Cortical lesion load correlates with diffuse injury of multiple sclerosis normal appearing white matter

2013 ◽  
Vol 20 (2) ◽  
pp. 227-233 ◽  
Author(s):  
Niraj Mistry ◽  
Rasha Abdel-Fahim ◽  
Olivier Mougin ◽  
Christopher Tench ◽  
Penny Gowland ◽  
...  

Background:Degeneration of central nervous system normal appearing white matter (NAWM) underlies disability and progression in multiple sclerosis (MS). Axon loss typifies NAWM degeneration.Objective:The objective of this paper is to assess correlation between cortical lesion load and magnetisation transfer ratio (MTR) of the NAWM in MS. This was in order to test the hypothesis that cortical lesions cause NAWM degeneration.Methods:Nineteen patients with MS underwent 7 Tesla magnetisation-prepared-rapid-acquisition-gradient-echo (MPRAGE), and magnetisation transfer ratio (MTR) brain magnetic resonance imaging (MRI). Cortical lesions were identified using MPRAGE and MTR images of cortical ribbons. White matter lesions (WMLs) were segmented using MPRAGE images. WML maps were subtracted from white matter volumes to produce NAWM masks. Pearson correlation was calculated for NAWM MTR vs cortical lesion load, and WML volumes.Results:Cortical lesion volumes and counts all had significant correlation with NAWM mean MTR. The strongest correlation was with cortical lesion volumes obtained using MTR images ( r = −0.6874, p = 0.0006). WML volume had no significant correlation with NAWM mean MTR ( r = −0.08706, p = 0.3615).Conclusion:Our findings are consistent with the hypothesis that cortical lesions cause NAWM degeneration. This implicates cortical lesions in the pathogenesis of NAWM axon loss, which underpins long-term disability and progression in MS.

2019 ◽  
Vol 26 (6) ◽  
pp. 679-687 ◽  
Author(s):  
James William L Brown ◽  
Azmain Chowdhury ◽  
Baris Kanber ◽  
Ferran Prados Carrasco ◽  
Arman Eshaghi ◽  
...  

Background: In relapse-onset multiple sclerosis (MS), tissue abnormality – as assessed with magnetisation transfer ratio (MTR) imaging – is greater in the outer cortical and inner periventricular layers. The cause of this remains unknown but meningeal inflammation has been implicated, particularly lymphoid follicles, which are seen in secondary progressive (SP) but not primary progressive (PP) MS. Cortical and periventricular MTR gradients might, therefore, differ in PPMS and SPMS if these follicles are responsible. Objective: We assessed cortical and periventricular MTR gradients in PPMS, and compared gradients between people with PPMS and SPMS. Methods: Using an optimised processing pipeline, periventricular normal-appearing white matter and cortical grey-matter MTR gradients were compared between 51 healthy controls and 63 people with progressive MS (28 PPMS, 35 SPMS). Results: The periventricular gradient was significantly shallower in healthy controls (0.122 percentage units (pu)/band) compared to PPMS (0.952 pu/band, p < 0.0001) and SPMS (1.360 pu/band, p < 0.0001). The cortical gradient was also significantly shallower in healthy controls (−2.860 pu/band) compared to PPMS (−3.214 pu/band, p = 0.038) and SPMS (−3.328 pu/band, p = 0.016). Conclusion: Abnormal periventricular and cortical MTR gradients occur in both PPMS and SPMS, suggesting comparable underlying pathological processes.


2019 ◽  
Vol 26 (9) ◽  
pp. 1093-1101
Author(s):  
J William L Brown ◽  
Ferran Prados Carrasco ◽  
Arman Eshaghi ◽  
Carole H Sudre ◽  
Tom Button ◽  
...  

Background: In multiple sclerosis (MS), disease effects on magnetisation transfer ratio (MTR) increase towards the ventricles. This periventricular gradient is evident shortly after first symptoms and is independent of white matter lesions. Objective: To explore if alemtuzumab, a peripherally acting disease-modifying treatment, modifies the gradient’s evolution, and whether baseline gradients predict on-treatment relapses. Methods: Thirty-four people with relapsing-remitting MS underwent annual magnetic resonance imaging (MRI) scanning (19 receiving alemtuzumab (four scans each), 15 untreated (three scans each)). The normal-appearing white matter was segmented into concentric bands. Gradients were measured over the three bands nearest the ventricles. Mixed-effects models adjusted for age, gender, relapse rate, lesion number and brain parenchymal fraction compared the groups’ baseline gradients and evolution. Results: Untreated, the mean MTR gradient increased (+0.030 pu/band/year) but decreased following alemtuzumab (−0.045 pu/band/year, p = 0.037). Within the alemtuzumab group, there were no significant differences in baseline lesion number ( p = 0.568) nor brain parenchymal fraction ( p = 0.187) between those who relapsed within 4 years ( n = 4) and those who did not ( n = 15). However, the baseline gradient was significantly different ( p = 0.020). Conclusion: Untreated, abnormal periventricular gradients worsen with time, but appear reversible with peripheral immunotherapy. Baseline gradients – but not lesion loads or brain volumes – may predict on-treatment relapses. Larger confirmatory studies are required.


