on behalf of the European Task Force on Age-Related White Matter Changes Background and Purpose-MRI is more sensitive than CT for detection of age-related white matter changes (ARWMC).Most rating scales estimate the degree and distribution of ARWMC either on CT or on MRI, and they differ in many aspects. This makes it difficult to compare CT and MRI studies. To be able to study the evolution and possible effect of drug treatment on ARWMC in large patient samples, it is necessary to have a rating scale constructed for both MRI and CT. We have developed and evaluated a new scale and studied ARWMC in a large number of patients examined with both MRI and CT. Methods-Seventy-seven patients with ARWMC on either CT or MRI were recruited and a complementary examination (MRI or CT) performed. The patients came from 4 centers in Europe, and the scans were rated by 4 raters on 1 occasion with the new ARWMC rating scale. The interrater reliability was evaluated by using statistics. The degree and distribution of ARWMC in CT and MRI scans were compared in different brain areas. Results-Interrater reliability was good for MRI (ϭ0.67) and moderate for CT (ϭ0.48). MRI was superior in detection of small ARWMC, whereas larger lesions were detected equally well with both CT and MRI. In the parieto-occipital and infratentorial areas, MRI detected significantly more ARWMC than did CT. In the frontal area and basal ganglia, no differences between modalities were found. When a fluid-attenuated inversion recovery sequence was used, MRI detected significantly more lesions than CT in frontal and parieto-occipital areas. No differences were found in basal ganglia and infratentorial areas. Conclusions-We present a new ARWMC scale applicable to both CT and MRI that has almost equal sensitivity, except for certain regions. The interrater reliability was slightly better for MRI, as was the detectability of small lesions. Key Words: dementia Ⅲ magnetic resonance imaging Ⅲ rating scales Ⅲ tomography, x-ray computed Ⅲ white matter W hite matter changes (WMC) are defined as areas with high signal intensities on T2-weighted MRI and as areas with low attenuation on CT. The mechanisms for development of WMC are not fully understood, but several histopathologic correlates have been reported. These include enlarged perivascular (Virchow-Robin) spaces, as well as degeneration of myelin and axons with increased intracellular and extracellular water content, gliosis, and even infarction. [1][2][3][4][5][6][7][8][9][10] The clinical significance of WMC has not been fully elucidated. There is a relationship between several cerebrovascular risk factors and the presence of WMC. One of the strongest risk factors, apart from hypertension, is that of age. 11-13 Henceforth, we will designate WMC as "age-related white matter changes" (ARWMC).There is also evidence for a relationship between ARWMC and cognitive impairment in demented patients 14 -16 as well as in healthy elderly individuals. 13,[17][18][19] However, the extent of this association is still controv...

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High cholesterol in late life was associated with decreased dementia risk, which is in contrast to previous studies suggesting high cholesterol in mid-life is a risk factor for later dementia. The conflicting results may be explained by the timing of the cholesterol measurements in relationship to age and the clinical onset of dementia.

Background: Tau protein and the 42-amino acid form of β-amyloid (Aβ42) measured in cerebrospinal fluid (CSF) have been proposed as potential biochemical diagnostic markers for Alzheimer disease. For the introduction of these assays in clinical practice, adequate reference values are of importance. Methods: CSF samples were obtained from 231 neurologically and psychiatrically healthy individuals, 21–93 years of age, all with a MiniMental State examination score of 28 or above. Standardized ELISAs were used to measure tau and Aβ42 in CSF. Following IFCC recommendations, we used a rank-based method; the 0.90 and 0.10 fractiles were estimated to establish reference values for CSF-tau and CSF-Aβ42, respectively. Putative confounding factors, such as the influence of the passage of proteins from peripheral blood to CSF, influence of dysfunction of the blood-brain barrier, and freezing and thawing of CSF, were investigated. Results: A correlation with age was found for CSF-tau (r = 0.60; P <0.001). Therefore, separate reference values for different age groups were established for CSF-tau: <300 ng/L in the group 21–50 years of age, <450 ng/L in the group 51–70 years of age, and <500 ng/L in the group 71–93 years of age. CSF-Aβ42 did not correlate with age (r = −0.045), and the reference value was set to >500 ng/L. No correlation was found between blood-brain barrier function and CSF-tau or CSF-Aβ42. Conclusions: These reference values can be applied when using CSF-tau and CSF-Aβ42 in clinical practice.

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