title: Age-related microstructural changes in subcortical white matter during postadolescent periods in men revealed by diffusion-weighted MR imaging.
abstract: Continuous maturation of cerebral white matter (WM) in the postadolescent period is not fully understood. To elucidate the time course and location of possible postadolescent maturational changes in cerebral WM, we studied 60 healthy male subjects who were in their second to seventh decade using diffusion-weighted imaging. Mean diffusivity (MD) in subcortical WM was measured in 78 cortical regions in each subject's brain using an automated method. Regression analysis was used to model the age-related change in MD by either a linear or a quadratic function in each region. Age-related changes in subcortical MD were best modeled by either a linear function or a quadratic function in 27 regions including language-related regions, visual or multimodal areas in the bilateral occipital and temporal lobes, limbic areas including the bilateral parahippocampal gyri, and the bilateral postcentral and left precentral gyri. In these regions, the MD rapidly decreased until middle age and thereafter reached a plateau. Our results revealed microstructural changes in local subcortical WM and suggests a continuing maturational process in postoadolescent periods.
authors.affiliation: Department of Clinical Radiology, Graduate School of Medical Sciences, Kyushu University, Higashi-ku, Fukuoka 812-8582, Japan. tyoshiu@med.kyushu-u.ac.jp
authors.forename: Takashi
authors.initials: T
authors.lastname: Yoshiura
authors.forename: Tomoyuki
authors.initials: T
authors.lastname: Noguchi
authors.forename: Akio
authors.initials: A
authors.lastname: Hiwatashi
authors.forename: Osamu
authors.initials: O
authors.lastname: Togao
authors.forename: Koji
authors.initials: K
authors.lastname: Yamashita
authors.forename: Tomohiro
authors.initials: T
authors.lastname: Nakao
authors.forename: Eiki
authors.initials: E
authors.lastname: Nagao
authors.forename: Seiji
authors.initials: S
authors.lastname: Kumazawa
authors.forename: Hidetaka
authors.initials: H
authors.lastname: Arimura
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Honda
mesh_terms: D000293:Adolescent; D000375:Aging / Q000502:physiology*; D001931:Brain Mapping; D002540:Cerebral Cortex / Q000033:anatomy & histology / Q000502:physiology*; D038524:Diffusion Magnetic Resonance Imaging; D006801:Humans; D008297:Male; D009413:Nerve Fibers, Myelinated / Q000502:physiology*; D055815:Young Adult