Introduction
Search Strategy and Selection Criteria
Diagnosis and Classification of PPMS
Relapsing-remitting multiple sclerosis | ||
Number of lesions with objective clinical evidence | Additional data needed for a diagnosis of multiple sclerosis | |
≥ 2 clinical attacks | ≥ 2 | None |
≥ 2 clinical attacks | 1 (as well as clear-cut historical evidence of a previous attack involving a lesion in a distinct anatomical location) | None |
≥ 2 clinical attacks | 1 | Dissemination in space demonstrated by an additional clinical attack implicating a different CNS site or by MRIa |
1 clinical attack | ≥ 2 | Dissemination in time demonstrated by an additional clinical attack or by MRIb OR demonstration of CSF-specific oligoclonal bands |
1 clinical attack | 1 | Dissemination in space demonstrated by an additional clinical attack implicating a different CNS site or by MRIa AND Dissemination in time demonstrated by an additional clinical attack or by MRIb OR demonstration of CSF-specific oligoclonal bands |
Primary progressive multiple sclerosis | ||
Clinical presentation | ≥ 1 year of disease progression, which can be determined either prospectively or retrospectively with 2 of the 3 following criteria: | |
MRI criteria | 1. One or more T2-hyperintense lesions characteristic of multiple sclerosis in one or more typical locationsc 2. Dissemination in time on spinal cord MRI (at least two T2-hyperintense lesions) 3. Positive results from the cerebrospinal fluid analysis (i.e., presence of oligoclonal bands) |
RRMS | PPMS | |
---|---|---|
Clinical presentation | At least 1 clinical attack | 1 year of disease progression, clinical attack is not obligatory |
Results from additional examination | ||
Brain MRI (DIS) | ≥ 2 lesion (required) | ≥ 1 lesion (not required) |
Spinal cord MRI (DIS) | ≥ 1 lesion, possible | ≥ 2 lesions, one of the paraclinical criteria |
MRI Characteristics of PPMS Patients
Brain
Gadolinium-Enhancing Lesions (Gd+ Lesions)
Focal T2-weighted Lesions
Leptomeningeal Enhancement
T1-weighted Lesions (“Black Holes”)
“Dirty Appearing White Matter” (DAWM)
Slowly Expanding/Evolving Lesions (SELs)
Brain Atrophy
Spinal Cord MRI in PPMS Patients
Focal T2-weighted Lesions
Gadolinium-enhancing Lesions (Gd+ Lesions)
Diffuse Spinal Cord Abnormalities
Spinal Cord Atrophy
Nonconventional MRI (non-cMRI)
MRI feature | Characteristic | Reference |
---|---|---|
Brain | ||
Number of Gd+ lesions | Low | |
Number of T2-weighted lesions | Low | |
Black holes (T1-weighted lesions) | More often than in RRMS | |
Cortical lesions | Very often | |
Leptomeningeal enhancement | Often | |
Dirty appearing white matter | Very often | |
Slowly expanding/evolving lesions | Often | |
Rim-positive lesions | Often | |
Atrophy | Very often | |
MTR from NAWM | Lower than in RRMS | |
MTR from NAGM | Lower than in RRMS | |
DWI (MD) T2- WI lesions, NAWM, NAGM | Lower than in patients with SPMS | |
H‑MRS (single voxel) | ||
Cho/Cr NAWM | Higher compared with RRMS | [133] |
NAA/Cr in chronic non-enhancing focal lesions | Lower compared with RRMS | [136] |
CSI | ||
Level of glutathione | Lower than in patients with RRMS | [137] |
SWI in the thalamus | Lower than in patients with RRMS | [140] |
Spinal cord | ||
Number of Gd+ lesions | Very low | [14] |
T2-weighted lesions (size, location) | As in RRMS patients (usual) | |
Diffuse mild hyperintensity | Very often | |
Atrophy | Very often | |
MTR from cervical NAWM and NAGM | Higher than in patients with SPMS | [118] |
DWI (FA) | Lower than in healthy control | [129] |
DWI (MD) | Higher than in healthy control | [129] |