Boomerang in the Brain

We are presenting a case who presented with slurring of speech, headache, and difficulty in maintaining balance for the past 8 h before presentation. The patient was working in paper printing workshop which involved used of printing dyes for the past 20 years and was working without any personal protective equipment. On examination, the patient had normal vitals but abnormal finger-nose test, the presence of dysdiadochokinesia, abnormal heel-knee test bilaterally, and ataxic gait but no nystagmus. Blood investigations of the patient were in normal range. Cerebrospinal fluid was normal microscopically and biochemically. Magnetic resonance imaging (MRI) brain was done, which showed bilateral symmetric T2 and fluid-attenuated inversion recovery hyperintensities involving the vestibular and dentate nuclei of the cerebellum [Figure 1] and corpus callosum. Area of hyperintensity involving the corpus callosum predominantly splenium, which showed restricted diffusion [Figure 2] with hypointense signal on Apparent Diffusion Coefficient (ADC) map, which appears as a “Boomerang” [Figure 3]. The patient's complaints improved during hospital stay, and cerebellar signs disappeared by the 10th day. The patient was discharged and was advised not to engage in occupation involving printing dyes. Repeat MRI brain done after 12 weeks was normal [Figure 4]. A diagnosis of toxic encephalopathy with acute reversible cerebellar ataxia was made