Paroxysmal dystonia as a rare initial manifestation of multiple sclerosis.

Multiple sclerosis is an uncommon disease in childhood and adolescence and is rarely associated with movement disorders other than tremor. The differential diagnosis is difficult to establish when, particularly, movement disorder presents as the initial manifestation of multiple sclerosis. Video-electroencephalography monitoring is the gold-standard method for the differential diagnosis of epileptic and paroxysmal nonepileptic events, including movement disorders and psychogenic seizures. This article presents a patient with paroxysmal dystonia secondary to multiple sclerosis who previously was diagnosed and treated as having conversion disorder and epilepsy. The utility of video-electroencephalography monitoring during the process of differential diagnosis is discussed.