Reduced uptake of FDOPA PET in end-stage liver disease with elevated manganese levels

Objective: To investigate whether manganese toxicity secondary to end-state liver disease is associated with nigrastriatal dysfunction as measured by 6-[ ¹⁸F]fluoro-L-DOPA (FDOPA) positron emission tomographic (PET) imaging. Design: Observational case report. Setting: The Movement Disorder Center at Washington University, St Louis, Missouri. Patient: An individual with manganese toxicity secondary to end-stage liver disease. His FDOPA PET was compared with those of 10 idiopathic Parkinson disease patients and 10 age- and sex-matched healthy controls. Main Outcome Measure: The average estimated net FDOPA uptake by Patlak graphical analysis for caudate, anterior putamen, and posterior putamen. Results: The FDOPA uptake for the patient with secondary manganese toxicity was reduced across all regions by more than 2 SDs compared with healthy controls: caudate (reduced 24.7%), anterior putamen (28.0%), and posterior putamen (29.3%). The ratio of uptake between the caudate/posterior putamen was 0.99 and was different from that of idiopathic Parkinson disease patients, in whom the greatest reduction of FDOPA was in the posterior putamen (mean [SD] ratio, 1.65 [0.41]). Conclusions: Reduce striatal uptake of FDOPA uptake indicates dysfunction of the nigrostriatal pathways in manganese toxicity secondary to end-stage liver disease. The pattern of striatal involvement with equal reduction of FDOPAuptake in the caudate compared with posterior putamen appears different from those previously reported in individuals with occupational manganese toxicity and idiopathic Parkinson disease and may be specific to manganese toxicity secondary to end-stage liver disease.