SLC6A3 and Lewy body dementia: The degeneration of the nigrostriatal pathway assessed using the 123iodine FP-CIT SPECT ([123I]FP-CIT SPECT or DAT SPECT) is a well-established in-vivo biomarker for the differentiation of DLB from AD[51], with high accuracy of 86% (sensitivity 80%, specificity 92%) [52].