[Differential diagnosis of delayed encephalopathy induced by anthelmintic imidazoles]

Anthelmintic imidazoles induced delayed encephalopathy (AIIDE) is frequently encountered and has usually been misdiagnosed as sporadic encephalitis of unknown cause (SEU). This study was carried out to facilitate differentiation of the two diseases. The records of 202 cases of AIIDE were reviewed and the clinical features analyzed. As a results, 7 diagnostic criteria for AIIDE were proposed as follows: (1) history of exposure to anthelmintic before the onset; (2) presence of a latent period of of 2 to 5 weeks; (3) onset of the disease acute or subacute; (4) presence of neuropsychiatric symptoms and signs resulted from multifocal cerebral damage; (5) Fulfillment of two of the following conditions; (a) subinflammatory change in CSF with elevation of IgG; (b) diffuse slow waves in EEG during early stage; (c) characteristics of acute demyelinating encephalopathy in brain biopsy; (6) good therapeutic effect of adrenal corticosteroids; (7) exclusion of other neuropsychiatric disorders in a fallow-up period of one year. AIIDE is a new disease entity and its diagnosis is mainly based on the clinical features. EEG, CT or MRI are important diagnostic measures, but history of exposure to anthelmintic is the most important criterion. Multifocal hemorrhagic leukoencephalopathy is its main pathologic feature.