title: TI-relaxation time changes over five years in relapsing-remitting multiple sclerosis.
abstract: The pathological effects of multiple sclerosis are not confined to lesions; tissues that appear normal on conventional magnetic resonance imaging scans are also affected, albeit subtly. One imaging technique that has proven sensitive to such effects is T1-relaxation time measurement, with previous work demonstrating abnormalities in normal-appearing white matter and grey matter. In this work we investigated the evolution of T1-relaxation time changes in normal-appearing white matter and grey matter in relapsing-remitting multiple sclerosis. Three- and five-year follow-up data from 35 people with clinically early (a mean of 1.6 years from first clinical event) relapsing-remitting multiple sclerosis and 15 healthy controls were analysed. T1-relaxation time histograms were extracted from normal-appearing white matter and grey matter, and mean, peak height and peak location values were estimated. T1-relaxation time peak height declined in the multiple sclerosis normal-appearing white matter and grey matter, but not the control group (rate difference p = 0.024 in normal-appearing white matter, in normal-appearing grey matter p = 0.038); other T1-relaxation time changes were not significantly different between groups. Changes in T1-relaxation time measures did not correlate with increases in brain T2-weighted lesion loads or Expanded Disability Status Scale scores. These results suggest that the processes underlying changes in normal-appearing white matter and grey matter T1-relaxation times are not immediately linked to white matter lesion formation, and may represent more diffuse but progressive sub-clinical pathology in relapsing-remitting multiple sclerosis.
authors.affiliation: B Neurological Clinic, AHEPA University Hospital, Aristotle University of Thessaloniki, Greece.
authors.forename: Konstantinos
authors.initials: K
authors.lastname: Papadopoulos
authors.forename: Daniel J
authors.initials: DJ
authors.lastname: Tozer
authors.forename: Leonora
authors.initials: L
authors.lastname: Fisniku
authors.forename: Daniel R
authors.initials: DR
authors.lastname: Altmann
authors.forename: Gerard
authors.initials: G
authors.lastname: Davies
authors.forename: Waqar
authors.initials: W
authors.lastname: Rashid
authors.forename: Alan J
authors.initials: AJ
authors.lastname: Thompson
authors.forename: David H
authors.initials: DH
authors.lastname: Miller
authors.forename: Declan T
authors.initials: DT
authors.lastname: Chard
mesh_terms: D000328:Adult; D001921:Brain / Q000473:pathology*; D016022:Case-Control Studies; D004185:Disability Evaluation; D018450:Disease Progression; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D016014:Linear Models; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D020529:Multiple Sclerosis, Relapsing-Remitting / Q000175:diagnosis*; D011237:Predictive Value of Tests; D013997:Time Factors