Central nervous system involvement in the eosinophilia-myalgia syndrome

A patient with eosinophilia-myalgia syndrome developed progressive central nervosa 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 methyl-prednisolone 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.