Objects: During the last decades there have been various attempts to define the characteristics of white matter inflammatory diseases. Most of the authors concerned agree in considering Schilder's myelinoclastic diffuse sclerosis (SD), Devic's neuromyelitis optica (NMO) and Balo's concentric sclerosis to be variants of typical multiple sclerosis (MS). Moreover, in childhood even typical MS presents more aggressive behaviour, with frequent evidence of giant, tumefactive, necrotic or haemorrhagic plaques.
Methods: The authors review the literature and cite atypical cases that appear to be intermediate between MS and SD, NMO and SD.
Conclusions: Finally, some critical revisions are proposed concerning cases with clinical presentation, history, laboratory and MR findings intermediate between those of acute disseminated encephalomyelitis and of MS.