Evaluation of myelin content in the spinal cord of patients with multiple sclerosis: A positron emission tomography study

Mult Scler Relat Disord. 2024 Dec 21:93:106248. doi: 10.1016/j.msard.2024.106248. Online ahead of print.

Abstract

Background: Multiple sclerosis (MS) is divided into Relapsing-Remitting (RRMS) and Progressive (PMS) phenotypes, both associated with spinal cord (SC) damage. MS-related disability and SC atrophy are not yet fully understood and can differ across phenotypes. A combined approach using Positron Emission Tomography (PET) and Magnetic Resonance Imaging (MRI) could provide a broader understanding of myelin changes in the cervical SC (CSC) in different MS phenotypes and the associations with disability.

Objectives: To evaluate CSC myelin content using a PET-MRI with [11C]PIB and its association with disability in PMS and RRMS compared to healthy volunteers (HV).

Methods: [11C]PIB PET images and T1-MRI of 49 patients with MS and 19 HV were evaluated at C1-C2, C3, and C4 vertebrae levels. [11C]PIB uptake and volume were compared between groups.

Results: [11C]PIB uptake was significantly lower at C1-C4, C1-C2, and C3 segments when comparing PMS to RRMS and HV. [11C]PIB uptake inversely correlated with overall disability in all CSC segments in all patients with MS, and in the RRMS phenotype separately.

Conclusions: Our findings suggest an association between [11C]PIB CSC uptake and overall disability score measured by EDSS. MRI and PET can be used as complementary methods for studying MS.

Keywords: MRI; Multiple sclerosis; Myelin content; PET; Spinal cord; [(11)C]PIB.