Advanced

AJNR - American Journal of Neuroradiology

Published ahead of print on November 1, 2007
doi: 10.3174/ajnr.A0788

This Article Abstract Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Citation Map Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via CrossRef Citing Articles via Google Scholar Google Scholar Articles by Reich, D.S. Articles by Calabresi, P.A. Search for Related Content PubMed PubMed Citation Articles by Reich, D.S. Articles by Calabresi, P.A.

Corticospinal Tract Abnormalities Are Associated with Weakness in Multiple Sclerosis

D.S. Reich^a,b, K.M. Zackowski^a,c,e, E.M. Gordon-Lipkin^a, S.A. Smith^b,d, B.A. Chodkowski^d, G.R. Cutter^f and P.A. Calabresi^a

^a Department of Neurology, Johns Hopkins University, Baltimore, Md
^b Department of Radiology, Johns Hopkins University, Baltimore, Md
^c Department of Physical Medicine and Rehabilitation, Johns Hopkins University, Baltimore, Md
^d F.M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, Md
^e Department of Physical Medicine and Rehabilitation, Kennedy Krieger Institute, Baltimore, Md
^f Department of Biostatistics, School of Public Health, University of Alabama at Birmingham, Birmingham, Ala

View larger version (14K): [in this window] [in a new window]   Fig 1. A, Box plots showing the distribution of normalized ankle dorsiflexion strength across our population of individuals with MS (92 ankles). Ankle strengths are reported as z-scores, corrected for age, handedness, and sex. Red indicates RRMS; green, SPMS; purple, PPMS. For each box-and-whisker plot, the central line represents the median, the box represents the interquartile range, and the whiskers represent the fifth and ninety-fifth percentiles. The dotted horizontal line denotes the fifth percentile of healthy controls. B, Correlation between ankle dorsiflexion and hip flexion strength in the same individuals (87 ankles and hips). The best-fitting linear regression line is shown in red.

View larger version (17K): [in this window] [in a new window]   Fig 2. CST profiles depicting the average MR imaging index at each tract position for the stronger half (green) and weaker half (red) of our MS cohort. Strength assessment was based on ankle dorsiflexion power. The 6 segments of the CST are demarcated with vertical lines and abbreviated as follows: ME indicates medulla; PO, pons; MB, midbrain; IC, internal capsule; CR, corona radiata; SC, subcortical white matter. Error bars show 1 standard error of the mean in each tract subsegment. Each plot corresponds to a different MR imaging index, labeled as the following: MD; 1, 2, and 3 (the major, medium, and minor diffusion tensor eigenvalues); FA; T2 relaxation time; and MTR. Where there was a significant difference between median MR imaging indices for stronger and weaker subjects, the P value is given within the corresponding segment at the top of the plot. Significance was determined by multiple linear regression analysis, accounting for age, sex, and number of reconstructed fibers in the CST.

View larger version (62K): [in this window] [in a new window]   Fig 3. Sample axial sections from MD maps (left) and CST profiles (right) from 3 individuals with MS at 2 different time points (red, earlier; green, later). The mean (black) and 90% confidence intervals (gray), derived from a collection of healthy controls, are also displayed. The CST segments are abbreviated as follows: ME indicates medulla; PO, pons; MB, midbrain; IC, internal capsule; CR, corona radiata; SC, subcortical white matter. A, Left tract: A 33-year-old man with RRMS. B, Right tract: A 40-year-old woman with RRMS. C, Left tract: A 49-year-old man with SPMS.