Contributions
Abstract: P804
Type: Poster Sessions
Abstract Category: Pathology and pathogenesis of MS - MRI and PET
Introduction: Radiologically isolated syndrome (RIS) describes asymptomatic individuals with incidental radiologic abnormalities highly suggestive of multiple sclerosis (MS). Recent susceptibility-based MRI studies demonstrate that a significant proportion of white matter lesions (WML) in MS patients have visible central veins (“central vein sign” (CVS)), which can assist in differentiating MS from other white matter disorders. Furthermore, a subgroup of chronic MS lesions can demonstrate an increase in magnetic susceptibility along the lesion rim on phase images (“paramagnetic rim sign” (PRS)), which may represent chronic, active inflammation (attributed to paramagnetic effects from iron-laden microglia/macrophages at the lesion edge). To date, the CVS and PRS have not yet been assessed in RIS.
Objective: To assess for the presence of the CVS and PRS in WMLs of RIS.
Methods: 15 individuals with RIS, diagnosed according to Okuda criteria, underwent 3.0T MRI to obtain 3D-FLAIR and 3D-T2* EPI. The CVS and PRS were assessed in WMLs on T2* magnitude and phase images, respectively.
Results: All of the RIS cases recruited in this study had WMLs positive for the central vein sign (CVS+). The mean proportion of CVS+ WMLs per case was 83% (range:31-100%). 14 (93%) had central veins in >40% of WML, meeting one proposed threshold to distinguish MS from other disorders. The PRS was present in 11 cases (73%), and the mean proportion of WMLs positive for the paramagnetic rim sign (PRS+) per case was 19% (range:8-44%). PRS were absent in 4 RIS cases (27%): 3 had low total lesion loads (9-25 WMLs), and 1 had the lowest proportion of CVS+ WML (31%). There were strong correlations between proportions of CVS+ WML and PRS+ WML (rho=0.86, p< 0.001).
Conclusions: In our sample, most RIS cases had a large proportion of CVS+ WMLs, indicating perivenular pathology. Furthermore, a large (though smaller) proportion also had PRS+ WMLs. RIS cases without PRS had low WML load and/or low proportions of CVS+ WML. These findings suggest that the majority of RIS subjects harbor subclinical chronic active demyelination and may be at risk of eventually developing progressive clinical symptoms. Both CVS and PRS could potentially be useful to differentiate true RIS (i.e. subclinical inflammatory demyelination) from mimickers. Prospective follow-up of this cohort is planned, which will enable a better understanding of the differential diagnostic and predictive value of the CVS and PRS in RIS.
Disclosure: Suradech Suthiphosuwan, MD, FRCR: Dr. Suthiphosuwan has received fellowship funding support through an educational grant from Sanofi-Genzyme.
Pascal Sati, PhD: Nothing to disclose
Melanie Guenette, MSc: Nothing to disclose
Martina Absinta, MD, PhD: Dr. Absinta is supported by the Intramural Research Program of NINDS, by the Conrad N. Hilton Foundation (grant #EIN 15-20858115) and by the National Multiple Sclerosis Society (NMSS) (grant #FG 2093-A-1).
Daniel S. Reich, MD, PhD: Nothing to disclose
Aditya Bharatha, MD, FRCPC: Nothing to disclose
Jiwon Oh, MD, FRCPC, PhD: Dr. Jiwon Oh has received research grant funding from the MS Society of Canada, National MS Society, Brain Canada, Biogen-Idec, and Sanofi-Genzyme. Dr. Oh has also received personal compensation for consulting or speaking from EMD-Serono, Sanofi-Genzyme, Biogen-Idec, Novartis, and Roche.
Abstract: P804
Type: Poster Sessions
Abstract Category: Pathology and pathogenesis of MS - MRI and PET
Introduction: Radiologically isolated syndrome (RIS) describes asymptomatic individuals with incidental radiologic abnormalities highly suggestive of multiple sclerosis (MS). Recent susceptibility-based MRI studies demonstrate that a significant proportion of white matter lesions (WML) in MS patients have visible central veins (“central vein sign” (CVS)), which can assist in differentiating MS from other white matter disorders. Furthermore, a subgroup of chronic MS lesions can demonstrate an increase in magnetic susceptibility along the lesion rim on phase images (“paramagnetic rim sign” (PRS)), which may represent chronic, active inflammation (attributed to paramagnetic effects from iron-laden microglia/macrophages at the lesion edge). To date, the CVS and PRS have not yet been assessed in RIS.
Objective: To assess for the presence of the CVS and PRS in WMLs of RIS.
Methods: 15 individuals with RIS, diagnosed according to Okuda criteria, underwent 3.0T MRI to obtain 3D-FLAIR and 3D-T2* EPI. The CVS and PRS were assessed in WMLs on T2* magnitude and phase images, respectively.
Results: All of the RIS cases recruited in this study had WMLs positive for the central vein sign (CVS+). The mean proportion of CVS+ WMLs per case was 83% (range:31-100%). 14 (93%) had central veins in >40% of WML, meeting one proposed threshold to distinguish MS from other disorders. The PRS was present in 11 cases (73%), and the mean proportion of WMLs positive for the paramagnetic rim sign (PRS+) per case was 19% (range:8-44%). PRS were absent in 4 RIS cases (27%): 3 had low total lesion loads (9-25 WMLs), and 1 had the lowest proportion of CVS+ WML (31%). There were strong correlations between proportions of CVS+ WML and PRS+ WML (rho=0.86, p< 0.001).
Conclusions: In our sample, most RIS cases had a large proportion of CVS+ WMLs, indicating perivenular pathology. Furthermore, a large (though smaller) proportion also had PRS+ WMLs. RIS cases without PRS had low WML load and/or low proportions of CVS+ WML. These findings suggest that the majority of RIS subjects harbor subclinical chronic active demyelination and may be at risk of eventually developing progressive clinical symptoms. Both CVS and PRS could potentially be useful to differentiate true RIS (i.e. subclinical inflammatory demyelination) from mimickers. Prospective follow-up of this cohort is planned, which will enable a better understanding of the differential diagnostic and predictive value of the CVS and PRS in RIS.
Disclosure: Suradech Suthiphosuwan, MD, FRCR: Dr. Suthiphosuwan has received fellowship funding support through an educational grant from Sanofi-Genzyme.
Pascal Sati, PhD: Nothing to disclose
Melanie Guenette, MSc: Nothing to disclose
Martina Absinta, MD, PhD: Dr. Absinta is supported by the Intramural Research Program of NINDS, by the Conrad N. Hilton Foundation (grant #EIN 15-20858115) and by the National Multiple Sclerosis Society (NMSS) (grant #FG 2093-A-1).
Daniel S. Reich, MD, PhD: Nothing to disclose
Aditya Bharatha, MD, FRCPC: Nothing to disclose
Jiwon Oh, MD, FRCPC, PhD: Dr. Jiwon Oh has received research grant funding from the MS Society of Canada, National MS Society, Brain Canada, Biogen-Idec, and Sanofi-Genzyme. Dr. Oh has also received personal compensation for consulting or speaking from EMD-Serono, Sanofi-Genzyme, Biogen-Idec, Novartis, and Roche.