Finding NMO

Since the discovery in 2004 of NMO-IgG, the autoantibody associated with neuromyelitis optica (NMO),1 neurologists are increasingly relying on the NMO-IgG test to rule in or rule out NMO. Related disorders like optic neuritis (ON), transverse myelitis (TM), acute disseminated encephalomyelitis (ADEM), and longitudinally extensive TM (LETM; ≥3 spinal cord vertebral segments) can all be monophasic or multiphasic, can occur together or individually, and can occur in adults or children. Similarly, multiple sclerosis (MS) is often confused with these disorders, especially early in the disease. But little is known about the prevalence of NMO-IgG in children presenting with these disorders. In the current issue of Neurology ®, Dr. Banwell at the Hospital for Sick Children in Toronto, Canada, along with colleagues in Argentina and Montreal, and Dr. Pittock and colleagues at the Mayo Clinic in Rochester, Minnesota, aim to determine the seroprevalence of NMO-IgG in children with NMO and related disorders.2 This is the first published characterization of NMO-IgG seroprevalence in children and includes 87 patients with NMO, TM, ON, ADEM +TM, and MS from two centers, Toronto and Buenos Aires. Diagnoses were based on well-established clinical and radiologic criteria, and clinicians were blinded to the NMO-IgG status for the purpose of this study. The results …