<unk> , also known as<unk><unk><unk>  or<unk>  fulminant<unk><unk> , is considered one of the<unk><unk>  borderline diseases, which is a collection of diseases classified by some as MS variants and by others as different diseases. Other diseases in this group are neuromyelitis optica (NMO), Balo concentric<unk> , and Schilder's disease. The graver course is one form of malignant<unk><unk> , with patients reaching a significant level of disability in less than five years from their first symptoms, often in a matter of months. Sometimes<unk>  MS is considered a synonym for tumefactive MS, but not for all authors.
Marburg acute multiple sclerosis
Rasmussen's encephalitis
La Crosse encephalitis
Bickerstaff brainstem encephalitis
Saint Louis encephalitis
Powassan encephalitis
Barré–Liéou syndrome
Anti-NMDA receptor encephalitis