Background: The p.A53T point mutation in the α-synuclein gene (SNCA) is a rare but highly relevant cause of autosomal dominant Parkinson's disease (PD).
Objectives: The objective of this study was to assess striatal dopaminergic denervation in a cohort of symptomatic carriers of the p.A53T SNCA mutation as compared to PD patients.
Methods: Data from the Parkinson's Progression Markers Initiative database of 11 symptomatic p.A53T SNCA mutation carriers who underwent 123I-FP-CIT SPECT [(123) I-2β-carbomethoxy-3β-(4-iodophenyl)-N-(3-fluoropropyl) nortropane single photon emission computed tomography] imaging at our site were compared with those of 33 age-, sex-, and disease duration-matched PD patients.
Results: The p.A53T mutation carriers had significantly lower caudate nucleus binding ratio both contralaterally and ipsilaterally to the most affected side (P = .002 and P = .006) and a decreased contralateral caudate/putamen signal ratio (P = .007) as compared to PD. A similar degree of striatal asymmetry was observed in both subgroups. No correlation between scores in neuropsychological tests and caudate nucleus dopaminergic denervation could be demonstrated.
Conclusions: PD patients harboring the p.A53T SNCA mutation show evidence of a more severe nigrostriatal denervation, especially evident in the caudate nucleus. The lack of significant differences in the putaminal binding ratios may reflect a floor effect or a true preferential targeting of the caudate terminals in p.A53T SNCA-associated PD. © 2018 International Parkinson and Movement Disorder Society.
Keywords: 123I-FP-CIT SPECT; Parkinson's disease; alpha-synuclein; caudate nucleus; neuropsychological tests.
© 2018 International Parkinson and Movement Disorder Society.