An order for the MS spectrum

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These authors expand the classification for atypical MS to 4 new variants, according to the lesion type:

- Classic atypical MS: infiltrative, megacystic, Baló’s-like, and ring-like
- New atypical MS: Tumefactive demyelinating lesion (TDL)-onset MS, Acute disseminated encephalomyelitis (ADEM)-like MS, Cavitary MS and Leukodystrophy-like MS

Multiple sclerosis with atypical MRI presentation

https://www.sciencedirect.com/science/a ... 4818305546

Introduction

Multiple sclerosis (MS) diagnosis is based on McDonald criteria that were recently modified to increase sensitivity (Thompson et al., 2018). Besides classical MS fulfilling criteria, there are some MS patients with atypical magnetic resonance imaging (MRI) findings.

Some atypical MS variants such as Marburg's type, Schilder's disease or Baló’s concentric sclerosis have been known for a long time. Beyond these historical descriptions, a broad spectrum of atypical demyelinating syndromes has been identified, which encompasses poorly understood conditions with unclear relation with MS, along with well immunologically characterized diseases (Hardy et al., 2016).

A MRI classification of atypical idiopathic inflammatory demyelinating lesions (IIDL) in four subtypes has been done: infiltrative, megacystic, Baló’s-like, and ring-like (Wallner-Blazek et al., 2013). Such lesions were associated with typical MS lesions in more than half of the cases (Wallner-Blazek et al., 2013).

Nevertheless, some patients with MS and atypical MRI presentation do not correspond to these subgroups. In these patients, differential diagnosis between MS and other inflammatory demyelinating syndromes, as well as other conditions like tumors or genetic leukoencephalopathies could be challenging (Brownlee et al., 2017; Weisfeld-Adams et al., 2015).

Our objectives are to extend the described phenotypes of patients with atypical MS, and to define clinical and radiological clues for diagnosis.

Material and methods

Patients with atypical MS were identified through a nationwide retrospective study. We established a five(?) groups classification: Tumefactive demyelinating lesion (TDL)-onset MS, Acute disseminated encephalomyelitis (ADEM)-like MS, Cavitary MS and Leukodystrophy-like MS. All the patients meeting our radiological criteria for atypical MS were included.

Results

A total of 57 patients met the inclusion criteria. 7 cases were classified in the TDL-onset group, 10 in the ADEM-like group, 26 in the cavitary group and 14 in the leukodystrophy-like group. Overall risk of conversion to MS after an isolated TDL was around 30% at five years. Patients in the TDL-onset and ADEM-like groups globally presented an acute onset and a relapsing-remitting evolution. Conversely, patients in the cavitary and leukodystrophy- groups largely evolved with a progressive and severe course.