Stijn Michielse

Publications (2)11.52 Total impact

• Article: Structural organization of the prefrontal white matter pathways in the adult and aging brain measured by diffusion tensor imaging.

  Nikolai Malykhin, Sana Vahidy, Stijn Michielse, Nick Coupland, Richard Camicioli, Peter Seres, Rawle Carter
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  ABSTRACT: Previous diffusion tensor imaging (DTI) studies confirmed the vulnerability of frontal callosal fibers to normal aging. The present study extended this examination systematically to other prefrontal white matter regions. Structural magnetic resonance imaging and DTI datasets were acquired from 69 healthy subjects aged 22-84 years. The prefrontal white matter was parcellated into several anatomical sub-regions: medial and lateral orbitofrontal white matter, dorsolateral prefrontal white matter, and medial prefrontal white matter, using reliable DTI-tractography protocols. Tract-specific characteristics were calculated using Matlab. Regression models were used to determine the relationship between age and structural integrity of white matter tracts. The results of our study demonstrate regional age-related changes in the prefrontal white matter tracts of the human brain. This study was cross-sectional and therefore additional longitudinal studies are needed to confirm our findings.
  Brain Structure and Function 05/2011; 216(4):417-31. · 5.63 Impact Factor
• Article: Selective effects of aging on brain white matter microstructure: a diffusion tensor imaging tractography study.

  Stijn Michielse, Nick Coupland, Richard Camicioli, Rawle Carter, Peter Seres, Jennifer Sabino, Nikolai Malykhin
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  ABSTRACT: We examined age-related changes in the cerebral white matter. Structural magnetic resonance images (MRIs) and diffusion tensor images (DTIs) were acquired from 69 healthy subjects aged 22-84 years. Quantitative DTI tractography was performed for nine different white matter tracts to determine tract volume, fractional anisotropy (FA), mean diffusivity (MD), axial, and radial diffusivities. We used automated and manual segmentation to determine volumes of gray matter (GM), white mater (WM), cerebrospinal fluid (CSF), and intracranial space. The results showed significant effects of aging on WM, GM, CSF volumes, and selective effects of aging on structural integrity of different white matter tracts. WM of the prefrontal region was the most vulnerable to aging, while temporal lobe connections, cingulum, and parieto-occipital commissural connections showed relative preservation with age. This study was cross-sectional, and therefore, additional longitudinal studies are needed to confirm our findings.
  NeuroImage 10/2010; 52(4):1190-201. · 5.89 Impact Factor