Leukoencephalopathy induced by levamisole alone for the treatment of recurrent aphthous ulcers.

We report imaging and clinical findings of leukoencephalopathy occurring after levamisole. The lesions were hypoattenuating on CT and appeared as multifocal oval or elliptical foci in the white matter or along the subependymal veins on MRI. Most lesions resolve after prompt withdrawal of levamisole. Detailed history taking is important for diagnosing levamisole-induced leukoencephalopathy because multiple sclerosis and acute disseminated encephalomyelitis cannot be differentiated by neuroimaging findings alone.