Conversely, a different striatal gradient, with relatively greater caudate involvement, has been observed in patients both with dementia with Lewy bodies (DLB) and Parkinson dementia (PDD) vs. PD, in keeping with the hypothesis that reduced striatal DAT availability in the caudate nucleus is associated with a worse cognitive performance [68,69]. The gene discussed is SLC6A3; the disease is Lewy body dementia.