Related Experiment Video
Updated: Apr 5, 2026
Comprehensive Autopsy Program for Individuals with Multiple Sclerosis
Published on: July 19, 2019
A longitudinal study of cortical grey matter lesion subtypes in relapse-onset multiple sclerosis
Varun Sethi1, Tarek Yousry2, Nils Muhlert3
1NMR Research Unit, Department of Neuroinflammation, Queen Square MS Centre, UCL Institute of Neurology, London, UK.
Background:
Cortical grey matter (GM) lesions are common in multiple sclerosis (MS), but little is known about their temporal evolution. We investigated this in people with relapsing-remitting (RR) and secondary progressive (SP) MS.
Methods:
27 people with RRMS, and 22 with SPMS were included in this study. Phase-sensitive inversion recovery scans were acquired on 2 occasions. Cortical GM lesions were classified as intracortical (IC, only involving GM) and leucocortical (LC, mixed GM-white matter (WM)); WM lesions touching the cortex as juxtacortical (JC). On follow-up scans, new IC, LC and JC lesions were identified, and any change in classification of lesions previously observed was noted. WM lesion counts in the whole brain were assessed on PD/T2-weighted scans.
Results:
Over a mean (SD) of 21.0 (5.8) months, the number of new IC lesions per person per year was greater in SPMS (1.6 (1.9)) than RRMS (0.8 (1.9)) (Mann-Whitney p=0.039). All new LC lesions arose from previously seen IC lesions (SPMS 1.4 (1.8) per person per year, and RRMS 1.1 (1.0)), and none arose de novo, or from previously seen JC lesions. Changes in cortical GM (either new IC or IC converting to LC) lesion counts did not correlate with the changes in WM lesion counts.
Conclusions:
New cortical GM lesions rarely arise from the WM and the rate of new IC lesion formation is not closely linked with WM lesion accrual. IC lesion formation appears to be more common in SPMS than RRMS.
Insights
New intracortical (IC) lesions in multiple sclerosis (MS) are more common in secondary progressive MS (SPMS) than relapsing-remitting MS (RRMS). Cortical grey matter lesion formation is not closely linked to white matter lesion accrual.
Area of Science:
- Neuroscience
- Radiology
- Immunology
Background:
- Cortical grey matter (GM) lesions are a hallmark of multiple sclerosis (MS), yet their dynamic evolution remains poorly understood.
- This study focuses on characterizing the temporal changes of cortical GM lesions in different MS subtypes.
Purpose of the Study:
- To investigate the temporal evolution of cortical grey matter lesions in relapsing-remitting MS (RRMS) and secondary progressive MS (SPMS).
- To compare the incidence of new intracortical (IC) and leucocortical (LC) lesions between RRMS and SPMS patients.
- To assess the relationship between cortical GM lesion development and white matter (WM) lesion accumulation.
Main Methods:
- Inclusion of 27 RRMS and 22 SPMS patients.
- Acquisition of phase-sensitive inversion recovery MRI scans at two time points.
- Classification of lesions: intracortical (IC), leucocortical (LC), and juxtacortical (JC). Assessment of WM lesion counts on PD/T2-weighted scans.
Main Results:
- A higher rate of new IC lesions per person per year was observed in SPMS (1.6) compared to RRMS (0.8).
- All new LC lesions originated from pre-existing IC lesions, with no de novo LC lesions or those arising from JC lesions.
- Changes in cortical GM lesion counts did not correlate with changes in WM lesion counts.
Conclusions:
- New cortical GM lesions seldom originate from white matter, and their formation rate is not tightly coupled with WM lesion accrual.
- Intracortical lesion formation appears to be more prevalent in SPMS than in RRMS.
