Acute symptomatic seizure due to tacrolimus-related encephalopathy after liver transplantation: two case reports

Liver transplantation is suitable for acute and chronic liver diseases that cannot be cured by other methods. Immunosuppressants such as azathioprine, methylprednisolone, cyclophosphamide, cyclosporine A, and tacrolimus have been applied to prevent rejection after liver transplantation. Among them, tacrolimus is generally effective in resisting rejection, and its main adverse reaction is nephrotoxicity. Tacrolimus-induced seizures are rarely reported. The present report describes trismus, restlessness, and generalized muscle twitching in a 44-year-old man and a 59-year-old man who received tacrolimus after liver transplantation. Tacrolimus-induced epilepsy was diagnosed by clinical symptoms and video-electroencephalography. After the patients developed epileptic symptoms, they received intramuscular injections of diazepam and phenobarbital. When the symptoms were relieved, the patients were treated with oral levetiracetam tablets. The tacrolimus was immediately stopped, and the epilepsy symptoms gradually disappeared after treatment with sedatives and levetiracetam. The patients continued taking the levetiracetam for approximately 2 weeks. No evidence of seizures occurred during the next 8 months. Although tacrolimus is reportedly effective against rejection after liver transplantation, tacrolimus-induced epilepsy should be carefully managed to prevent death. Additionally, epilepsy may rarely occur in patients with a normal blood concentration of tacrolimus. Further study on the mechanism of such neurological complications is needed.