisticated ability to infer other people's thoughts, intentions, or emotions in social situations. With appropriate advanced ToM, one can behave well in social interactions and can understand the intention of others' behavior. Prefrontal cortex plays a vital role in this ability, as shown in functional brain imaging and lesion studies. Considering the primary neuropathology of Parkinson's disease (PD) involving the frontal lobe system, patients with PD are expected to exhibit deficits in advanced ToM. However, few studies on this issue have been explored, and whether advanced ToM is independent of executive functions remains uncertain. Thirty-nine early non-demented PD patients and 40 normal control subjects were included. Both groups were matched in age, level of education, and verbal intelligence quotient. Each participant received advanced ToM, executive functions, and verbal intelligence quotient tests. We discovered that the performance of the PD patients on the Cartoon ToM task was significantly poorer than that of their normal counterparts. Correlation analysis revealed that performance scores of advanced ToM in PD patients were significantly associated with their executive functions scores; however, this is not the case for normal controls. We conclude that dysfunction of advanced TOM develops in early PD patients, who require more cognitive abilities than their normal counterparts to generate advanced ToM. Our findings might be helpful in developing educational and medical care programs for PD patients in the future. (C) 2011 Elsevier Ltd. All rights reserved

More than an "inverted-U"? An exploratory study of the association between the catechol-o-methyltransferase gene polymorphism and executive functions in Parkinson's disease.

Executive dysfunction is common in Parkinson's disease (PD) patients. The catechol-O-methyltransferase (COMT) Val158Met polymorphism has been proposed to affect executive functions (EFs) in the prefrontal cortex. The present study attempted to explore the influence of the COMT polymorphism on EFs in patients with PD. Fifty-four PD patients were recruited and underwent neuropsychological assessments for three core EFs. The COMT polymorphism was genotyped using the TaqMan SNP Genotyping Assay. Participants were divided into three study groups: Val homozygotes, heterozygotes, and Met homozygotes. The three COMT genotype groups had significantly different performances in set-shifting [χ2 (2, 54) = 9.717, p = 0.008] and working memory tasks [χ2 (2, 54) = 7.806, p = 0.020]. Post-hoc analyses revealed that PD Val homozygotes performed significantly poorer in the set-shifting task than did either the PD Met homozygotes (z = -2.628, p = 0.009) or PD heterozygotes (z = -2.212, p = 0.027). Our explorative results suggest that the putative level of prefrontal dopamine influenced set-shifting through a "cane-shaped" dopamine level-response relationship. Our results have clinical implications, which may influence PD treatment with dopamine in the future because the optimal dopamine level to maximize EFs may vary based on the clinical course and COMT polymorphism status. Further study recruiting a larger number of participants is needed to confirm our preliminary findings

Probing Folate-Responsive and Stage-Sensitive Metabolomics and Transcriptional Co-Expression Network Markers to Predict Prognosis of Non-Small Cell Lung Cancer Patients

Tumour metabolomics and transcriptomics co-expression network as related to biological folate alteration and cancer malignancy remains unexplored in human non-small cell lung cancers (NSCLC). To probe the diagnostic biomarkers, tumour and pair lung tissue samples (n = 56) from 97 NSCLC patients were profiled for ultra-performance liquid chromatography tandem mass spectrometry (UPLC/MS/MS)-analysed metabolomics, targeted transcriptionomics, and clinical folate traits. Weighted Gene Co-expression Network Analysis (WGCNA) was performed. Tumour lactate was identified as the top VIP marker to predict advance NSCLC (AUC = 0.765, Sig = 0.017, CI 0.58–0.95). Low folate (LF)-tumours vs. adjacent lungs displayed higher glycolytic index of lactate and glutamine-associated amino acids in enriched biological pathways of amino sugar and glutathione metabolism specific to advance NSCLCs. WGCNA classified the green module for hub serine-navigated glutamine metabolites inversely associated with tumour and RBC folate, which module metabolites co-expressed with a predominant up-regulation of LF-responsive metabolic genes in glucose transport (GLUT1), de no serine synthesis (PHGDH, PSPH, and PSAT1), folate cycle (SHMT1/2 and PCFR), and down-regulation in glutaminolysis (SLC1A5, SLC7A5, GLS, and GLUD1). The LF-responsive WGCNA markers predicted poor survival rates in lung cancer patients, which could aid in optimizing folate intervention for better prognosis of NSCLCs susceptible to folate malnutrition