Central Nervous System Involvement in the Eosinophilia-Myalgia Syndrome

A patient with eosinophilia-myalgia syndrome developed progressive central nervous system involvement that did not improve despite discontinuation of L- tryptophan therapy. Neurologic impairment was manifested initially by spastic monoparesis, which was improved by treatment with methylprednisolone and hydroxyurea. Recurrence of weakness was accompanied by gait ataxia, dysphagia, and complaints of a gradual decline in memory and concentration. Neuropsychological testing identified a broad pattern of cognitive deficits suggestive of a subcortical dementia, and magnetic resonance imaging demonstrated multiple high-signal lesions in the white matter. Cognitive deficits appear to be underrecognized in patients with the eosinophilia- myalgia syndrome. The response of our patient's initial symptoms to corticosteroid therapy suggests a possible role for autoimmune mechanisms in the pathogenesis of central nervous system involvement in the eosinophilia- myalgia syndrome. Neuropsychological evaluation should be performed in patients with cognitive complaints to delineate the full spectrum of central nervous system impairment associated with the eosinophilia-myalgia syndrome.