Spinal Cord MRI In Multiple Sclerosis

There is a need to assess Spinal Cord involvement in Multiple Sclerosis with new imaging techniques in order to understand better the underlying pathology.

We aimed to evaluate whether quantitative MRI measures, obtained using single-Voxel (1)H-MR Spectroscopy of the Cervical Cord.

And, Diffusion-based Tractography of the major Spinal Cord pathways, in patients with a Cervical Cord relapse, differed from controls and correlated with acute disability.

Fourteen patients at the onset of a Cervical Cord relapse with at least one lesion between C1 and C3 were imaged on a 1.5 T Scanner.

And, clinically assessed on the Expanded Disability Status Scale (EDSS), 9-Hole Peg Test (9-HPT) and Timed 25-Foot Walk Test.

Thirteen age- and gender-matched control subjects were also scanned.

Metabolite concentrations, including total N-AcetylAspartate (tNAA), Choline-containing compounds (Cho), Creatine plus PhosphoCreatine (Cr) and myo-Inositol (m-Ins), were quantified at C1-C3.

Probabilistic Tractography was performed at C1-C3 to track:
1. The Lateral Cortico-Spinal Tracts in the Lateral Columns
2. The Anterior Cortico-Spinal Tracts
3. The Anterior Spino-Thalamic Fasciculi in the Anterior Columns
4. The Bilateral Fasciculus Gracilis and Cuneatus in
   • The Posterior Columns

Diffusion- and Tractography-derived measures of these tracts, including Fractional Anisotropy and Voxel-based connectivity, which reflect fiber integrity, were obtained.

These MRI measures were compared between patients and controls using the Mann-Whitney test. Univariate correlations between MRI measures and disability were assessed using the Spearman's rho correlation coefficient.

Multiple regression analyses were performed to investigate which MRI measures independently correlated with the clinical scores, adjusting also for Cross-Sectional Cord Area, age and gender.

Patients showed lower tNAA of the Cervical Cord, lower connectivity and lower Fractional Anisotropy of the Lateral Cortico-Spinal Tracts and Posterior Tracts, than controls.

In patients, there were significant correlations between:
1. EDSS and m-Ins, Cho, Cr and radial Diffusivity of the Lateral Cortico-Spinal Tracts
2. HPT and Cr, radial Diffusivity of the Lateral Cortico-Spinal Tracts, connectivity and Fractional Anisotropy of the Posterior Tracts, and connectivity of the Anterior Tracts

M-Ins was independently associated with the EDSS, while Cr, tNAA and connectivity of the Posterior Tracts were independently associated with the 9-HPT.

MR Spectroscopy and Diffusion-based Tractography of the Cervical Cord provide measures that are sensitive to the tissue damage occurring in this area in patients with a Cervical Cord relapse.

These measures were found to correlate with acute disability.

Our findings suggest that it would be worthwhile performing longitudinal studies and extending these novel techniques to other Neurological Diseases affecting the Spinal Cord.

Purpose
To determine whether the Upper Cervical Cord Area (UCCA) is influenced by disease effect in early Relapsing/Remitting Multiple Sclerosis (MS), using statistical modeling to account for potential covariates.

Materials And Methods
A cohort of 39 patients were studied Cross-Sectionally within three years of first symptom onset (median disease duration = 1.6 years) and compared with 26 healthy controls.

The UCCA was measured from axial reconstructions of three-dimensional T₁-weighted scans with automated detection of the edge of the Cord.

Statistical analysis adjusted for factors such as Total IntraCranial Volume (TICV) and gender. Clinical correlations, in particular those thought likely to be related to Cord pathology, were also investigated.

Results
No significant disease effect was noted on UCCA (P = 0.685), although there was borderline evidence of a lower UCCA in patients with symptoms of Bowel or Bladder disturbance (P = 0.043).

A strong association was noted between UCCA and TICV (r = 0.558; P < or = 0.001), and there was a trend for females to have a smaller UCCA (P = 0.062).

The latter finding appeared to reflect a gender-related difference in TICV (P < or = 0.001).

Conclusion
Atrophy of the Upper Cervical Cord is not readily apparent in most patients early in the course of Relapsing/Remitting MS.

In evaluations of disease-related changes in the UCCA in Cross-Sectional studies, TICV and gender should be considered as potentially confounding covariates.

2006 Wiley-Liss, Inc.

Background And Purpose
While Brain MR imaging is routinely performed, the MR imaging assessment of Spinal Cord Pathology in Multiple Sclerosis (MS) is less frequent in clinical practice.

The purpose of this study was to determine whether measurements of Medulla Oblongata Volume (MOV) on routine Brain MR imaging could serve as a biomarker of Spinal Cord Damage and Disability in MS.

Materials And Methods
We identified 45 patients with MS with both head and Cervical Spinal Cord MR imaging and 29 age-matched and sex-matched healthy control subjects with head MR imaging.

Disability was assessed by the Expanded Disability Status Scale (EDSS) and Ambulation Index (AI). MOV and Upper Cervical Cord Volume (UCCV) were manually segmented; semiautomated segmentation was used for Brain Parenchymal Fraction (BPF).

These measures were compared between groups, and linear regression models were built to predict disability.

Results
In the patients, MOV correlated significantly with UCCV (r = 0.67), BPF (r = 0.45), disease duration (r = -0.64), age (r = -0.47), EDSS score (r = -0.49) and AI (r = -0.52).

Volume loss of the Medulla Oblongata was -0.008 cm(3)/year of age in patients with MS, but no significant linear relationship with age was found for healthy control subjects.

The patients had a smaller MOV (mean +/- SD, 1.02 +/- 0.17 cm(3)) than healthy control subjects (1.15 +/- 0.15 cm(3)), though BPF was unable to distinguish between these 2 groups.

MOV was smaller in patients with Progressive MS (Secondary/Progressive MS, 0.88 +/- 0.19 cm(3) and Primary/Progressive MS, 0.95 +/- 0.30 cm(3)) than in patients with Relapsing/Remitting MS (1.08 +/- 0.15 cm(3)).

A model including both MOV and BPF better predicted AI than BPF alone (P = .04). Good reproducibility in MOV measurements was demonstrated for intrarater (intraclass correlation coefficient, 0.97), interrater (0.79), and scan rescan data (0.81).

Conclusion
MOV is associated with disability in MS and can serve as a biomarker of Spinal Cord damage.