Neuromyelitis optica, also known as Devic disease, was identified in the 19th century, is one of the inflammatory idiopathic demyelinating diseases of the central nervous system, often mistaken for severe multiple sclerosis. In 1999 it had been proposed diagnostic criteria for neuromyelitis optica, but in 2006 these criteria were revised by Dean Wingerchuck. These criteria are 99% sensitive and 90% specific for differentiating neuromyelitis optica from multiple sclerosis that present with optic neuritis or a myelitis syndrome. In the following article we present clinical, spinal and cerebral MR imaging, serological and aspects of cerebrospinal fluid examination features of neuromyelitis optica and the revised criteria of neuromyelitis optica established in 2006. The recently identified serum antibody biomarker: neuromyelitis optica immunoglobulin G (NMO Ig G), which target aquaporin 4 water channel, distinguish neuromyelitis optica from multiple sclerosis, is one of the revised criteria of neuromyelitis optica.