Acute encephalopathy and idiopathic hypereosinophilic syndrome: clinical and MRI response to early steroid treatment

A 31-year-old woman with hypereosinophilic syndrome developed left hemiplegia with confusion over a few hours. Brain magnetic resonance imaging (MRI) showed a diffuse meningeal gadolinium enhancement and periventricular nodular lesions. After 20 months of continuous steroid treatment, the patient is clinically asymptomatic and there were an obvious regression of MRI abnormalities. These findings indicate that an early steroid treatment is able to prevent irreversible damage in hypereosinophilic syndrome.