[Diagnostic criteria of borderline forms of multiple sclerosis].

Border forms of multiple sclerosis (MS) can be separated in two groups: either they are variants of MS or they are distinct from MS but they share several characteristics with MS thus representing for some of them a continuum with MS. All these entities are central nervous system demyelinating diseases. Here we describe, for the first group, MS in childhood, MS in elderly subjects, Balò's concentric sclerosis, Schilder's myelinoclastic diffuse sclerosis and MS simulating a mass lesion, and for the second group, acute disseminated encephalomyelitis and Devic's neuromyelitis optica.