Lexical semantic memory in amnestic mild cognitive impairment and mild Alzheimer's disease

Abstract

-Objective: To study lexical semantic memory in patients with amnestic mild cognitive impairment (aMCI), mild Alzheimer's disease (AD) and normal controls. Method: Fifteen mild AD, 15 aMCI, and 15 normal control subjects were included. Diagnosis of AD was based on DSM-IV and NINCDS-ADRDA criteria, and that of aMCI, on the criteria of the International Working Group on Mild Cognitive Impairment, using CDR 0.5 for aMCI and CDR 1 for mild AD. All subjects underwent semantic memory tests (Boston Naming-BNT, CAMCOG Similarities item), Rey Auditory Verbal Learning Test (RAVLT), Mini-Mental Status Examination (MMSE), neuropsychological tests (counterproofs), and Cornell Scale for Depression in Dementia. Data analysis used Mann-Whitney test for intergroup comparisons and Pearson's coefficient for correlations between memory tests and counterproofs (statistical significance level was p<0.05). Results: aMCI patients were similar to controls on BNT and Similarities, but worse on MMSE and RAVLT. Mild AD patients scored significantly worse than aMCI and controls on all tests. Conclusion: aMCI impairs episodic memory but tends to spare lexical semantic system, which can be affected in the early phase of AD.KEy WORDS: semantic memory, mild cognitive impairment, Alzheimer's disease, neuropsychological tests.Memória léxico-semântica no comprometimento cognitivo leve amnéstico e doença de Alzheimer leve RESUMO -Objetivo: Estudar a memória léxico-semântica no comprometimento cognitivo leve amnésti-co (aCCL), doença de Alzheimer (DA) leve e controles normais. Método: Incluímos 15 pacientes com DA leve, 15 com aCCL e 15 controles normais, usando os critérios DSM-IV, NINCDS-ADRDA e CDR 1 para DA, e os do International Working Group on Mild Cognitive Impairment, e CDR 0,5 para aCCL. Todos os sujeitos passaram por testes de memória semântica (Teste de nomeação de Boston -TNB, item de Similaridades do CAMCOG), teste de aprendizado auditivo-verbal de Rey (TAAVR), Mini-Exame do Estado Mental (MEEM), testes neuropsicológicos (contraprovas) e Escala Cornell para Depressão em Demência. A análise dos dados usou o teste de Mann-Whitney para comparações entre os grupos e o coeficiente de Pearson para correlação entre testes e contraprovas (nível de significância p<0,05). Resultados: Os pacientes com aCCL foram semelhantes aos controles no TNB e Similaridades, mas inferiores no MEEM e TAAVR. Pacientes com DA leve tiveram performance inferior à de sujeitos com aCCL e controles em todos os testes. Conclusão: O aCCL prejudica a memória episódica, mas tende a poupar o sistema léxico-semântico, que pode estar afetado na fase inicial da DA. PALAVRAS-ChAVE: memória semântica, comprometimento cognitivo leve, doença de Alzheimer, testes neuropsicológicos.

Memory for Names Test Provides a Useful Confrontational Naming Task for Aging and Continuum of Dementia

“…Many studies have demonstrated the utility of the BNT in distinguishing between late stage AD and age-related decline [5-7]. More recent studies of the BNT in the context of normal aging, MCI, and AD populations have repeatedly shown MCI patients performing normally or similar to age-matched controls on the BNT [8, 9]. These data suggest that while the BNT has utility in normal aging and distinguishing normal aging from AD, it has less utility in identifying MCI.…”

Diagnostic Value of Time-Constrained Naming Test in Mild Cognitive Impairment

“…Elderly individuals with MCI show poor performance on semantically demanding tasks [26,29,31]. The relationship between the performance on semantically demanding tasks and the naming accuracy rate suggests semantic deficits in MCI.…”

“…The relationship between the performance on semantically demanding tasks and the naming accuracy rate suggests semantic deficits in MCI. First, poor semantic ability, as assessed by semantic categorization, was significantly associated with the accuracy rate in the BNT in patients with MCI [26]. Second, individuals with MCI performed more poorly on semantic verbal fluency tests than on phonemic verbal fluency tests [29,31].…”

“…Recent reviews have yielded evidence supporting the existence of noun naming deficits in individuals with MCI [10,14]. However, individual studies have revealed contradictory results: while some studies suggest that individuals with MCI performed significantly more poorly on the BNT than HE subjects [4,5,6,7,8,9,11,12,13], other studies did not find significant differences between the two groups [10,25,26,27,28,29,30,31,32]. These inconsistent reports about the performance on BNT in MCI can be explained by differences in the diagnostic criteria, procedural differences in the naming tasks, and the possibility that only a segment of patients with MCI has naming deficits [33].…”

Validade discriminante do Teste de Aprendizagem Auditivo-Verbal de Rey: comparação entre idosos normais e idosos na fase inicial da doença de Alzheimer

“…O Teste de Aprendizagem Auditivo-Verbal de Rey (RAVLT) tem se mostrado útil na avaliação da memória de idosos [1][2][3][4] , contribuindo particularmente para o diagnóstico diferencial entre o envelhecimento normal e quadros demenciais como a demência do tipo Alzheimer [5][6][7] . O teste é utilizado para avaliação da memória e aprendizagem 8 , sendo considerado um instrumento sensível ao déficit de memória episódica 2,5,9 .…”