SLC6A3 and Cognitive impairment: This is not the first study to investigate the relation between non-motor symptoms and striatal DAT availability: olfactory dysfunction and mild cognitive impairment have also been associated with nigrostriatal dopaminergic loss.25,26 However, this is the first study to look at its association with audiological variables assessed by PTA and DPOAEs, further suggesting a possible lateralization effect of cochlear dysfunction, mirroring the course of asymmetric motor impairment.