Methods: 123 I FP CIT SPECT and neuropathological findings among patients with neurodegenerative syndromes from the Mayo Alzheimer's Disease Research Center and Mayo Clinic Study of Aging were examined. ...The antemortem clinical diagnoses were Alzheimer's disease dementia ADem, N 6 , probable dementia with Lewy bodies pDLB, N 12 , mixed ADem pDLB N 1 , Parkinson's disease with mild cognitive impairment N 2 , corticobasal syndrome N 1 , idiopathic rapid eye movement sleep behavior disorder iRBD N 1 and behavioral variant frontotemporal dementia N 1 . ...