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Being physically active is associated with improved executive function and processing speed but not memory: The LADIS study
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Abstracts / Journal of the Neurological Sciences 333 (2013) e292–e357
connectivity of brain network. The default mode network (DMN) is one of prominent networks, which include the hippocampus, posterior cingulate (PCC), medial prefrontal, lateral temporal, and parietal cortices. Many studies found decreased DMN connectivity in Alzheimer's disease (AD) and suggested distinct involvement of DMN in different types of dementia. Objective: We aimed to differentiate normal pressure hydrocephalus (NPH) from AD on the basis of neural connectivity with rs-fMRI, because these two diseases are sometimes difficult to discriminate only on the morphological examination. Patients and method: Subjects diagnosed as having probable NPH (n = 9; mean age 77.4 ± 4.1 years, range 69–80 years), AD (n = 27; mean age 76.5 ± 5.0 years, range 66–86 years), and 57 healthy controls (HC, n = 57; mean age 67.3 ± 5.2 years, range 61–79 years, MMSE ≧ 27) underwent rs-fMRI. We used PCC as a seed region to determine the functional connectivity to other brain regions in DMN. Results: The functional connectivity between PCC and other brain regions in DMN was decreased in both NPH and AD groups compared to HC group (p b 0.001), and there was no difference in the connectivity between NPH and AD groups. Conclusion: Our findings indicate that the functional connectivity in DMN decreased in NPH as well as AD. However, it is difficult to differentiate NPH from AD on the basis of functional connectivity with rs-fMRI using seed-based analysis. doi:10.1016/j.jns.2013.07.1298
Abstract — WCN 2013 No: 2834 Topic: 5 — Dementia Cortical beta-amyloid and microstructural properties of the corpus callosum in patients with mild to moderate ad K.S. Frederiksena,b, N. Resilevb, S.G. Hasselbalcha,c, I. Lawd, K. Madsenc, T.B. Dyrbyb, E. Gardeb, H. Siebnerb, G. Waldemara. a Danish Dementia Research Centre, Copenhagen University Hospital, Rigshospitalet, Copenhagen, Denmark; bDanish Research Center for Magnetic Resonance, Copenhagen University Hospital, Hvidovre, Denmark; cNeurobiology Research Unit, Denmark; dDepartment of Physiology, Nuclear Medicine and PET, Copenhagen University Hospital, Rigshospitalet, Copenhagen, Denmark Background: Several studies have reported microstructural changes of the corpus callosum (CC) in AD. The pathological basis of these changes remains uncertain. Objective: We investigated whether fractional anisotropy (FA) as a marker of microstructural properties of the CC is associated with cortical beta-amyloid measured by amyloid imaging. Methods: Patients with mild to moderate Alzheimer's dementia (according to NINCDS-ADRDA criteria and ICD-10 criteria), were recruited. Patients underwent 11C-PiB-PET for assessment of cortical betaamyloid and MRI (Siemens Magnetom Trio 3T) including DWI for quantification of white matter microstructure. DWI data were fitted to the tensor model, and FA maps were created. Masks were manually delineated on the midsagittal slice of the FA maps, encompassing the anterior 1/6th of the CC (projecting to prefrontal cortex) and the posterior 1/4th (projecting to parietal, temporal, occipital cortices). For quantification of beta-amyloid standard uptake value ratios (SUVR) from prefrontal cortex, and parietal, occipital and temporal cortices were used in the analysis. Results: Thirty-two patients (age, years: 69.2 (±7.3); Gender (f/m): 14/18; MMSE: 24.8 (3.5)) were included in the study. Mean FA across subjects for anterior CC was 0.74 (±0.038) and for posterior CC 0.71 (±0.068). No significant associations between FA in anterior
CC and prefrontal 11C-PiB uptake or between FA in posterior CC and parietal–temporal–occipital cortex 11C-PiB uptake was found. Conclusion: Cortical deposition of beta-amyloid does not seem to be the underlying mechanism of microstructural changes in the CC in AD patients. However, whether beta-amyloid may affect the CC through cortical atrophy remains undecided.
