Vigabatrin-associated reversible MRI signal changes in patients with infantile spasms

P>Purpose: To evaluate the magnetic resonance imaging (MRI) of pediatric patients with infantile spasms (IS) treated with vigabatrin (VGB) in order to investigate whether VGB affects the brain. Methods: One hundred seven pediatric patients diagnosed with IS and treated with (n = 95) >= 120 mg/kg/day VGB or without (n = 12) VGB were included. MRI and diffusion-weighted imaging (DWI) were retrospectively analyzed. Results: Of the patients who had MRI scans during, but not before, VGB treatment (n = 81), 25 (30.9%) exhibited abnormal MRI signal intensity and/or restricted DWI in the deep gray nuclei and brainstem. Follow-up scans (performed in 15 of the 25 patients) revealed that these changes were reversible upon withdrawal of the medication. Analysis of patients undergoing scans before, during, and after VGB treatment (n = 14) revealed that four patients had abnormal MRI signal during treatment with VBG, two of whom reversed with cessation of VGB, one reversed without cessation of VGB, and another had persistent abnormal signal while being weaned from the VGB. Patients who had not received VGB treatment (n = 12) displayed normal imaging. Younger infants (< 12 months) and those with cryptogenic IS were more likely to develop abnormal signal changes on MRI during VGB treatment. Discussion: In pediatric patients, VGB induces reversible MRI signal changes and reversible diffusion restriction in the globi pallidi, thalami, brainstem, and dentate nuclei. The risk for this phenomenon was greater in younger infants and patients with cryptogenic IS.