MR features of metronidazole-induced encephalopathy.

To cite: Sandip S, Afshan I, Khandelwal RK. BMJ Case Rep Published online: [please include Day Month Year] doi:10.1136/bcr-2015212609 DESCRIPTION Metronidazole, a commonly used antimicrobial drug, is rarely known to cause encephalopathy irrespective of dose and duration of intake. It poses a diagnostic challenge clinically because of its rarity. MR is an important adjunct in diagnosing this condition because of characteristic features on it. In the previous case reports, typical brain lesions have been described in the cerebellar dentate nucleus, midbrain, dorsal pons, medulla and splenium of the corpus callosum. MR is also useful in follow-up, since most of the lesions are reversible and correspond to the areas of vasogenic oedema on diffusion-weighted imaging (DWI), though few of them may represent cytotoxic oedema. Here, We describe MRI features of metronidazole-induced encephalopathy in our case report. A 48-year-old woman was taking tab metronidazole (800 mg three time a day) for amoebic liver abscess and presented with dizziness, headache and altered behaviour. MRI revealed symmetric areas of T2-weighted and fluid-attenuated inversion recovery hyperintensity involving bilateral dentate nuclei and deep cerebellar white matter (white arrow in figure 1A, C, D) and bilateral superior olivary nuclei in dorsal pons(white arrow in figure 1B). The corresponding areas appeared hypointense on T1-weighted imaging (white arrow in figure 1E). No evidence of restricted diffusion was seen on DWI and apparent diffusion coefficient map (figure 1F, G). On discontinuation of the drug, patient’s clinical symptoms improved remarkably.