Misplaced objects test: estudos exploratórios num grupo de adultos idosos com défice cognitivo ligeiro

Abstract

Neste estudo, são apresentados os resultados de uma investigação exploratória com o MOT em idosos com diagnóstico clínico de Défice Cognitivo Ligeiro (DCL) e informação adicional respeitante à validade e utilidade clínica do teste. A amostra consiste em 40 doentes idosos, observados no Serviço de Psiquiatria dos Hospitais da Universidade de Coimbra. Foram definidos dois grupos: (i) Funcionamente Cognitivo Preservado (grupo de controlo) (n = 20), (ii) Défice Cognitivo Ligeiro (n = 20). As funções cognitivas e o estado emocional foram avaliados. Um outro grupo foi utilizado como critério de comparação (iii) estudantes universitários (n = 45). O grupo com DCL demonstra desempenhos significativamente inferiores aos do grupo de controlo. Observaram-se correlações positivas significativas entre os desempenhos no MOT e no desempenho no teste Pares de Palavras (grupo de controlo), nomeadamente com a tarefa de evocação imediata (r=.757; p <0.01), evocação diferida (r=.767; p <0.01) e reconhecimento (r=.537; p<0.05). As pontuações no MOT demonstram estar associadas de forma significativa com os resultados do Mini-Mental State Examination (controlo - total: r=.748; p<0.01/DCL – ensaio 1: r=.553; p<0.05). Os resultados no MOT discriminam os grupos de DCL e Controlo e estão associados a procedimentos de aprendizagem verbal, mais especificamente, de aprendizagem de pares associados (associações positivas significativas entre o teste Pares de Palavras e o MOT, no grupo de controlo). Associações significativas e positivas entre o MOT e o MMSE (grupo de controlo e grupo com DCL), sugerem que o MOT é igualmente sensível aos processos de declínio cognitivo (avaliados pelo MMSE). O MOT sofre efeito de tecto no grupo de estudantes universitários

In the clinical context, patients often report a set of symptoms that can be broadly defined as "forgetfulness in daily activities". Given a patient with these symptoms, the fundamental question that arises is whether they are the manifestation of an ongoing neuropathological process or are a nonstructural dysfunction associated with neurocognitive processes. The role of neuropsychological assessment assumes particular relevance in pathophysiological clarification and assignment of a prognostic value to forgetfulness in daily activities. However, there remains some controversy in the methods usually employed to achieve these objectives, such as the generalization of results, which is made without their ecological validity has been consistently reflected in studies. Crook, Ferris and McCarthy (1979) developed the Misplaced Objects Test (MOT). MOT is a computerized test of object location recall and also a measure of everyday visual memory with good ecological validity. In this study, we provide the results of an exploratory research with the Misplaced Object Test in elderly adults with clinical diagnosis of Mild Cognitive Impairment (MCI) and additional information concerning the validity and clinical utility of the test. Study participants were 40 geriatric patients, recruited in the Psychiatric Department of Coimbra University Hospitals. Two groups were defined: (i) Unimpaired Cognitive Functioning (control group; n=20), (ii) Mild Cognitive Impairment (n=20). Cognitive function and emotional status were also assessed. Another group was used as a comparison: (iii) University Students (n=45). The group with MCI performed significantly lower than the control group. There were significant positive correlations between performance in the MOT and performance in Paired Associate Learning Test (control group), particularly with the task of immediate recall (r =. 757, p <0.01), delayed recall (r =. 767, p <0.01) and recognition (r =. 537, p <0.05). The results in the MOT shown to be associated significantly with the results of Mini-Mental State Examination (control - total: r=.748; p<0.01/MCI – trial 1: r=.553; p<0.05). MOT results show discrimination ability between Control and MCI groups and is most closely associated with a verbal learning procedure, more specifically, Paired Associate Learning (high positive relationships between Paired Associate Learning Test and the MOT, in the control group). A significant positive association between MOT and MMSE scores (control and MCI groups), suggests that MOT is also sensitive to processes of cognitive decline (assessed by MMSE). MOT suffers from ceiling effect in the group of university students