Tumefactive brain lesion with rapid cavity formation associated with anti-aquaporin-4 antibody

Long-term outcomes of ADEM-like and tumefactive presentations of CNS demyelination: a case-comparison analysis

A minority of initial multiple sclerosis (MS) presentations clinically or radiologically resemble other central nervous system (CNS) pathologies, acute disseminated encephalomyelitis (ADEM) or tumefactive demyelination (atypical demyelination presentations). With the aim of better defining the long-term outcomes of this group we have performed a retrospective cohort comparison of atypical demyelination versus 'typical' MS presentations. Twenty-seven cases with atypical presentations (both first and subsequent demyelinating events) were identified and compared with typical MS cases. Disease features analysed included relapse rates, disability severity, whole brain and lesion volumes, lesion number and distribution. Atypical cases represented 3.9% of all MS cases. There was considerable overlap in the magnetic resonance imaging (MRI) features of ADEM-like and tumefactive demyelination cases. ADEM-like cases tended to be younger but not significantly so. Atypical cases showed a trend towards higher peak expanded disability severity score (EDSS) score at the time of their atypical presentation. Motor, cranial nerve, cerebellar, cerebral and multifocal presentations were all more common in atypical cases, and less likely to present with optic neuritis. Cerebrospinal fluid (CSF) white cell counts were higher in atypical cases (p = 0.002). One atypical case was associated with peripheral blood myelin oligodendrocyte glycoprotein (MOG) antibodies, but subsequent clinical and radiological course was in keeping with MS. There was no difference in long-term clinical outcomes including annualised relapse rates (ARR), brain volume, lesion numbers or lesion distributions. Atypical demyelination cases were more likely to receive high potency disease modifying therapy early in the course of their illness. Despite the severity of initial illness, our cohort analysis suggests that atypical demyelination presentations do not confer a higher risk of long-term adverse outcomes.

Atypical inflammatory demyelinating lesions and atypical multiple sclerosis

Atypical idiopathic inflammatory demyelinating disorders (IIDDs) of the brain have long been known to be disorders closely related to multiple sclerosis (MS), despite having distinctive clinical and radiological characteristics. Originally, they mostly corresponded to acute-onset variants of MS that classically had poor prognoses, such as Baló's concentric sclerosis, Marburg variant of MS and Schilder's disease, and their relationship with MS was based on their shared pathological findings and the co-occurrence of these variants in patients with typical MS. More recently, other atypical disorders, such as solitary sclerosis, have also been described as belonging to the MS spectrum, raising the question of their links with MS. Meanwhile, multiple MS mimics have been described and need to be considered in the differential diagnosis of MS. In addition, thorough characterization of these atypical entities, including advanced MRI and biological studies, is now warranted to further improve their management.