Working memory in Parkinson's disease patients: clinical features and response to levodopa

Abstract

-Objective: To evaluate the clinical features of the working memory (WM) in Parkinson's disease (PD) patients and to test the effect of levodopa on WM. Method: The paradigm was based on the 'n-back' tasks, which enables to study the level of executive demand (three levels of difficulty) and the domain of the information being processed (spatial items, faces and letters). The effect of levodopa was studied by testing PD patients in "on" and "off" states. Results: PD patients performed less well in WM tasks than controls. There was no interaction between groups and complexity. Levodopa therapy had a positive effect only on spatial WM tasks but no effect on complexity. Conclusion: Our results suggest that impairment observed may result from a maintenance deficit within WM regardless the level of processing and levodopa therapy presents a positive effect on spatial WM.Key WOrDs: Parkinson's disease, striatum, executive functions, working memory, levodopa. memória de trabalho em pacientes com doença de Parkinson: características clínicas e resposta a levodopaResumo -Objetivo: Avaliar as características clínicas da memória de trabalho (MT) em pacientes com doença de Parkinson (DP) e testar o efeito da levodopa na MT. Método: O paradigma baseou-se nas tarefas 'n-back', que permitem avaliar o nível de demanda executiva (três níveis de dificuldade) e o domínio da informação sendo processado (posições espaciais, faces e letras). O efeito da levodopa foi estudado pela testagem dos pacientes no estado "on" e "off". Resultados: Pacientes com DP apresentam desempenho inferior ao dos controles em tarefas de MT. Não foi observada interação entre grupos e complexidade. A terapia com levodopa mostrou efeito positivo sobre a modalidade espacial, e nenhum efeito sobre a complexidade. Conclusão: Nossos resultados sugerem que o comprometimento observado pode resultar de défict de manutenção da MT, independente do nível de processamento. A terapia com levodopa apresenta efeito positivo sobre a MT espacial.PALAvrAs-ChAve: doença de Parkinson, striatum, funções executivas, memória de trabalho, levodopa.Groupe hospitalier de la Pitié-salpêtrière,

Executive dysfunction and motor symptoms in Parkinson's disease

“…Our findings are also in agreement with these studies related by Starkstein and Merello 21 , which showed operational memory deficit in PD in tests which require correct coordination of two tasks simultaneously. The recent work of Beato et al 22 , identified that patients with PD presented inferior performance to the control group in working memory tasks and levodopa therapy presents a positive effect on spatial operational memory.…”

Theory of Cognitive Aging in Parkinson Disease

“…When compared to placebo and the cholinesterase inhibitor galantamine, data indicated that levodopa regulates the speed of processing of new information. In PD, deficits in visuospatial working memory [4,5] have been described in participants who underwent medication withdrawal. Specifically, people with PD showed reduced storage capacity and impaired ability to filter, or inhibit irrelevant stimuli.…”

“…In PD, deficits in visuospatial working memory [4,5] have been described in participants who underwent medication withdrawal. In addition there is evidence that normal working memory performance in PD is maintained by compensatory mechanisms.…”

“…Parkinson disease (PD) is an age-related neurodegenerative disorder that can result in a variety of cognitive deficits including impairments in processing speed [1][2][3], working memory [4,5] and inhibition [6,7]. In addition, elderly people with PD are at higher risk for loss of independence due to cognitive impairment [8].…”

Avaliação do Sistema Perceptual em Idosos Saudáveis e em Idosos com Doença de Parkinson

“…Funcionamento executivo compreende a inibição de respostas automáticas, recuperação da memória declarativa, planejamento, monitoramento, flexibilidade cognitiva e manutenção e manipulação da informação na memória de trabalho. Deste modo, a diminuição da velocidade psicomotora pode influenciar o funcionamento executivo na vida diária e o comprometimento motor, associado a manifestações psíquicas, remetem a incapacidades funcionais e perceptuais, responsáveis pelo decréscimo da qualidade de vida desses indivíduos 9,11,12 .…”