Walsh & Hoyt: Diagnosis

Although numerous authors have proposed diagnostic criteria for neuromyelitis optica, none has achieved widespread acceptance. It may be impossible to differentiate between neuromyelitis optica and MS on clinical grounds alone, and some authors believe, as noted above, that they are simply variants of the same disease. Indeed, review of the literature suggests that some cases diagnosed as ""neuromyelitis optica"" are, in fact, examples of MS. Nevertheless, not only are there important pathologic differences and differences in CSF findings between the two diseases, but there are also important clinical differences between these two disorders. First, neuromyelitis optica is not uncommon in the first decade of life, whereas MS rarely occurs in patients under 10 years of age. Second, the occurrence of bilateral optic neuritis associated with myelitis is rarely recorded in cases of pathologically proven MS. Third, bilateral blindness is extremely unusual in MS but is the rule in neuromyelitis optica.