In Cree's summary of NMO in Seminars in Neurology, women predominated by 2.3:1, the mean age of onset was 37, 45 % presented with ON, 38 % with myelitis, 17 % with both, 76 % had a normal brain MRI, more than half had a CSF pleocytosis, and had PMN's in the CSF . The ratio of polyphasic to monophasic disease was 1.8 : 1. Although the prognosis was poor , there were benign cases. Galetta stressed that although LETM (Long extensive transverse myelitis) was characteristic, skip areas also occurred in the cord.
Although the brain lesions were unique according to the Mayo article, a certain percentage has ovoid or periventricular lesions indistinguishable from MS. In patients with NMO with transverse myelitis, recurrence was more common (vice versa). Hiccups and nausea imply a medullary lesion and occur in 17 %. NMO is positive from the very earliest stage. Rarely, patients are NMO negative or have antibodies to another antigen such as MUSK. The complement mediation of destruction is characteristic.
A spectrum of disease probably exists including idiopathic recurrent isolated LETM, recurrent ON with a negative brain MRI, and Asian optic-spinal MS. Standard MS therapies are not effective but specific NMO therapies can be not only effective but occassionally dramatically so in seemingly hopeless cases. Elliott Frohmann described a patient who was limited to movement of one finger, who was treated with high dose IV methotrexate, and recovered completely including driving, living independently, raising her children.