In the current “Controversies in Neurology” series, the contentious issue arises as to whether we have sufficient evidence to designate neuromyelitis optica (NMO) (Devic disease) as a disease entity distinct from multiple sclerosis (MS).1,2 As with many such debates, there will be “lumpers” (similar disorders should be characterized under a common rubric) and “splitters” (similarly appearing disorders should be differentiated on a pathophysiologic, genetic, or phenotypic basis).
Frohman EM, Kerr D. Is Neuromyelitis Optica Distinct From Multiple Sclerosis?Something for “Lumpers” and “Splitters”. Arch Neurol. 2007;64(6):903–905. doi:10.1001/archneur.64.6.903