Fig. 1

Brain magnetic resonance imaging (MRI) of the present patient with irreversible metronidazole-induced encephalopathy (MIE). a-c Diffusion-weighted imaging (DWI) at the time of onset shows hyperintensities in the splenium of the corpus callosum (white arrowheads, b) and the deep white matter of the bilateral parietal lobes (white arrowheads, c). d-f Fluid-attenuated inversion recovery (FLAIR) imaging of the brain shows hyperintensities in the dentate nuclei (white arrows, d), despite a lack of signal abnormalities in the corpus callosum and parietal deep white matter (e, f). g-i Apparent diffusion coefficient (ADC) values are reduced in the parietal lobes and splenium of the corpus callosum (arrowheads). Follow-up MRI of the brain 2 years after metronidazole withdrawal reveals near-complete resolution of abnormal intensities on DWI (j-l). m The abnormal signal intensities in the dentate nuclei have also disappeared. (n, o) However, widespread hyperintensities with diffuse brain atrophy are evident in the splenium of the corpus callosum and deep white matter including the parietal lobes on FLAIR (white arrowheads)