Magnetic Resonance Spectroscopic Findings of Chronic Lesions in Two Subtypes of Multiple Sclerosis: Primary Progressive Versus Relapsing Remitting

Nasrin Rahimian,Alipasha Meysamie,Kavous Firouznia,Hamidreza Saligheh Rad,Mohammad Hossein Harirchian,Seyed Amir Ebrahimzadeh,Hamideh Vafaiean

doi:10.5812/iranjradiol.11336

Abstract

BackgroundMultiple sclerosis (MS) is a highly prevalent cause of neurological disability and has different clinical subtypes with potentially different underlying pathologies. Differentiation of primary progressive multiple sclerosis (PPMS) from relapsing remitting multiple sclerosis (RRMS) could be difficult especially in its early phases.ObjectivesWe compared brain metabolite concentrations and ratios in patients with PPMS and RRMS by magnetic resonance spectroscopic imaging (MRSI).Patients and MethodsThirty patients with definite MS (15 with RRMS and 15 with PPMS) underwent MRSI and their non-enhancing lesion metabolites were measured. N-acetyl aspartate (NAA), Creatine (Cr), Choline (Cho), NAA/Cr and NAA/Cho were measured and compared between the two MS subtypes.ResultsWhen the two MS groups were compared together, we found that Cr was significantly increased (P value=0.008) and NAA/Cr was significantly decreased (P value=0.03) in non-enhancing lesions in PPMS compared with RRMS. There was no significant difference in NAA, Cho or NAA/Cho between the two MS subtypes.ConclusionMRS is a potential way to differentiate PPMS and RRMS.

Highlights

Multiple sclerosis (MS) is a highly prevalent cause of neurological disability and has different clinical subtypes with potentially different underlying pathologies
Implication for health policy/practice/research/medical education: This study suggests a potential role for magnetic resonance spectroscopy (MRS) in the differentiation of primary progressive multiple sclerosis from relapsing remitting multiple sclerosis
T2 lesion burden has a poor correlation with disability in MS [22, 23] and it cannot differentiate the subtypes of the disease [23]

Summary

Introduction

Multiple sclerosis (MS) is a highly prevalent cause of neurological disability and has different clinical subtypes with potentially different underlying pathologies. Patients and Methods: Thirty patients with definite MS (15 with RRMS and 15 with PPMS) underwent MRSI and their non-enhancing lesion metabolites were measured. The most common MS subtype affecting approximately 85% of the patients is termed relapsing remitting MS (RRMS) that is characterized by an acute onset of symptoms that remit spontaneously. Another 10-15% of patients experience disease progression from the onset. This is termed primary progressive multiple sclerosis (PPMS) [1, 2]

Objectives

Methods

Conclusion