| 1. |
- Jacobson, JM, et al.
(författare)
-
Multiple rapid automatic naming measures of cognition: Normal performance and effects of aging
- 2004
-
Ingår i: Perceptual and Motor Skills. - 0031-5125 .- 1558-688X. ; 98:3, s. 739-753
-
Tidskriftsartikel (refereegranskat)abstract
- Rapid automatic naming tasks are clinical tools for probing brain functions that underlie normal cognition. To compare performance for various stimuli in normal subjects and assess the effect of aging, we administered six single-dimension stimuli (color, form, number, letter, animal, and object) and five dual-dimension stimuli (color-form, color-number, color-letter, color-animal, and color-object) to 144 normal volunteers who ranged in age from 15 to 85 years. Rapid automatic naming times for letters and numbers were significantly less than for forms, animals, and objects. Rapid automatic naming times for color-number and color-letter stimuli were significantly less than for color-form, color-animal, or color-object stimuli. Age correlated significantly with rapid automatic naming time for each single-dimension stimulus and for color-form, color-number, color-animal, and color-object stimuli. Linear regression showed that rapid automatic naming times increased with age for aggregated color stimuli, aggregated single-dimension stimuli, and aggregated dual-dimension stimuli. This age effect persisted in subgroups less than 60 years of age and greater than 60 years of age. We conclude that normal performance time is dependent on the task, with letter and number stimuli eliciting most rapid responses, and that most rapid automatic naming times increase with age.
|
|
| 2. |
- Nielsen, NP, et al.
(författare)
-
Clinical utility of color-form naming in Alzheimer's disease: Preliminary evidence
- 2004
-
Ingår i: Perceptual and Motor Skills. - 0031-5125 .- 1558-688X. ; 99:3, s. 1201-1204
-
Tidskriftsartikel (refereegranskat)abstract
- Performances on Alzheimer's Quick Test color-form naming and Mini-Mental State Examination were compared for 38 adults with Alzheimer's disease and 38 age- and sex-matched normal controls. Group means differed significantly and indicated longer naming times by adults with Alzheimer's disease. The specificity for AQT color-form naming was 97% and sensitivity 97%, i.e., 3% false negatives. The specificity for Mini-Mental State Examination was 100% and sensitivity 84%, i.e., 16% false negatives. These findings, while supporting AQT color-form naming as a screening test for reductions in cognitive speed associated with Alzheimer's disease, are preliminary given the relatively small sample.
|
|
| 3. |
- Sun, Yongxin, et al.
(författare)
-
Inflammatory markers in matched plasma and cerebrospinal fluid from patients with Alzheimer's disease.
- 2003
-
Ingår i: Dementia and Geriatric Cognitive Disorders. - : S. Karger AG. - 1420-8008 .- 1421-9824. ; 16:3, s. 136-144
-
Tidskriftsartikel (refereegranskat)abstract
- It has been suggested that a number of molecules associated with inflammation are involved in the pathogenesis of Alzheimer's disease (AD). We measured the levels of alpha1-antichymotrypsin (ACT), alpha1-antitrypsin (AAT), interleukin-6 (IL-6), monocyte chemoattractant protein-1 (MCP-1) and oxidised low-density lipoprotein (oxLDL) in matched cerebrospinal fluid (CSF) and plasma of 141 patients with probable AD. We found a significant relationship between CSF and plasma levels of ACT (r = 0.4, p < 0.001), IL-6 (r = 0.74, p < 0.001), MCP-1 (r = 0.71, p < 0.001), and a borderline relationship between CSF and plasma oxLDL (r = 0.22, p < 0.05). In addition, linear regression analysis revealed a positive correlation between levels of CSF-ACT and oxLDL (p < 0.001), but an inverse relation between levels of CSF ACT, CSF AAT and MCP-1 (p < 0.001). A significant correlation was also found between levels of CSF ACT, oxLDL and the ratio of CSF to serum albumin, which is used as a measure of the blood-brain barrier function. Our data extend previous reports regarding the inflammatory markers in the plasma and CSF of patients with AD and provide good evidence that levels of ACT, IL-6, MCP-1 and oxLDL in plasma and CSF might be candidates as biomarkers for monitoring the inflammatory process in AD.
|
|
| 4. |
- Warkentin, Siegbert, et al.
