q-Space Myelin Map: A new myelin-specific imaging technique for treatment monitoring of multiple sclerosis

Abstract

Abstract Background The hallmark of multiple sclerosis (MS) is demyelination of the central nervous system. In the McDonald diagnostic criteria, hyperintense signals on T2-weighted image (so-called “T2-lesions”) by magnetic resonance imaging (MRI) can substitute for clinical findings as evidence of disease activities; however, T2 signals are theoretically non-specific for demyelination and its over-reliance may lead not only to misdiagnosis but also to the failure of accurately monitoring disease activities, hence potentially causing over or under-treatment. In order to provide a more myelin-specific modality, we have recently developed q-space Myelin Map (qMM) and preliminary reported its utility in MS patients, particularly for depicting remyelination. This current study aimed to analyze clinical factors associated with qMM-supported remyelination in a series of consecutive MS patients initiating different disease-modifying drugs (DMDs), and to examine the utility and the feasibility of qMM in daily clinical practice. Methods Data from sequential patients with relapsing-remitting MS (RRMS) initiating one of the following DMDs at our center were collected: interferon β (IFN β), glatiramer acetate (GA), fingolimod (FTY), dimethyl fumarate (DMF), or natalizumab (NTZ). After treatment initiation, qMM was performed at 6-month intervals and the resulting images analysed for evidence of remyelination. Results 48 patients with RRMS were included: 22 with DMF, 14 with FTY, 4 with GA, 8 with NTZ, and 0 with IFN β. qMM revealed qMM-remyelination in 22 patients (45.8%), including 10 receiving DMF, 6 receiving FTY, 1 receiving GA, and 5 receiving NTZ. qMM-remyelination was significantly associated with younger age in the NTZ group(p = 0.036), and associated with female sex in the DMF group(p = 0.015). Conclusions This study demonstrated the potential clinical utility of qMM for visualizing remyelination in MS patients and fine-tuning their pharmacotherapy. Two potential clinical factors promoting qMM-remyelination were identified: female sex with DMF and younger baseline age with NTZ; a larger prospective study is warranted to confirm these results.