AQP4 and neuromyelitis optica: Autoimmune and infectious workup was also within normal limits, including two negative blood cultures without growth, negative anti-neuromyelitis optica (anti-NMO) antibody (anti-aquaporin 4 ab), negative anti-myelin oligodendrocyte glycoprotein (anti-MOG) antibody, negative antinuclear antibody (ANA), normal methylmalonic acid levels, normal serum copper, negative Lyme titers, and West Nile serum negative.