2014 ◽  
Vol 20 (10) ◽  
pp. 1322-1330 ◽  
Author(s):  
Rebecca S Samson ◽  
Manuel J Cardoso ◽  
Nils Muhlert ◽  
Varun Sethi ◽  
Claudia AM Wheeler-Kingshott ◽  
...  

Background: Pathological abnormalities including demyelination and neuronal loss are reported in the outer cortex in multiple sclerosis (MS). Objective: We investigated for in vivo evidence of outer cortical abnormalities by measuring the magnetisation transfer ratio (MTR) in MS patients of different subgroups. Methods: Forty-four relapsing–remitting (RR) (mean age 41.9 years, median Expanded Disability Status Scale (EDSS) 2.0), 25 secondary progressive (SP) (54.1 years, EDSS 6.5) and 19 primary progressive (PP) (53.1 years, EDSS 6.0) MS patients and 35 healthy control subjects (mean age 39.2 years) were studied. Three-dimensional (3D) 1×1×1mm3 T1-weighted images and MTR data were acquired. The cortex was segmented, then subdivided into outer and inner bands, and MTR values were calculated for each band. Results: In a pairwise analysis, mean outer cortical MTR was lower than mean inner cortical MTR in all MS groups and controls ( p<0.001). Compared with controls, outer cortical MTR was decreased in SPMS ( p<0.001) and RRMS ( p<0.01), but not PPMS. Outer cortical MTR was lower in SPMS than PPMS ( p<0.01) and RRMS ( p<0.01). Conclusions: Lower outer than inner cortical MTR in healthy controls may reflect differences in myelin content. The lowest outer cortical MTR was seen in SPMS and is consistent with more extensive outer cortical (including subpial) pathology, such as demyelination and neuronal loss, as observed in post-mortem studies of SPMS patients.


2004 ◽  
Vol 10 (2) ◽  
pp. 188-196 ◽  
Author(s):  
Emmanuelle Cassol ◽  
Jean-Philippe Ranjeva ◽  
Danielle Ibarrola ◽  
Claude Mékies ◽  
Claude Manelfe ◽  
...  

Our objectives were to determine the reproducibility of diffusion tensor imaging (DTI) in volunteers and to evaluate the ability of the method to monitor longitudinal changes occurring in the normal-appearing white matter (NAWM) of patients with multiple sclerosis (MS). DTI was performed three-mo nthly for one year in seven MS patients: three relapsing-remitting (RRMS), three secondary progressive (SPMS) and one relapsing SP. They were selected with a limited cerebral lesion load. Seven age- and sex-matched controls also underwent monthly examinations for three months. Diffusivity and anisotropy were quantified over the segmented whole supratentorial white matter, with the indices of trace (Tr) and fractional anisotropy (FA). Results obtained in volunteers show the reproducibility of the method. Patients had higher trace and lower anisotropy than matched controls (P B-0.0001). O ver the follow-up, both Tr and FA indicated a recovery after the acute phase in RRMS and a progressive shift towards abnormal values in SPMS. A lthough this result is not statistically significant, it suggests that DTI is sensitive to microscopic changes occurring in tissue of normal appearance in conventional images and could be useful for monitoring the course of the disease, even though it was unable to clearly distinguish between the various physiopathological processes involved.


1999 ◽  
Vol 5 (5) ◽  
pp. 313-316 ◽  
Author(s):  
S M Leary ◽  
N C Silver ◽  
V L Stevenson ◽  
G J Barker ◽  
D H Miller ◽  
...  

Patients with primary progressive multiple sclerosis may develop severe disability despite a paucity of lesions on conventional magnetic resonance imaging, raising the possibility that intrinsic changes in normal appearing white matter (NAWM) contribute to disability. This study has measured magnetisation transfer ratio (MTR), an index of tissue damage, of NAWM in 52 patients with primary progressive multiple sclerosis and 26 healthy controls. Absolute values of MTR were obtained from the genu of the corpus callosum and pons, and mean values were calculated from bilateral regions in the centrum semiovale, frontal white matter, parieto-occipital white matter and posterior limb of the internal capsule. The median MTR was lower in all regions in patients compared to controls. Median values (per cent units) were significantly lower in corpus callosum (39.73 vs 40.63; P=0.01), frontal white matter (39.11 vs 39.59; P=0.01) and centrum semiovale (37.21 vs 37.82; P50.05). This study has demonstrated small but widespread decreases in MTR in NAWM in primary progressive multiple sclerosis supporting the hypothesis that there are intrinsic changes in NAWM which may contribute to disability in this patient group.


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