Atypical presentation of tacrolimus encephalopathy in a kidney transplant patient

Context: Neurological complications triggered by tacrolimus in transplant patients can occur in a common way. Tacrolimus encephalopathy is a rare presentation. The present case follows atypical patterns of this disease, since it presented as aphasia, seizure and unusual radiological findings. Case report: A 52--year--old female patient complaining of severe headache for 3 days, associated with difficulty in formulating phrases and confusion. She had a history of nephrolithiasis, kidney transplantation (2020), hypertension and diabetes, using tacrolimus, mycophenolate and prednisone. In the hospital, she had a global aphasia and episodes of generalized tonic-- clonic seizures, being medicated with levetiracetam, phenytoin and acyclovir, maintaining good seizure control, but persisting aphasic. Brain MRI showed an extensive hypersignal in T2/FLAIR involving the left parieto-- occipito-- temporal cortical subcortical region. CSF showed: protein 91 mg/dL, glucose 143 mg/dL and leukocytes 2 cells/mm³. Negative infectious screening was performed in the CSF using FilmArray encephalitis/meningitis panel. Hypothesized an encephalopathy caused by tacrolimus we discontinued the medication and after 3 days, the patient had a significant clinical improvement, no aphasia and drastic reduction in the hypersignal extension. The patient was discharged from service using cyclosporine and prednisone. Conclusions: Tacrolimus crosses the blood--brain barrier, having a direct action on the CNS. Encephalopathy triggered by its toxicity is capable of producing several radiological patterns. After discard infectious encephalitis, it is of utmost importance to consider tacrolimus--induced encephalopathy -- due to rapid clinical and radiological remission after discontinuing the drug.