| 1. |
- Hägerström, Douglas, et al.
(författare)
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A new automated method for analysis of rCBF-SPECT images based on the active-shape algorithm: Normal values
- 2012
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Ingår i: Clinical Physiology and Functional Imaging. - 1475-0961 .- 1475-097X. ; 32, s. 114-119
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Tidskriftsartikel (refereegranskat)abstract
- Most nuclear medicine clinicians use only visual assessment when interpreting regional cerebral blood flow (rCBF) from single-photon emission computed tomography (SPECT) images in clinical practice. The aims of this study were to develop a new, easy to use, automated method for quantification of rCBF-SPECT and to create normal values by using the method on a normal population. We developed a 3-dimensional method based on a brain-shaped model and the active-shape algorithm. The method defines the surface shape of the brain and then projects the maximum counts 0-1·5cm deep for designated surface points. These surface projection values are divided into cortical regions representing the different lobes and presented relative to the whole cortex, cerebellum or cerebellar maximum.99mTc-hexa methyl propylene amine oxime (HMPAO) SPECT was performed on 30 healthy volunteers with a mean age of 74years (range 64-98). The ability of the active-shape algorithm to define the shape of the brain was satisfactory when visually scrutinized. The results of the quantification show rCBF values in the frontal, temporal and parietal lobes of 87-88% using cerebellum as the reference. There were no significant differences in normal rCBF values between male and female subjects and only a weak relation between rCBF and age. In conclusion, our new automated method was able to quantify rCBF-SPECT images and create normal values in ranges as expected. Further studies are needed to assess the clinical value of this method and the normal values. © 2011 The Authors. Clinical Physiology and Functional Imaging © 2011 Scandinavian Society of Clinical Physiology and Nuclear Medicine.
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| 2. |
- Stomrud, Erik, et al.
(författare)
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CSF biomarkers correlate with cerebral blood flow on SPECT in healthy elderly.
- 2012
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Ingår i: Dementia and geriatric cognitive disorders. - : S. Karger AG. - 1421-9824 .- 1420-8008. ; 33:2-3, s. 156-63
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Tidskriftsartikel (refereegranskat)abstract
- The preclinical patterns of biological markers for Alzheimer's disease (AD) in vivo need further exploration. The aim of this study was therefore to investigate CSF biomarkers, regional cerebral blood flow (rCBF) and cognitive performance in cognitively healthy older individuals.
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| 3. |
- Hansson, Oskar, et al.
(författare)
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Evaluation of Plasma A beta as Predictor of Alzheimer's Disease in Older Individuals Without Dementia: A Population-Based Study
- 2012
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Ingår i: Journal of Alzheimer's Disease. - 1387-2877 .- 1875-8908. ; 28:1, s. 231-238
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Tidskriftsartikel (refereegranskat)abstract
- Amyloid-beta (A beta) pathology is a major component in the mechanisms behind Alzheimer's disease (AD). Measurement of A beta(42) in cerebrospinal fluid predicts cognitive decline in patients with mild cognitive impairment and identifies AD in patients with dementia. However, studies on A beta in plasma are contradictory. In this prospective population-based study, plasma A beta(42) and A beta(40) were measured at baseline in 730 adults aged 70 years or older and without dementia. After five years, plasma levels were analyzed again and participants were assessed for development of dementia. During follow-up, 53 individuals (7%) developed dementia of which 37 (5%) were classified as AD. No difference in baseline plasma A beta(42), A beta(40), or A beta(42)/A beta(40) ratio levels were observed between converters to dementia or AD compared to the cognitively stable individuals. However, individuals with plasma A beta(40) levels above the median level for the group at baseline had an increased risk of developing dementia and AD during the follow-up, even after adjustment for age, gender, APOE genotype, and educational level (odds ratio = 2.2, 95% confidence interval = 1.0-4.7, p < 0.05). Neither plasma A beta(42) nor the A beta(42)/A beta(40) ratio influenced the risk of developing dementia or AD. Moreover, A beta(42) and A beta(40) levels increased over the 5 years, whereas the A beta(42)/A beta(40) ratio decreased (p < 0.001). In conclusion, this study suggests that measurement of plasma A beta should not be used clinically to predict dementia or AD. However, plasma A beta(40) may possibly be regarded as a moderate risk marker comparable to other risk markers for AD such as first-degree family history of dementia.
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| 4. |
- Stomrud, Erik, et al.
