Characteristics of executive function impairment in Parkinson’s disease patients without dementia

Abstract

Executive function impairments in Parkinson's disease (PD) are well documented. However, uncertainties remain regarding the impact of these deficits on other areas of cognitive functioning. The goal of this study was to provide a comprehensive assessment of cognitive characteristics in patients with PD without dementia and to assess how any such deficits affected other areas of cognitive functioning. Forty PD patients without dementia were compared to healthy controls using measures of attention and speed of processing and a comprehensive set of executive function tests including working memory, planning, and problem solving. Measures of memory/learning and visuospatial skills were also included to examine the relationship between aspects of executive function and other areas of cognition. Patients with PD showed deficits on measures of executive function, problem solving, and visuospatial skills. However, they were unimpaired on measures of planning, attention, and memory/learning. Deficits in problem solving were only evident for tasks with a high visuospatial content and were no longer significant when visuospatial skills were controlled for. While deficits in executive function and visuospatial skills were apparent for PD patients compared to controls, many aspects of cognition remained intact. These can provide a focus for cognitive intervention strategies that can be effective in delaying decline for PD patients.

The Role of Feedback in Decision Making

“…But, given that PDs are unable to provide accurate verbal reports of their cue-outcome knowledge, planning is www.intechopen.com based on knowledge that is not consciously accessible (Witt et al, 2006). In line with Witt el al's proposals, McKinlay et al (2010) presented PDs with a test battery including decision making and problem solving tasks designed to engage executive functions. PDs showed preserved goal directed behaviors, though the authors suggest that performance reflected conscious access to knowledge in their tasks.…”

“…Goal directed processes tend to be preserved in PDs, but incremental acquisition of cueoutcome knowledge which enables the quick execution of highly practiced knowledge (i.e. habits) is impaired (McKinlay et al, 2010;Redgrave et al, 2010;Shohamy et al, 2006). Redgrave et al (2010) propose that some of the impairments observed in decision making may reflect intact goal directed learning (e.g., rostromedial striatum) that cannot be expressed autonomically because of a dysfunctioning habit learning systems (e.g., midbrain).…”

“…In their task goal directed, Wilkinson and Jahanshahi (2007) showed that PD's learning involved acquisition of the probabilistic cue (stimulus) -outcome (response) associations, but expression of this knowledge through speed up of responses was impaired (Wilkinson & Jahanshahi, 2007). To bring these points to bear more specifically to PD performance in the decision making tasks, some have claimed that failure to exhibit incremental cue-outcome learning (as in the WPT, or in some cases the IGT) is the result of slower rates of learning (McKinlay et al, 2010;Redgrave et al, 2010;Rutledge et al, 2009). Indeed, the most consistent core cognitive deficits reported in PDs are speed of processing, along with visuo-spatial ability and some components of executive functioning (McKinlay et al, 2010).…”

“…To bring these points to bear more specifically to PD performance in the decision making tasks, some have claimed that failure to exhibit incremental cue-outcome learning (as in the WPT, or in some cases the IGT) is the result of slower rates of learning (McKinlay et al, 2010;Redgrave et al, 2010;Rutledge et al, 2009). Indeed, the most consistent core cognitive deficits reported in PDs are speed of processing, along with visuo-spatial ability and some components of executive functioning (McKinlay et al, 2010). McKinlay et al (2010) propose that deficits in general memory, planning, and attention are much more variable, and one reason for this could be as a result of the particular methodology used to study these processes.…”

Behavioural Assessment of the Dysexecutive Syndrome (BADS): Adaptação e Evidências de Validade

“…No entanto, alterações cognitivas são uma importante causa de incapacidade funcional nesses pacientes, com uma prevalência que pode chegar a 93%, podendo ser tão limitantes quanto os sinais motores (Sammer, Reuter, Hullmann, Kaps, & Vaitl, 2006;Campos-Sousa, Campos-Sousa, Ataíde Jr., Soares, & Almeida, 2010). Entre os prejuízos cognitivos mais comuns na DP estão as alterações das FEs, que podem estar presentes desde os primeiros estágios da doença (Mckinlay, Grace, Dalrymple-Alford, & Roger, 2010).…”