Longitudinal clinical study of patients with iron rim lesions in multiple sclerosis

Mult Scler. 2022 Dec;28(14):2202-2211. doi: 10.1177/13524585221114750. Epub 2022 Aug 24.

Abstract

Background: Iron rims (IRs) surrounding white matter lesions (WMLs) are suggested to predict a more severe disease course. Only small longitudinal cohorts of patients with and without iron rim lesions (IRLs) have been reported so far.

Objective: To assess whether the presence and number of IRLs in patients with clinically isolated syndrome (CIS) and multiple sclerosis (MS) are associated with long-term disability or progressive disease.

Methods: Ninety-one CIS/MS patients were recruited between 2008 and 2013 and scanned with 7 T magnetic resonance imaging (MRI). Expanded Disability Status Scale (EDSS) was used to calculate Age-related Multiple Sclerosis Severity Score (ARMSS) at the time of scan and at the latest clinical follow-up after 9 years. WMLs were assessed for the presence of IRL using Susceptibility weighted imaging (SWI)-filtered phase images.

Results: In all, 132 IRLs were detected in 42 patients (46%); 9% of WMLs had IRs; 54% of the cohort had no rims, 30% had 1-3 rims and 16% had ⩾4. Patients with IRL had a higher EDSS and ARMSS. Presence of IRL was also a predictor of long-term disability, especially in patients with ⩾4 IRLs. IRLs have a greater impact on disability compared to the WML number and volume.

Conclusion: The presence and number of perilesional IR on MRI hold prognostic value for long-term clinical disability in MS.

Keywords: Multiple sclerosis (MS); biomarkers; iron rim lesion (IRL); magnetic resonance imaging (MRI); white matter lesion (WML).

MeSH terms

  • Child
  • Demyelinating Diseases* / diagnostic imaging
  • Disease Progression
  • Humans
  • Iron
  • Longitudinal Studies
  • Multiple Sclerosis* / diagnostic imaging

Substances

  • Iron