doi:10.1016/j.jns.2013.07.1299
Abstract — WCN 2013 No: 2836 Topic: 5 — Dementia Being physically active is associated with improved executive function and processing speed but not memory: The LADIS study K. Frederiksena, A. Verdelhob, S. Madureirab, H. Bäznerc, J.T. O'Briend, F. Fazekase, P. Scheltensf, R. Schmidte, A. Walling, L.-O. Wahlundg, T. Erkinjunttih, A. Poggesii, L. Pantonii, D. Inzitarii, G. Waldemara, on behalf of the LADIS study a Danish Dementia Research Centre, Copenhagen University Hospital, Rigshospitalet, Copenhagen, Denmark; bDept. of Neurosciences, University of Lisbon, Lisbon, Portugal; cDept. of Neurology, University of Heidelberg, Mannheim, Germany; dInstitute for Ageing and Health, Newcastle University, Newcastle-Upon-Tyne, UK; eDepartment of Neurology and MRI Institute, Karl Franzens University Graz, Graz, Austria; fDept. of Neurology, VU University Medical Center, Amsterdam, The Netherlands; gInstitute of Clinical Neurosciences, NEUROTEC, Karolinska Institutet, Huddinge University Hospital, Stockholm, Sweden; hMemory Research Unit, Department of Clinical Neurosciences, Helsinki University, Helsinki, Finland; iDepartment of Neurological and Psychiatric Sciences, University of Florence, Florence, Italy Background: Physical activity (PA) reduces the risk of cognitive decline, but may affect cognitive domains differently. Objective: We examined whether PA may differentially modify processing speed, executive function and memory in a population of dementia-free elderly subjects with age-related white matter changes (ARWMC). Patients and methods: Data from the Leukoaraiosis And DISability (LADIS) study, a multicenter, European prospective cohort study aimed at examining the role of ARWMC in transition to disability, was used. Subjects in the LADIS study were clinically assessed yearly for 3 years including MRI at baseline and 3-year follow-up. PA was assessed at baseline. Cognitive composite scores at baseline and 3-year assessment were used. Results: Two-hundred-eighty-two subjects (age, y (mean (SD)): 73.1 (±5.1); gender (f/m): 164/118); MMSE (mean (SD)): 28.3 (±1.7) who had not progressed to dementia or MCI, were included. A multiple variable linear regression analysis with baseline MMSE, education, gender, age, stroke, diabetes and ARWMC rating as covariates revealed that PA was associated with better scores at baseline and 3-year follow-up for executive function (baseline: β:0.39, 95% CI: 0.13–0.90, p = 0.008; follow-up: β:0.24, 95% CI: 0.10–0.38, p = 0.001) and processing speed (baseline: β:0.48, 95% CI: 0.14–0.89, p = 0.005; follow-up: β: 0.15, 95% CI: 0.02–0.29, p = 0.02) but not memory. When including baseline cognitive score as a covariate in the analysis for 3-year follow-up scores, executive function remained significant (p = 0.04). Conclusion: PA is associated with preserved executive function and processing speed but not memory in elderly dementia-free subjects with ARWMC.
doi:10.1016/j.jns.2013.07.1300
Abstracts / Journal of the Neurological Sciences 333 (2013) e292–e357
connectivity of brain network. The default mode network (DMN) is one of prominent networks, which include the hippocampus, posterior cingulate (PCC), medial prefrontal, lateral temporal, and parietal cortices. Many studies found decreased DMN connectivity in Alzheimer's disease (AD) and suggested distinct involvement of DMN in different types of dementia. Objective: We aimed to differentiate normal pressure hydrocephalus (NPH) from AD on the basis of neural connectivity with rs-fMRI, because these two diseases are sometimes difficult to discriminate only on the morphological examination. Patients and method: Subjects diagnosed as having probable NPH (n = 9; mean age 77.4 ± 4.1 years, range 69–80 years), AD (n = 27; mean age 76.5 ± 5.0 years, range 66–86 years), and 57 healthy controls (HC, n = 57; mean age 67.3 ± 5.2 years, range 61–79 years, MMSE ≧ 27) underwent rs-fMRI. We used PCC as a seed region to determine the functional connectivity to other brain regions in DMN. Results: The functional connectivity between PCC and other brain regions in DMN was decreased in both NPH and AD groups compared to HC group (p b 0.001), and there was no difference in the connectivity between NPH and AD groups. Conclusion: Our findings indicate that the functional connectivity in DMN decreased in NPH as well as AD. However, it is difficult to differentiate NPH from AD on the basis of functional connectivity with rs-fMRI using seed-based analysis. doi:10.1016/j.jns.2013.07.1298
