Multifocal Demyelinating Leukoencephalopathy Induced by Levamisole Therapy

The neurotoxic effects of levamisole therapy have been rarely reported. In this article, we report two patients who developed multifocal demyelinating leukoencephalopathy (MDL) after levamisole treatment. Clinically, they had dizziness, nausea, vomiting, confusion, mental dullness, speechlessness, and memory impairment after the treatment. The total dosage of levamisole was 300 mg and 1800 mg, respectively. The onset of symptoms was acute or subacute, from a few hours to several weeks. Initial brain magnetic resonance imaging (MRI) demonstrated diffuse multifocal enhancing lesions in the subcortical white matter. After the withdrawal of levamisole, and during the follow-up period, the neurological and neuropsychological manifestations and serial brain MRI improved gradually. We conclude that levamisole treatment may induce MDL, and that the brain MRI changes may correlate well with the recovery of clinical features and neuropsychological findings. In addition, early steroid treatment is crucial, and the neurotoxic effect of levamisole is not dose-dependent and may be idiosyncratic or immune-mediated. (Chang Gung Med J 2006;29(4 Suppl):90-6)