LRRK2 and Parkinson disease: These results concur with equivalent neuroimaging in vivo analyses in PD patients, in which neuroimaging reductions in DAT striatal density (i.e. by [11C]d-threo-methylphenidate PET or 123I-2β-carbomethoxy-3β-(4-iodophenyl)-N-(3-fluoropropyl)-nortropane SPECT) can be detected at early stages of the disease, including in pre-motor idiopathic REM sleep behavior disorder patients28–30 and pre-symptomatic LRRK2 non-manifesting carriers31–34.