Tacrolimus-associated mutism after orthotopic liver transplantation

Background. Mutism/speech apraxia has been well documented as a toxic effec t of cyclosporine after liver transplantation but has been reported only ra rely with tacrolimus. Brain imaging with magnetic resonance or computed tom ography has failed to demonstrate abnormalities in affected patients. Methods. We present the first example of an acute onset of loss of speech a ssociated with a sudden elevation of serum tacrolimus level after successfu l orthotopic liver transplantation. We also describe the positron emission tomography (PET) scan of this patients brain. Results. PET scan imaging of the brain was abnormal, demonstrating decrease d metabolism in the posterior temporo-parieto-occipital regions. Statistica l probability mapping revealed additional areas of hy pometabolism in the c ingulate gyrus. Conclusions. PET scan revealed abnormalities of the brain in a patient with tacrolimus-induced mutism. The cingulate gyrus may play a role in the muti sm/speech apraxia syndrome seen with cyclosporine/tacrolimus neurotoxicity.