(författare)
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Alterations of matrix metalloproteinases in the healthy elderly with increased risk of prodromal Alzheimer's disease
- 2010
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Ingår i: Alzheimer's Research & Therapy. - : Springer Science and Business Media LLC. - 1758-9193. ; 2:3, s. 20-20
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Tidskriftsartikel (refereegranskat)abstract
- INTRODUCTION: Matrix metalloproteinases (MMP) are believed to be involved in the pathologic processes behind Alzheimer's disease (AD). In this study, we aimed to examine the cerebrospinal fluid (CSF) levels of MMPs and tissue inhibitors of metalloproteinase-1 (TIMP-1) in individuals with AD dementia and cognitively healthy elderly individuals, and to investigate their relationship with established CSF biomarkers for Alzheimer's disease.METHODS: CSF was collected from 38 individuals with AD dementia and 34 cognitively healthy elderly individuals. The CSF was analyzed for MMP-1, MMP-3, MMP-9, TIMP-1, beta-amyloid1-42 (Abeta42), total tau protein (T-tau) and phosphorylated tau protein (P-tau). MMP/TIMP-1 ratios were calculated. APOE genotype was determined for the participants.RESULTS: AD patients had higher MMP-9/TIMP-1 ratios and lower TIMP-1 levels compared to cognitively healthy individuals. In AD patients, the MMP-9/TIMP-1 ratio correlated with CSF T-tau, a marker of neurodegeneration. Interestingly, the cognitively healthy individuals with risk markers for future AD, i.e. AD-supportive CSF biomarker levels of T-tau, P-tau and Abeta42 or the presence of the APOE epsilon4 allele, had higher CSF MMP-3 and MMP-9 levels and higher CSF MMP-3/TIMP-1 ratios compared to the healthy individuals without risk markers. The CSF levels of MMP-3 and -9 in the control group also correlated with the CSF T-tau and P-tau levels.CONCLUSIONS: This study indicates that MMP-3 and MMP-9 might be involved in early pathogenesis of AD and that MMPs could be associated with neuronal degeneration and formation of neurofibrillary tangles even prior to development of overt cognitive dysfunction.
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| 5. |
- Stomrud, Erik, et al.
(författare)
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Correlation of longitudinal cerebrospinal fluid biomarkers with cognitive decline in healthy older adults.
- 2010
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Ingår i: Archives of neurology. - : American Medical Association (AMA). - 1538-3687 .- 0003-9942. ; 67:2, s. 217-23
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Abnormal cerebrospinal fluid (CSF) biomarker levels predict development of Alzheimer disease with good accuracy and are thought to precede cognitive deterioration. OBJECTIVE: To investigate whether changes in CSF biomarker levels over time in healthy older adults are associated with a concurrent decline in cognitive performance. DESIGN: Retrospective analysis of longitudinal CSF biomarker levels and clinical data. SETTING: A combined academic dementia disorder research center and dementia clinic. PARTICIPANTS: Thirty-seven cognitively healthy older volunteers (mean age, 73 years). MAIN OUTCOME MEASURES: Longitudinal CSF total tau protein, hyperphosphorylated tau protein 181, and beta-amyloid(1-42) protein levels and cognitive assessments at baseline and at follow-up 4 years later. RESULTS: Low levels of CSF beta-amyloid(1-42) protein at follow-up were associated with decreased delayed word recall score on the Alzheimer Disease Assessment Scale-cognitive subscale (r(s) = -0.437, P < .01) and with slower results on A Quick Test of Cognitive Speed (r(s) = -0.540, P < .001). Individuals with a decrease during the 4-year study of 15% or more in CSF beta-amyloid(1-42) protein level performed worse on the Alzheimer Disease Assessment Scale-cognitive subscale delayed word recall (z = -2.18, P < .05) and A Quick Test of Cognitive Speed (z = -2.35, P < .05) at follow-up. An increase over time of 20% or more in CSF hyperphosphorylated tau protein 181 level correlated with slower results on A Quick Test of Cognitive Speed at follow-up (z = -2.13, P < .05). Furthermore, the presence of the APOE-epsilon4 (OMIM 107741) allele was associated with a greater longitudinal decrease in CSF beta-amyloid(1-42) protein level (chi(2) = 10.47, P < .05) and with a higher CSF total tau protein level at follow-up (chi(2) = 8.83, P < .05). No correlation existed between baseline CSF biomarker levels and baseline or follow-up cognitive scores. CONCLUSIONS: In this group of healthy older adults, changes in CSF biomarker levels previously associated with Alzheimer disease correlated with a decline in cognitive functions. Changes in CSF biomarker levels may identify early neurodegenerative processes of Alzheimer disease.
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| 6. |
- Stomrud, Erik, et al.
(författare)
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Slowing of EEG correlates with CSF biomarkers and reduced cognitive speed in elderly with normal cognition over 4 years.
- 2010
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Ingår i: Neurobiology of aging. - : Elsevier BV. - 1558-1497 .- 0197-4580. ; 31:2, s. 215-23
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Tidskriftsartikel (refereegranskat)abstract
- Cerebrospinal fluid (CSF) biomarkers and quantitative EEG show particular patterns of change in Alzheimer's disease (AD) and reflect neuropathologic processes and cerebral function, respectively. The changes precede cognitive decline and should be visible already in preclinical stages. We therefore aimed to investigate their relationship in cognitively healthy individuals.
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| 7. |
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