Marjan E Steenweg1, Nicole I Wolf1, Wessel N van Wieringen1, Frederik Barkhof1, Marjo S van der Knaap1, Petra J W Pouwels2. 1. From the Department of Child Neurology (M.E.S., N.I.W., M.S.v.d.K.), VU University Medical Center, and Neuroscience Campus Amsterdam; Department of Clinical Epidemiology and Biostatistics (W.N.v.W.), VU University Medical Center; Department of Mathematics (W.N.v.W.), and Department of Functional Genomics, Center for Neurogenomics and Cognitive Research (M.S.v.d.K., P.J.W.P.), VU University, Amsterdam; and Departments of Radiology (F.B.) and Physics and Medical Technology (P.J.W.P.), VU University Medical Center, Amsterdam, the Netherlands. 2. From the Department of Child Neurology (M.E.S., N.I.W., M.S.v.d.K.), VU University Medical Center, and Neuroscience Campus Amsterdam; Department of Clinical Epidemiology and Biostatistics (W.N.v.W.), VU University Medical Center; Department of Mathematics (W.N.v.W.), and Department of Functional Genomics, Center for Neurogenomics and Cognitive Research (M.S.v.d.K., P.J.W.P.), VU University, Amsterdam; and Departments of Radiology (F.B.) and Physics and Medical Technology (P.J.W.P.), VU University Medical Center, Amsterdam, the Netherlands. pjw.pouwels@vumc.nl.
Abstract
OBJECTIVE: To assess the correlation of tissue parameters estimated by quantitative magnetic resonance (MR) techniques and motor handicap in patients with hypomyelination. METHODS: Twenty-eight patients with different causes of hypomyelination (12 males, 16 females; mean age 10 years) and 61 controls (33 males, 28 females; mean age 8 years) were prospectively investigated. We quantified T2 relaxation time, magnetization transfer ratio, fractional anisotropy, mean, axial, and radial diffusivities, and brain metabolites. We performed measurements in the splenium, parietal deep white matter, and corticospinal tracts in the centrum semiovale. We further analyzed diffusion measures using tract-based spatial statistics. We estimated severity of motor handicap by the gross motor function classification system. We evaluated correlation of handicap with MR measures by linear regression analyses. RESULTS: Fractional anisotropy, magnetization transfer ratio, choline, and N-acetylaspartate/creatine ratio were lower and diffusivities, T2 values, and inositol were higher in patients than in controls. Tract-based spatial statistics showed that these changes were widespread for fractional anisotropy (96% of the white matter skeleton), radial (93%) and mean (84%) diffusivity, and less so for axial diffusivity (20%). Correlation with handicap yielded radial diffusivity and N-acetylaspartate/creatine ratio as strongest independent explanatory variables. CONCLUSIONS: Gross motor function classification system grades are in part explained by MR measures. They indicate that mainly lack of myelin and, to a lesser degree, loss of axonal integrity codetermine the degree of motor handicap in patients with hypomyelinating disorders. These MR measures can be used to evaluate strategies that are aimed at promotion of myelination.
OBJECTIVE: To assess the correlation of tissue parameters estimated by quantitative magnetic resonance (MR) techniques and motor handicap in patients with hypomyelination. METHODS: Twenty-eight patients with different causes of hypomyelination (12 males, 16 females; mean age 10 years) and 61 controls (33 males, 28 females; mean age 8 years) were prospectively investigated. We quantified T2 relaxation time, magnetization transfer ratio, fractional anisotropy, mean, axial, and radial diffusivities, and brain metabolites. We performed measurements in the splenium, parietal deep white matter, and corticospinal tracts in the centrum semiovale. We further analyzed diffusion measures using tract-based spatial statistics. We estimated severity of motor handicap by the gross motor function classification system. We evaluated correlation of handicap with MR measures by linear regression analyses. RESULTS: Fractional anisotropy, magnetization transfer ratio, choline, and N-acetylaspartate/creatine ratio were lower and diffusivities, T2 values, and inositol were higher in patients than in controls. Tract-based spatial statistics showed that these changes were widespread for fractional anisotropy (96% of the white matter skeleton), radial (93%) and mean (84%) diffusivity, and less so for axial diffusivity (20%). Correlation with handicap yielded radial diffusivity and N-acetylaspartate/creatine ratio as strongest independent explanatory variables. CONCLUSIONS: Gross motor function classification system grades are in part explained by MR measures. They indicate that mainly lack of myelin and, to a lesser degree, loss of axonal integrity codetermine the degree of motor handicap in patients with hypomyelinating disorders. These MR measures can be used to evaluate strategies that are aimed at promotion of myelination.
Authors: Yunus Msayib; George W J Harston; Kevin J Ray; James R Larkin; Brad A Sutherland; Fintan Sheerin; Nicholas P Blockley; Thomas W Okell; Peter Jezzard; Andrew Baldwin; Nicola R Sibson; James Kennedy; Michael A Chappell Journal: Magn Reson Med Date: 2022-03-07 Impact factor: 3.737
Authors: Diane F van Rappard; Marsh Königs; Marjan E Steenweg; Jaap Jan Boelens; Jaap Oosterlaan; Marjo S van der Knaap; Nicole I Wolf; Petra J W Pouwels Journal: J Neurol Date: 2018-01-30 Impact factor: 4.849