Sudden onset aphasic hemiplegia: an unusual manifestation of disseminated encephalomyelitis.

The association of the sudden onset of aphasia with hemiplegia, hemisenosry defect, and facial palsy, with MRI evidence of white matter lesions, requires differentiation between multiple sclerosis (MS) and acute disseminated encephalomyelitis (ADEM). We have observed eight patients with such a syndrome, all of whom were originally diagnosed as multiple sclerosis, but who, on closer examination, turned out to be instances of disseminated encephalomyelitis. The patterns of demyelination seen in T2-weighted MRI are quite different in both conditions. In two of our patients, MRI reverted to normal after the treatment; in others, the images remained unchanged. A review of the reported cases of multiple sclerosis presenting with the acute onset of aphasia, reveals that the majority of them are, in reality, instances of acute disseminated encephalomyelitis with a much better prognosis. Most of these cases are monophasic and immunomodulatory treatment is inappropriate.