(författare)
-
Regional Cerebral Blood Flow in Alzheimer's Disease: Classification and Analysis of Heterogeneity.
- 2004
-
Ingår i: Dementia and Geriatric Cognitive Disorders. - : S. Karger AG. - 1420-8008 .- 1421-9824. ; 17:3, s. 207-214
-
Tidskriftsartikel (refereegranskat)abstract
- Neural networks have been successfully applied to brain perfusion images to classify patients with Alzheimer’s disease from normal or other patient populations. Given the recognition that Alzheimer’s disease constitutes a heterogeneous disorder, the identification of subgroups sharing common functional brain deficits would constitute a further improvement in the utility of such methods. Therefore, we aimed to investigate whether neural networks could discriminate cortical perfusion deficits of patients with Alzheimer’s disease from normal brain perfusion. A second step was to identify subgroups of patients sharing similar perfusion deficits. The study population consisted of one group of 92 normal healthy subjects and one group of 132 patients with mild-to-moderate Alzheimer’s disease. The patients were diagnosed according to established criteria (DSM-IV and NINCDS-ADRDA). Regional cerebral blood flow was assessed by the non-invasive <sup>133</sup>Xe inhalation method, using a 64-detector system for measurements of blood flow in superficial cortical areas. The regional blood flow values were used as the only input to artificial neural networks with multilayer Perceptron architecture. The networks were trained using the back-propagation updating algorithm. A fourfold cross validation procedure was used in order to obtain the most reliable performance of the networks. The performance of the neural network, measured as the area under the receiver-operating characteristic curve, was 0.94, with a sensitivity for Alzheimer’s disease of 86% at a specificity of 90%. An analysis of the relative importance of cortical areas in the discrimination showed that left parietal areas were more important than the right homologous ones. A clustering analysis of the Alzheimer patients identified three or four subgroups of patients with clearly different combinations of blood flow pathology. A consistent finding in all subgroups was a significant deficit in temporoparietal blood flow of both hemispheres. Distinct group differences were seen in frontal, central and occipital areas with different combinations of involvement. This is the first study in which neural networks have been applied to brain perfusion images obtained with the <sup>133</sup>Xe inhalation method. The results demonstrate that a classification of patients with Alzheimer’s disease obtained with this method is compatible with the best results obtained with other brain imaging methods. The identification of clearly distinguishable patterns of blood flow pathology in subgroups of patients lends further support to the notion that Alzheimer’s disease is a heterogeneous disorder.
|
|
| 5. |
- Wiig, Elisabeth H, et al.
(författare)
-
Parietal lobe activation in rapid, automatized naming by adults.
- 2002
-
Ingår i: Perceptual and Motor Skills. - 0031-5125 .- 1558-688X. ; 94:3 Pt 2, s. 1230-44
-
Tidskriftsartikel (refereegranskat)abstract
- Three automatic naming tasks (Wiig & Nielsen, 1999) were administered to 60 normally functioning adults. The mean time required for naming 40 single-dimension (colors, forms, numbers, and letters) and 40 dual-dimension stimuli (color-form, color-number, and color-letter combinations) were compared in young (17-38 yr.) and older (40-68 yr.) men and women. Analysis of variance for the combined groups indicated significant naming-time differences for age but not for sex. There were no significant interaction effects. For men there was a significant naming time difference between age groups for forms, and for women for colors and forms. The sex-specific analyses indicated no significant differences in naming time based on age groups for color-form, color-number, or color-letter combinations. In a second study of adult subjects (n = 14), functional brain activity was measured with regional cerebral blood flow during the performance of the color, form, and color-form naming tasks. One subject was repeatedly measured during the performance of each task, whereas 13 subjects were measured during the performance of color-form naming. In comparison to normal reference values for rest and FAS verbal fluency, blood-flow measurements showed a consistent parietal-lobe activation during form and color-form naming, but only a slight activation during color naming. During all naming tasks, a significant frontal and frontotemporal flow decrease was seen in comparison to both rest and verbal fluency reference values. This functional brain activation pattern of a parietal increase and a frontotemporal decrease was consistently confirmed across subjects during the color-form naming task.
|
|
