Lesion morphology at 7 Tesla MRI differentiates Susac syndrome from multiple sclerosis
Multiple Sclerosis Journal, 07/05/2012
Wuerfel J et al. – At 7T MRI, plaques in multiple sclerosis (MS) patients and patients with Susac syndrome differed substantially with respect to morphology and pattern. Thus, lesion morphology at 7T (i) may serve as a marker to distinguish Susac syndrome from MS and (ii) reflects a different pathophysiological mechanism underlying Susac syndrome, for example microinfarction rather than demyelination.Methods
- Five patients suffering from Susac syndrome, 10 sex– and age–matched patients with relapsing–remitting MS (median Expanded Disability Status Scale (EDSS) score 1.5) and 15 matching healthy controls were investigated at 7 Tesla MRI.
- The protocol included T1–weighted MPRAGE, T2*–weighted FLASH, and TIRM sequences.
- Almost all T2* FLASH lesions in patients with MS were centred by a small central vein (325 lesions; 92%) and often showed a small hypointense rim (145 lesions; 41%).
- In contrast, white matter lesions in Susac syndrome exhibited a perivascular setting significantly less frequently (148 lesions; 54%, p=0.002), and very rarely exhibited a hypointense rim (12 lesions; 4%, p=0.004).
- Furthermore, in addition to callosal atrophy, Susac patients showed cerebrospinal fluid–isointense lesions within the central part of corpus callosum that are not commonly seen in MS.