Abstract — WCN 2013 No: 2834 Topic: 5 — Dementia Cortical beta-amyloid and microstructural properties of the corpus callosum in patients with mild to moderate ad K.S. Frederiksena,b, N. Resilevb, S.G. Hasselbalcha,c, I. Lawd, K. Madsenc, T.B. Dyrbyb, E. Gardeb, H. Siebnerb, G. Waldemara. a Danish Dementia Research Centre, Copenhagen University Hospital, Rigshospitalet, Copenhagen, Denmark; bDanish Research Center for Magnetic Resonance, Copenhagen University Hospital, Hvidovre, Denmark; cNeurobiology Research Unit, Denmark; dDepartment of Physiology, Nuclear Medicine and PET, Copenhagen University Hospital, Rigshospitalet, Copenhagen, Denmark Background: Several studies have reported microstructural changes of the corpus callosum (CC) in AD. The pathological basis of these changes remains uncertain. Objective: We investigated whether fractional anisotropy (FA) as a marker of microstructural properties of the CC is associated with cortical beta-amyloid measured by amyloid imaging. Methods: Patients with mild to moderate Alzheimer's dementia (according to NINCDS-ADRDA criteria and ICD-10 criteria), were recruited. Patients underwent 11C-PiB-PET for assessment of cortical betaamyloid and MRI (Siemens Magnetom Trio 3T) including DWI for quantification of white matter microstructure. DWI data were fitted to the tensor model, and FA maps were created. Masks were manually delineated on the midsagittal slice of the FA maps, encompassing the anterior 1/6th of the CC (projecting to prefrontal cortex) and the posterior 1/4th (projecting to parietal, temporal, occipital cortices). For quantification of beta-amyloid standard uptake value ratios (SUVR) from prefrontal cortex, and parietal, occipital and temporal cortices were used in the analysis. Results: Thirty-two patients (age, years: 69.2 (±7.3); Gender (f/m): 14/18; MMSE: 24.8 (3.5)) were included in the study. Mean FA across subjects for anterior CC was 0.74 (±0.038) and for posterior CC 0.71 (±0.068). No significant associations between FA in anterior
CC and prefrontal 11C-PiB uptake or between FA in posterior CC and parietal–temporal–occipital cortex 11C-PiB uptake was found. Conclusion: Cortical deposition of beta-amyloid does not seem to be the underlying mechanism of microstructural changes in the CC in AD patients. However, whether beta-amyloid may affect the CC through cortical atrophy remains undecided.
doi:10.1016/j.jns.2013.07.1299
Abstract — WCN 2013 No: 2836 Topic: 5 — Dementia Being physically active is associated with improved executive function and processing speed but not memory: The LADIS study K. Frederiksena, A. Verdelhob, S. Madureirab, H. Bäznerc, J.T. O'Briend, F. Fazekase, P. Scheltensf, R. Schmidte, A. Walling, L.-O. Wahlundg, T. Erkinjunttih, A. Poggesii, L. Pantonii, D. Inzitarii, G. Waldemara, on behalf of the LADIS study a Danish Dementia Research Centre, Copenhagen University Hospital, Rigshospitalet, Copenhagen, Denmark; bDept. of Neurosciences, University of Lisbon, Lisbon, Portugal; cDept. of Neurology, University of Heidelberg, Mannheim, Germany; dInstitute for Ageing and Health, Newcastle University, Newcastle-Upon-Tyne, UK; eDepartment of Neurology and MRI Institute, Karl Franzens University Graz, Graz, Austria; fDept. of Neurology, VU University Medical Center, Amsterdam, The Netherlands; gInstitute of Clinical Neurosciences, NEUROTEC, Karolinska Institutet, Huddinge University Hospital, Stockholm, Sweden; hMemory Research Unit, Department of Clinical Neurosciences, Helsinki University, Helsinki, Finland; iDepartment of Neurological and Psychiatric Sciences, University of Florence, Florence, Italy Background: Physical activity (PA) reduces the risk of cognitive decline, but may affect cognitive domains differently. Objective: We examined whether PA may differentially modify processing speed, executive function and memory in a population of dementia-free elderly subjects with age-related white matter changes (ARWMC). Patients and methods: Data from the Leukoaraiosis And DISability (LADIS) study, a multicenter, European prospective cohort study aimed at examining the role of ARWMC in transition to disability, was used. Subjects in the LADIS study were clinically assessed yearly for 3 years including MRI at baseline and 3-year follow-up. PA was assessed at baseline. Cognitive composite scores at baseline and 3-year assessment were used. Results: Two-hundred-eighty-two subjects (age, y (mean (SD)): 73.1 (±5.1); gender (f/m): 164/118); MMSE (mean (SD)): 28.3 (±1.7) who had not progressed to dementia or MCI, were included. A multiple variable linear regression analysis with baseline MMSE, education, gender, age, stroke, diabetes and ARWMC rating as covariates revealed that PA was associated with better scores at baseline and 3-year follow-up for executive function (baseline: β:0.39, 95% CI: 0.13–0.90, p = 0.008; follow-up: β:0.24, 95% CI: 0.10–0.38, p = 0.001) and processing speed (baseline: β:0.48, 95% CI: 0.14–0.89, p = 0.005; follow-up: β: 0.15, 95% CI: 0.02–0.29, p = 0.02) but not memory. When including baseline cognitive score as a covariate in the analysis for 3-year follow-up scores, executive function remained significant (p = 0.04). Conclusion: PA is associated with preserved executive function and processing speed but not memory in elderly dementia-free subjects with ARWMC.
doi:10.1016/j.jns.2013.07.1300