Objective: Parkinsonian signs, especially gait impairment, are common and associated with morbidity and mortality in older persons. Our objective was to test the hypothesis that substantia nigra neurofibrillary tangle...Objective: Parkinsonian signs, especially gait impairment, are common and associated with morbidity and mortality in older persons. Our objective was to test the hypothesis that substantia nigra neurofibrillary tangles (NFTs) are related to parkinsonian signs in older persons with and without dementia. Methods: We studied 86 deceased older Catholic clergy without idiopathic Parkinson’s disease from the Religious Order Study, a longitudinal clinical-pathological study. Mean age at death was 85.3 years. Signs of gait disturbance, bradykinesia, rigidity, and tremor were assessed proximate to death using a modified Unified Parkinson’s Disease Rating Scale. Forty-micrometer paraffin-embedded sections of substantia nigra were bleached before tau immunohistochemistry and the optical disector was used to count NFTs. We used multivariable linear regression to examine parkinsonian signs as a function of nigra NFTs, controlling for age, sex, education, and cortical NFTs. Results: Substantia nigra NFTs were present in 67 of 86 persons (77.9% ). After controlling for age, sex, education, and cortical NFTs, nigra NFTs were related to gait impairment (p < 0.001), but not bradykinesia, rigidity, or tremor. Results were not confounded by dementia, Braak score, neuroleptic medication, cerebral infarcts, or Lewy bodies. Interpretation: NFTs in the substantia nigra are associated with gait impairment in older persons with and without dementia.展开更多
Brains of 41 residents without neurodegenerative diseases in the high-incid ence area of ALS/parkinsonism-dementia complex (ALS/PDC) of the Kii Peninsula of Japan were neuropathologically examined. Neurofibrillary tan...Brains of 41 residents without neurodegenerative diseases in the high-incid ence area of ALS/parkinsonism-dementia complex (ALS/PDC) of the Kii Peninsula of Japan were neuropathologically examined. Neurofibrillary tangles (NFTs) in th e hippocampal area were present in 11 of the 41 cases, but the frequency of NFT -positive cases in each age group was similar to that of the normal Japanese p opulation and far less than that of Guamanians without ALS/PDC.展开更多
Explicit memory failure is the defining cognitive feature of Alzheimer’s disease and relates to the hallmark neuropathological features (plaques and tangles) of this illness. However, a pattern of preserved and impai...Explicit memory failure is the defining cognitive feature of Alzheimer’s disease and relates to the hallmark neuropathological features (plaques and tangles) of this illness. However, a pattern of preserved and impaired implicit memory has been found in Alzheimer’s disease patients that may be explained by the association between the processing demands of certain implicit tests and the level of regional Alzheimer’s disease neuropathology. In this study, we tested the hypothesis that these neuropathological features are related to implicit memory -measured by repetition priming -in a test that emphasized conceptual (or meaning-based) cognitive processing, and that the pathological changes are not related to implicit memory in a repetition priming test that emphasized perceptual (or sensory-based)-cognitive processing. Subjects were older nuns, priests and brothers participating in the Religious Orders Study who agreed to annual neurological and neuropsychological evaluation for Alzheimer’s disease and common neurological conditions of ageing, and brain autopsy at time of death. Explicit memory was measured by seven tests of episodic recall and recognition and converted to a previously established summary measure. Implicit memory was measured by four repetition priming tests. One test, category exemplar priming, emphasized conceptual, or meaning-based cognitive processing. A second test, word-identification priming, emphasized perceptual, or sensory-based cognitive processing. Two additional priming tests, picture-naming and word-stem completion, invoke both conceptual and perceptual processes. Neuritic and diffuse plaques, and neurofibrillary tangles identified by Bielschowsky silver stain, were quantified from five regions separately (frontal, parietal, temporal, entorhinal cortex and the hippocampus) and converted to a previously established summary measure. In linear regression analyses -controlling for age, sex and education-higher levels of Alzheimer’s disease neuropathology were related to lower levels of explicit memory proximate to death. Higher levels of neuropathology were also related to lower levels of priming on the category-exemplar test, but were not related to levels of priming on the word-identification, picturenaming, or word-stem completion tests. The results suggest that hallmark indices of Alzheimer’s disease neuropathology are associated with performance on priming tests to the extent that conceptual, but not perceptual, processing resources are required.展开更多
