Akinetic‐rigid and tremor‐dominant Parkinson's disease patients show different patterns of FP‐CIT Single photon emission computed tomography

OBJECTIVE: To elucidate whether Parkinson's disease subtypes show a different pattern of Iodine-123 fluoropropyl-;carbomethoxy-3 β-(FP-CIT) single photon emission computed tomography (SPECT) binding in accordance with neuropathological findings. METHODS: We analyzed a database of consecutive patients with FP-CIT scan (n = 190) over a 3-year period and identified 122 patients (50 women, 72 men, mean age 62 ± 11.1 years) with a diagnosis of idiopathic Parkinson's disease. Patient's characteristics and FP-CIT scan results were analyzed and compared for the subgroups tremor-dominant versus akinetic-rigid and equivalent type of Parkinson's disease. RESULTS: The analysis of all Parkinson's disease patients showed a significant difference between the FP-CIT uptake in the subgroups tremor-dominant and akinetic-rigid. After matching these samples for age, disease duration, disease severity (Hoehn & Yahr grade, Unified Parkinson's Disease Rating Scale score), and levodopa-equivalent dose, these findings were balanced between both groups (n = 23/23) without a significant difference (P > 0.05). However, there was a clear, significant association of visually analyzed shapes of the striatum in FP-CIT SPECT and clinical Parkinson's disease subtype. CONCLUSION: These results confirm neuropathological models for a reduced dopaminergic projection to the dorsal putamen in akinetic-rigid patients as well as the lateral putamen and caudate nucleus in tremor-dominant patients in vivo.