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

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.