文摘Objective: Parkinsonian signs, especially gait impairment, are common and associated with morbidity and mortality in older persons. Our objective was to test the hypothesis that substantia nigra neurofibrillary tangles (NFTs) are related to parkinsonian signs in older persons with and without dementia. Methods: We studied 86 deceased older Catholic clergy without idiopathic Parkinson’s disease from the Religious Order Study, a longitudinal clinical-pathological study. Mean age at death was 85.3 years. Signs of gait disturbance, bradykinesia, rigidity, and tremor were assessed proximate to death using a modified Unified Parkinson’s Disease Rating Scale. Forty-micrometer paraffin-embedded sections of substantia nigra were bleached before tau immunohistochemistry and the optical disector was used to count NFTs. We used multivariable linear regression to examine parkinsonian signs as a function of nigra NFTs, controlling for age, sex, education, and cortical NFTs. Results: Substantia nigra NFTs were present in 67 of 86 persons (77.9% ). After controlling for age, sex, education, and cortical NFTs, nigra NFTs were related to gait impairment (p < 0.001), but not bradykinesia, rigidity, or tremor. Results were not confounded by dementia, Braak score, neuroleptic medication, cerebral infarcts, or Lewy bodies. Interpretation: NFTs in the substantia nigra are associated with gait impairment in older persons with and without dementia.
文摘Brains of 41 residents without neurodegenerative diseases in the high-incid ence area of ALS/parkinsonism-dementia complex (ALS/PDC) of the Kii Peninsula of Japan were neuropathologically examined. Neurofibrillary tangles (NFTs) in th e hippocampal area were present in 11 of the 41 cases, but the frequency of NFT -positive cases in each age group was similar to that of the normal Japanese p opulation and far less than that of Guamanians without ALS/PDC.
文摘Explicit memory failure is the defining cognitive feature of Alzheimer’s disease and relates to the hallmark neuropathological features (plaques and tangles) of this illness. However, a pattern of preserved and impaired implicit memory has been found in Alzheimer’s disease patients that may be explained by the association between the processing demands of certain implicit tests and the level of regional Alzheimer’s disease neuropathology. In this study, we tested the hypothesis that these neuropathological features are related to implicit memory -measured by repetition priming -in a test that emphasized conceptual (or meaning-based) cognitive processing, and that the pathological changes are not related to implicit memory in a repetition priming test that emphasized perceptual (or sensory-based)-cognitive processing. Subjects were older nuns, priests and brothers participating in the Religious Orders Study who agreed to annual neurological and neuropsychological evaluation for Alzheimer’s disease and common neurological conditions of ageing, and brain autopsy at time of death. Explicit memory was measured by seven tests of episodic recall and recognition and converted to a previously established summary measure. Implicit memory was measured by four repetition priming tests. One test, category exemplar priming, emphasized conceptual, or meaning-based cognitive processing. A second test, word-identification priming, emphasized perceptual, or sensory-based cognitive processing. Two additional priming tests, picture-naming and word-stem completion, invoke both conceptual and perceptual processes. Neuritic and diffuse plaques, and neurofibrillary tangles identified by Bielschowsky silver stain, were quantified from five regions separately (frontal, parietal, temporal, entorhinal cortex and the hippocampus) and converted to a previously established summary measure. In linear regression analyses -controlling for age, sex and education-higher levels of Alzheimer’s disease neuropathology were related to lower levels of explicit memory proximate to death. Higher levels of neuropathology were also related to lower levels of priming on the category-exemplar test, but were not related to levels of priming on the word-identification, picturenaming, or word-stem completion tests. The results suggest that hallmark indices of Alzheimer’s disease neuropathology are associated with performance on priming tests to the extent that conceptual, but not perceptual, processing resources are required.
