Neuromyelitis optica shows hypermetabolism in 18-fluorodeoxyglucose positron emission tomography

Neuromyelitis optica (NMO) is an idiopathic severe necrotic inflammatory disease that mainly causes optic neuritis and myelopathy. Although it usually shows typical magnetic resonance imaging (MRI), the spinal lesions in NMO might sometimes mimic neoplasms or multiple sclerosis (MS) plaques. We present two NMO patients who showed marked hypermetabolism using 18-fluorodeoxyglucose (FDG) positron emission tomography (PET) imaging at spinal cord lesions, corresponding to the gadolinium-enhanced site. As MS plaques typically show hypometabolism, FDG-PET imaging might be a useful and specific tool for the differential diagnosis of MS and NMO. Furthermore, NMO lesions should not be misdiagnosed as neoplasms simply because of the presence of hypermetabolism in FDG-PET imaging. (Clin. Exp. Neuroimmunol. doi: 10.1111/j.1759-1961.2011.00026.x, 2012)