We read with great interest the article by de Seze et al1 about disseminated encephalomyelitis (DEM) and multiple sclerosis (MS) in the October 2007 issue of the Archives. We agree that in the current literature many diseases are regarded as acute DEM (ADEM) and that diagnostic criteria for ADEM are needed.
However, the classification of patients into ADEM, multiphasic DEM (MDEM), and MS groups in the article by de Seze and colleagues is confusing. Studies performed both in children and in adults have differentiated 3 types of DEM: (1) monophasic ADEM, which represents 1 demyelinating episode; (2) recurrent DEM (RDEM), which represents relapses with symptoms similar to those in the first demyelinating episode; and (3) MDEM, which represents relapses with symptoms of locations other than those in the first demyelinating episode.2- 4 de Seze and colleagues do not distinguish RDEM and MDEM as 2 DEM variants from MS. This is of particular importance, as acknowledged by de Seze and colleagues, because current MS criteria cannot distinguish MS from MDEM.
Brinar VV, Habek M. Monophasic Acute, Recurrent, and Multiphasic Disseminated Encephalomyelitis and Multiple Sclerosis. Arch Neurol. 2008;65(5):672-677. doi:10.1001/archneur.65.5.675