Neuropsychological performance differences between two groups of probable-AD patients from different areas of Brazil (original) (raw)
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Differences between Early and Late-Onset Alzheimer’s Disease in Neuropsychological Tests
Frontiers in Neurology, 2012
Although patients with Alzheimer disease (AD) share clinical and histological features regardless of age of onset, the hypothesis that early onset AD constitutes a distinct subgroup prevails. Some authors suggest that early attention or language impairment constitute patterns of differentiation in terms of neuropsychological profile, between these groups. However, investigations are not consensual in terms of cognitive domains affected in each group. Aim: To investigate whether there is early neuropsychological difference between two types of AD using the conventional dividing line of 65 years. Methods: We evaluated the results obtained in the Mini-Mental State Examination (MMSE) and in a comprehensive neuropsychological battery-Battery of Lisbon for the Assessment of Dementia (BLAD), at a Dementia clinic in the University Hospital of Coimbra and a Memory Clinic. The study was developed in consecutive patients with a clinical probable diagnosis of mild to moderate AD, using standard criteria (DSMIV and NINCDS-ADRDA). Statistical analysis was performed using Qui-square and U-Mann-Whitney, for categorical and non-categorical variables. The degree of relation between variables, was measured using the coefficient of correlation r s de Spearman. Results: The total sample included 280 patients: 109 with early onset AD and 171 with a late-onset form. Groups were comparable in terms of gender, education or severity of disease, and MMSE. In BLAD, for univariate analysis the early onset group had lower scores in Naming (p = 0.025), Right-Left Orientation (p = 0.029) and Praxis (p = 0.001), and better performances in Orientation (p = 0.001) and Visual Memory (p = 0.022). After application of Bonferroni correction for multiple comparisons only Praxis and Orientation could differentiate the two groups. No significant differences were found in other tests or functions. Discussion: The results are suggestive of dissociated profiles between early and late-onset AD. Younger patients have a major impairment in Praxis and a tendency for a great impairment in neocortical temporal functions. AD patients with lateonset forms had a tendency for worse performances in Visual Memory and Orientation, suggesting a more localized disease to the limbic structures.
Preclinical prediction of AD using neuropsychological tests
Journal of the International Neuropsychological Society, 2001
Normals (N = 42) and patients with mild memory difficulty (N = 123) were given a neuropsychological test battery, and then followed annually for 3 years to determine which individuals developed sufficient functional change that they met clinical criteria for AD. Twenty-three of the 123 participants with mild memory difficulty converted to a diagnosis of probable Alzheimer's disease (AD) within 3 years of follow-up. Four of the 20 neuropsychological measures obtained at baseline, were useful in discriminating the groups on the basis of their status 3 years after the tests were given. The 4 discriminating tests pertained to assessments of memory and executive function. When the controls were compared to the individuals with memory impairments who ultimately developed AD (the converters), the accuracy of discrimination was 89%, based on the neuropsychological measures at baseline. The discrimination of the controls from the individuals with mild memory problems who did not progress...
Criteria for the diagnosis of Alzheimer’s disease
This consensus prepared by the Scientific Department of Cognitive Neurology and Aging of the Brazilian Academy of Neurology is aimed at recommending new criteria for the diagnosis of dementia and Alzheimer's disease (AD) in Brazil. A revision was performed of the proposals of clinical and of research criteria suggested by other institutions and international consensuses. The new proposal for the diagnosis of dementia does not necessarily require memory impairment if the cognitive or behavioral compromise affects at least two of the following domains: memory, executive function, speech, visual-spatial ability and change in personality. For the purpose of diagnosis, AD is divided into three phases: dementia, mild cognitive impairment and pre-clinical phase, where the latter only applies to clinical research. In the dementia picture, other initial forms were accepted which do not involve amnesia and require a neuroimaging examination. Cerebrospinal fluid biomarkers are recommended for study, but can be utilized as optional instruments, when deemed appropriate by the clinician.
Preclinical" AD revisited: Neuropathology of cognitively normal older adults
Neurology, 2000
To classify neuropathologic alterations in the brains of nondemented older adults using current sets of criteria for AD. Background: AD neuropathologic alterations are found in the brains of some nondemented elderly subjects and suggest the possibility of presymptomatic AD. Three sets of guidelines have been developed to classify AD using senile plaques, neuritic plaques, and neurofibrillary tangles (NFT). Methods: Neuropathologic changes in 59 older adults followed longitudinally with a standard battery of mental status measures were investigated using Khachaturian, Consortium to Establish a Registry for Alzheimer's Disease (CERAD), and National Institute on Aging-Reagan Institute (NIA-RI) guidelines. AD neuropathologic markers were evaluated in neocortical and allocortical regions. Cases were categorized as neuropathologically "normal" or "AD-like" and compared for possible mental status differences. Results: Between 11 and 49% of cases met one or more of the three classifications of AD. With adjustments for multiple comparisons, only NFT in hippocampal CA1 region were associated with autopsy age, suggesting that this may represent a pathologic process associated with normal brain aging. Using the NIA-RI guidelines, subjects in the AD-like group performed less well on the immediate paragraph recall and word-list delayed recall than their counterparts who did not meet these guidelines. Conclusions: These data indicate that the prevalence of "preclinical" AD in our population is relatively low based on the NIA-RI classification. Although many subjects had AD-like changes based on CERAD and Khachaturian guidelines, they exhibited no differences in mental performance, suggesting that the aging brain may be able to withstand such structural changes without meaningful impact on mental functioning.
Alzheimer's disease (AD) has traditionally been defi ned as a type of dementia, and criteria have been provided by the National Institute of Neurological and Communicative Disorders and Stroke -Alzheimer's Disease and Related Disorders Association (NINCDS-ADRDA) [1], the fourth edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-IV) , and the 10th revision of the International Classifi cation of Diseases (ICD-10) . Of these sets of criteria, the NINCDS-ADRDA criteria were most widely used in dementia research. Th ere were several notable aspects of these criteria: (a) patients had to have cognitive defi cits and functional compromise severe enough to meet criteria for dementia, (b) a confi rmed diagnosis depended on postmortem examination, (c) the most accurate diagnosis that the clinician could make for the living patient was 'probable AD' , (d) other possible causes of cognitive impairment had to be excluded by the clinician, and (e) the cognitive defi cits were not oper ationa lized for characteristics or severity. When applied by expert clinicians, these criteria have an 80% positive predictive value and a 60% negative predictive value for the accurate clinical diagnosis of AD when compared with postmortem examination .