In vivo characterization of cortical lesion demyelination and remyelination in early multiple sclerosis by quantitative 7 Tesla MRI
ECTRIMS Online Library. Barletta V. 09/13/19; 279568; 310
Valeria Barletta
Valeria Barletta
Contributions
Abstract

Abstract: 310

Type: Scientific Session

Abstract Category: Pathology and pathogenesis of MS - MRI and PET

V. Barletta1,2, E. Herranz1,2, A. Treaba1,2, A. Mehndiratta2, R. Ouellette2, G. Mangeat3, J. Sloane1,4, N. Mercaldo2, J. Cohen-Adad3, C. Mainero1,2

1Harvard Medical School, 2Massachusetts General Hospital, Boston, MA, United States, 3Institute of Biomedical Engineering, Polytechnique Montreal, Montreal, QC, Canada, 4Beth Israel Deaconess Medical Center, Department of Neurology, Boston, MA, United States

Introduction. Cortical lesions (CL) appear early in multiple sclerosis (MS) and play a major role in disease progression. Ex vivo studies show that the cortex has an endogenous propensity for remyelination in MS. The Combined Myelin Estimation (CME) model from 7 Tesla (7T) quantitative T2* and T1 maps shows high sensitivity to intracortical MS pathology, likely related to myelin content changes.
Objectives. To assess and characterize in vivo, in early MS, the presence and evolution of myelination status in focal CL and across the whole cortex using the CME.
Methods. In 24 MS patients (disease duration< 5 years) and 17 healthy controls (HC) CME (0.5 mm3 isotropic) was estimated at 25%, 50% and 75% depth from pial surface by spatial independent component analysis to extract the shared myelin-related signal in 7T T1 and T2* maps. T2* and CME values were extracted from CL and normal appearing cortex (NAC) at 50% cortical depth. A general linear model (GLM) compared CME in MS versus HC along the cortex at the 3 depths. The relative difference in CME at 50% depth between MS and HC was used to classify CL as demyelinated or non-demyelinated. An increase or decrease by 1.96 SD of basal CME within CL was interpreted respectively as remyelination or demyelination at follow up. Linear regression models were used to compare CME and T2* in MS and HC. Paired t-test compared CME and T2* in CL and NAC.
Results. The GLM showed in MS widespread areas of reduced CME at all 3 depths relative to HC (p< 0.05), suggesting demyelination. CL were found in 19/24 (79%) patients. Overall, mean T2* was higher in CL compared to NAC (p=0.01) and HC cortex (p=0.01). Mean CME in CL was reduced with a trend for significance compared to NAC (p=0.07) and HC cortex (p=0.08). Cumulative number of CL was 98, of which 47 (48%) showed decreased CME values.
CL were present in 7/8 patients re-scanned after 1 year. Cumulative CL number was 54. At follow-up further CL demyelination was found in 5/7 patients within 17/54 CL (17% of total CL), remyelination was found only in one subject within 2/54 lesions (2% of total CL), 35/54 stable CL (65%) were found among all subjects. Demyelination status at baseline was a predictor of further CL demyelination at follow-up (p< 0.01).
Conclusions. CME discloses early diffuse cortical demyelination in MS and a heterogeneous myelin pattern within CL, which may be due to concomitant demyelination, incomplete demyelination and partial remyelination.
Disclosure: Barletta V: nothing to disclose. Herranz E has received research support by the NMSS fellowship FG150705459. Treaba A: nothing to disclose. Mehndiratta A: nothing to disclose. Ouellette R: nothing to disclose. Mangeat G: nothing to disclose. Sloane J: nothing to disclose. Mercaldo N: nothing to disclose. Cohen-Adad J: nothing to disclose. Mainero C: nothing to disclose. This study was supported by the National Institute of Health (NIH R01NS07832201 A1) and the National Multiple Sclerosis Society (NMSS grant RG-1802-30468).

Abstract: 310

Type: Scientific Session

Abstract Category: Pathology and pathogenesis of MS - MRI and PET

V. Barletta1,2, E. Herranz1,2, A. Treaba1,2, A. Mehndiratta2, R. Ouellette2, G. Mangeat3, J. Sloane1,4, N. Mercaldo2, J. Cohen-Adad3, C. Mainero1,2

1Harvard Medical School, 2Massachusetts General Hospital, Boston, MA, United States, 3Institute of Biomedical Engineering, Polytechnique Montreal, Montreal, QC, Canada, 4Beth Israel Deaconess Medical Center, Department of Neurology, Boston, MA, United States

Introduction. Cortical lesions (CL) appear early in multiple sclerosis (MS) and play a major role in disease progression. Ex vivo studies show that the cortex has an endogenous propensity for remyelination in MS. The Combined Myelin Estimation (CME) model from 7 Tesla (7T) quantitative T2* and T1 maps shows high sensitivity to intracortical MS pathology, likely related to myelin content changes.
Objectives. To assess and characterize in vivo, in early MS, the presence and evolution of myelination status in focal CL and across the whole cortex using the CME.
Methods. In 24 MS patients (disease duration< 5 years) and 17 healthy controls (HC) CME (0.5 mm3 isotropic) was estimated at 25%, 50% and 75% depth from pial surface by spatial independent component analysis to extract the shared myelin-related signal in 7T T1 and T2* maps. T2* and CME values were extracted from CL and normal appearing cortex (NAC) at 50% cortical depth. A general linear model (GLM) compared CME in MS versus HC along the cortex at the 3 depths. The relative difference in CME at 50% depth between MS and HC was used to classify CL as demyelinated or non-demyelinated. An increase or decrease by 1.96 SD of basal CME within CL was interpreted respectively as remyelination or demyelination at follow up. Linear regression models were used to compare CME and T2* in MS and HC. Paired t-test compared CME and T2* in CL and NAC.
Results. The GLM showed in MS widespread areas of reduced CME at all 3 depths relative to HC (p< 0.05), suggesting demyelination. CL were found in 19/24 (79%) patients. Overall, mean T2* was higher in CL compared to NAC (p=0.01) and HC cortex (p=0.01). Mean CME in CL was reduced with a trend for significance compared to NAC (p=0.07) and HC cortex (p=0.08). Cumulative number of CL was 98, of which 47 (48%) showed decreased CME values.
CL were present in 7/8 patients re-scanned after 1 year. Cumulative CL number was 54. At follow-up further CL demyelination was found in 5/7 patients within 17/54 CL (17% of total CL), remyelination was found only in one subject within 2/54 lesions (2% of total CL), 35/54 stable CL (65%) were found among all subjects. Demyelination status at baseline was a predictor of further CL demyelination at follow-up (p< 0.01).
Conclusions. CME discloses early diffuse cortical demyelination in MS and a heterogeneous myelin pattern within CL, which may be due to concomitant demyelination, incomplete demyelination and partial remyelination.
Disclosure: Barletta V: nothing to disclose. Herranz E has received research support by the NMSS fellowship FG150705459. Treaba A: nothing to disclose. Mehndiratta A: nothing to disclose. Ouellette R: nothing to disclose. Mangeat G: nothing to disclose. Sloane J: nothing to disclose. Mercaldo N: nothing to disclose. Cohen-Adad J: nothing to disclose. Mainero C: nothing to disclose. This study was supported by the National Institute of Health (NIH R01NS07832201 A1) and the National Multiple Sclerosis Society (NMSS grant RG-1802-30468).

By clicking “Accept Terms & all Cookies” or by continuing to browse, you agree to the storing of third-party cookies on your device to enhance your user experience and agree to the user terms and conditions of this learning management system (LMS).

Cookie Settings
Accept Terms & all Cookies