title: Age effects on diffusion tensor magnetic resonance imaging tractography measures of frontal cortex connections in schizophrenia.
abstract: Diffusion tensor magnetic resonance imaging (DT-MRI) has previously been used to investigate white matter tracts in schizophrenia, with inconsistent results. The aim of the study was to use a novel method for tract-specific measurements of fronto-temporal fasciculi in early-onset schizophrenia. We hypothesized that by making tract-specific measurements, clear diffusion abnormalities would be revealed in specific fasciculi in schizophrenia. Measurements of diffusion anisotropy and mean diffusivity were localized within fronto-temporal fasciculi by forming 3-D reconstructions of the cingulum, uncinate, superior longitudinal, and inferior fronto-occipital fasciculi using diffusion tensor tractography. We were limited in our ability to test our hypothesis by the important and surprising finding that age affected DT-MRI-based measures in schizophrenia patients in a different way from comparison subjects, most notably in the left superior longitudinal fasciculus. The youngest schizophrenia patients that we studied had lower diffusion anisotropy than age-matched comparison subjects, but this difference diminished with increasing age. The main conclusion of this study was that direct comparisons of absolute DT-MRI-based measures between individuals with schizophrenia and comparison subjects may be problematic and misleading because of underlying age-related differences in brain maturation between groups.
authors.affiliation: Section on Tissue Biophysics and Biomimetics, LIMB, NICHD, National Institutes of Health, Bethesda, Maryland, USA.
authors.forename: Derek K
authors.initials: DK
authors.lastname: Jones
authors.forename: Marco
authors.initials: M
authors.lastname: Catani
authors.forename: Carlo
authors.initials: C
authors.lastname: Pierpaoli
authors.forename: Suzanne J C
authors.initials: SJ
authors.lastname: Reeves
authors.forename: Sukhwinder S
authors.initials: SS
authors.lastname: Shergill
authors.forename: Michael
authors.initials: M
authors.lastname: O'Sullivan
authors.forename: Pasha
authors.initials: P
authors.lastname: Golesworthy
authors.forename: Phillip
authors.initials: P
authors.lastname: McGuire
authors.forename: Mark A
authors.initials: MA
authors.lastname: Horsfield
authors.forename: Andrew
authors.initials: A
authors.lastname: Simmons
authors.forename: Steven C R
authors.initials: SC
authors.lastname: Williams
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Howard
mesh_terms: D000328:Adult; D000367:Age Factors; D000375:Aging / Q000502:physiology; D016880:Anisotropy; D001931:Brain Mapping / Q000379:methods*; D002540:Cerebral Cortex / Q000473:pathology* / Q000503:physiopathology; D004058:Diffusion; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009413:Nerve Fibers, Myelinated / Q000473:pathology* / Q000502:physiology; D009434:Neural Pathways / Q000473:pathology*; D012559:Schizophrenia / Q000175:diagnosis* / Q000503:physiopathology