Harry Uylings

Publications (192) View all

• Source

  Available from: Harry Uylings

  Dataset: SaartjeWMageDifferNI2010corrigendum

  S Burgmans, M P J van Boxtel, E H B M Gronenschild, E F P M Vuurman, P Hofman, H B M Uylings, J Jolles, N Raz
• Article: PPatterns of gray and white matter changes in individuals at risk for Alzheimer's disease.

  H I L Jacobs, M P J van Boxtel, E H B M Gronenschild, V J Williams, S Burgmans, H B M Uylings, J Jolles, F R J Verhey
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  ABSTRACT: Structural brain changes precede cognitive and clinical symptoms in Alzheimer's disease (AD). We aimed to examine the gray and white matter tissue changes in individuals with memory decline over a 12-year period, who might be at risk for AD. The participants were selected from the longitudinal Maastricht Aging Study based on their scores on the verbal word learning task. A group with profound memory decline over a 12-year period (n = 20) was identified and matched with a group that did not meet this criterion (n = 20). All of the participants underwent MRI scanning. Diffusion tensor imaging and cortical thickness analyses were performed to investigate the white and gray matter differences respectively. We found decreased white matter integrity in the memory decline group compared to the control group in frontal and parietal brain regions and in several corticocortical and cortico-subcortical tracts. Cortical thinning in the memory decline group was found in frontal, parietal, medial temporal and occipital areas. These results showed similarities with the structural brain changes observed in early AD. Thus, not only may cognitive changes be detected years before the clinical diagnosis, but typical gray and white matter changes appear to be present in older people with memory decline as well. This suggests that a combination of cognitive decline and structural brain changes might be an ideal biomarker for AD pathogenesis.
  Current Alzheimer research 08/2012; · 4.97 Impact Factor
• Article: Atrophy in the parahippocampal gyrus as an early biomarker of Alzheimer’s disease

  C. Echávarri, P. Aalten, H. B. M. Uylings, H. I. L. Jacobs, P. J. Visser, E. H. B. M. Gronenschild, F. R. J. Verhey, S. Burgmans
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  ABSTRACT: The main aim of the present study was to compare volume differences in the hippocampus and parahippocampal gyrus as biomarkers of Alzheimer’s disease (AD). Based on the previous findings, we hypothesized that there would be significant volume differences between cases of healthy aging, amnestic mild cognitive impairment (aMCI), and mild AD. Furthermore, we hypothesized that there would be larger volume differences in the parahippocampal gyrus than in the hippocampus. In addition, we investigated differences between the anterior, middle, and posterior parts of both structures. We studied three groups of participants: 18 healthy participants without memory decline, 18 patients with aMCI, and 18 patients with mild AD. 3T T1-weighted MRI scans were acquired and gray matter volumes of the anterior, middle, and posterior parts of both the hippocampus and parahippocampal gyrus were measured using a manual tracing approach. Volumes of both the hippocampus and parahippocampal gyrus were significantly different between the groups in the following order: healthy>aMCI>AD. Volume differences between the groups were relatively larger in the parahippocampal gyrus than in the hippocampus, in particular, when we compared healthy with aMCI. No substantial differences were found between the anterior, middle, and posterior parts of both structures. Our results suggest that parahippocampal volume discriminates better than hippocampal volume between cases of healthy aging, aMCI, and mild AD, in particular, in the early phase of the disease. The present results stress the importance of parahippocampal atrophy as an early biomarker of AD. KeywordsAlzheimer’s disease–Cognitive aging–Mild cognitive impairment–Volumetric magnetic resonance image
  Brain Structure and Function 04/2012; 215(3):265-271. · 5.63 Impact Factor
• Article: Cognitieve veroudering en veranderingen in de structuur en functie van de hersenen: een nieuw perspectief

  S. Burgmans, J. Jolles, H.B.M. Uylings
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  ABSTRACT: Het klassieke beeld van veroudering is dat het aantal zenuwcellen in de hersenschors tot de helft afneemt en dat de zenuwceluitlopers van de overgebleven zenuwcellen grotendeels wegvallen startend vanaf ongeveer het zestigste levensjaar. In de laatste decennia is met behulp van histologisch onderzoek echter aangetoond dat het aantal zenuwcellen in de menselijke hersenschors slechts in geringe mate afneemt en dat de zenuwceluitlopers grotendeels intact blijven. Ook recent imaging (hersenscan)-onderzoek laat zien dat het beeld nu wijzigt ten aanzien van veranderingen in de hersenen bij veroudering: de afname van de hersenstructuren blijkt bij normale veroudering veel minder dan aanvankelijk werd gedacht. Dit artikel beschrijft nieuwe inzichten en klinische implicaties voortkomend uit onderzoek naar het oudere brein. Het geeft een overzicht van veranderingen in de structuur en functie van de hersenen en de samenhang met cognitieve veroudering.
  04/2012; 2010(3):59-63.
• Article: Age differences in speed of processing are partially mediated by differences in axonal integrity.

  S Burgmans, E H B M Gronenschild, Y Fandakova, Y L Shing, M P J van Boxtel, E F P M Vuurman, H B M Uylings, J Jolles, N Raz
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  ABSTRACT: Advanced age is associated with declines in brain structure and in cognitive performance, but it is unclear which aspects of brain aging mediate cognitive declines. We inquired if individual differences in white matter integrity contribute to age differences in two cognitive domains with established vulnerability to aging: executive functioning and speed of processing. The participants were healthy volunteers aged 50-81, some of whom had elevated blood pressure, a known vascular risk factor. Using latent variable analyses, we examined whether age differences in regional white matter integrity mediated age-related differences in executive functions and speed of processing. Although diffusion-related latent variables showed stronger age differences than white matter volumes and white matter hyperintensity volumes, only one of them was significantly associated with cognitive performance. Smaller linear anisotropy partially mediated age-related reduction in speed of processing. The effect was significant in posterior (temporal-parietal-occipital) but not anterior (frontal) region, and appeared stronger for cognitive rather than reaction time measures of processing speed. The presence of hypertensive participants did not affect the results. We conclude that in healthy adults, deterioration of axonal integrity and ensuing breech of connectivity may underpin age-related slowing of information processing.
  NeuroImage 01/2011; 55(3):1287-97. · 5.89 Impact Factor