Nicolas Nicastro1,2, Pierre R Burkhard3,4, Valentina Garibotto4,5. 1. Department of Psychiatry, University of Cambridge, Cambridge, UK. nicolas.nicastro@hcuge.ch. 2. Division of Neurology, Department of Clinical Neurosciences, Geneva University Hospitals, 4 rue G. Perret-Gentil, 1205, Geneva, Switzerland. nicolas.nicastro@hcuge.ch. 3. Division of Neurology, Department of Clinical Neurosciences, Geneva University Hospitals, 4 rue G. Perret-Gentil, 1205, Geneva, Switzerland. 4. Faculty of Medicine, University of Geneva, Geneva, Switzerland. 5. Department of Nuclear Medicine and Molecular Imaging, Geneva University Hospitals, Geneva, Switzerland.
Abstract
PURPOSE: Scans without evidence of dopaminergic deficit (SWEDD) have been initially described in a minority of subjects with suspected Parkinson's disease (PD). Although a highly controversial entity, longitudinal studies showed that SWEDD cases mostly involve non-degenerative conditions mimicking PD or misattribution of scan images to normal status. Using the Parkinson's Progression Markers Initiative (PPMI) cohort, we undertook a case-controlled analysis of [123I]N-ω-fluoropropyl-2β-carbomethoxy-iodophenyl nortropane ([123I]FP-CIT) single photon emission computed tomography (SPECT) images to measure extrastriatal serotonergic transporter (SERT) density in SWEDD and PD. PROCEDURES: We included 37 SWEDD cases (mean age 60 years, 33 % female) with available [123I]FP-CIT SPECT imaging and high-resolution T1-weighted magnetic resonance imaging (MRI) for coregistration. Sixty-one controls and 62 similarly aged PD subjects were included for group comparisons. Regional [123I]FP-CIT was extracted with PETPVE12 using geometric transfer matrix and partial volume effect correction. RESULTS: PD subjects showed significantly lower [123I]FP-CIT binding in both striatal (caudate nucleus and putamen) and extrastriatal regions (pallidum and insula) compared with controls and SWEDD (all between-group p < 0.0001). PD group also showed lower binding in the thalamus relative to controls (p = 0.007). Receiver operating characteristics (ROC) area under the curve (AUC) did not show a significant difference when using extrastriatal region in addition to striatal ROIs for the separation of SWEDD and PD (95 % ROC-AUC for both methods, p = 0.52). In addition, striatal [123I]FP-CIT binding contralateral to the clinically more affected side was usually lower for PD (> 75 %) but not for SWEDD (< 49 %, p < 0.002). No significant difference regarding [123I]FP-CIT binding was observed between SWEDD and controls. CONCLUSION: These findings corroborate the view that SWEDD cases represent a heterogeneous group of conditions not involving dopaminergic and serotonergic terminals. Further studies are warranted to be assessed whether using extrastriatal [123I]FP-CIT evaluation can be of help in the assessment of degenerative parkinsonism.
PURPOSE: Scans without evidence of dopaminergic deficit (SWEDD) have been initially described in a minority of subjects with suspected Parkinson's disease (PD). Although a highly controversial entity, longitudinal studies showed that SWEDD cases mostly involve non-degenerative conditions mimicking PD or misattribution of scan images to normal status. Using the Parkinson's Progression Markers Initiative (PPMI) cohort, we undertook a case-controlled analysis of [123I]N-ω-fluoropropyl-2β-carbomethoxy-iodophenyl nortropane ([123I]FP-CIT) single photon emission computed tomography (SPECT) images to measure extrastriatal serotonergic transporter (SERT) density in SWEDD and PD. PROCEDURES: We included 37 SWEDD cases (mean age 60 years, 33 % female) with available [123I]FP-CIT SPECT imaging and high-resolution T1-weighted magnetic resonance imaging (MRI) for coregistration. Sixty-one controls and 62 similarly aged PD subjects were included for group comparisons. Regional [123I]FP-CIT was extracted with PETPVE12 using geometric transfer matrix and partial volume effect correction. RESULTS:PD subjects showed significantly lower [123I]FP-CIT binding in both striatal (caudate nucleus and putamen) and extrastriatal regions (pallidum and insula) compared with controls and SWEDD (all between-group p < 0.0001). PD group also showed lower binding in the thalamus relative to controls (p = 0.007). Receiver operating characteristics (ROC) area under the curve (AUC) did not show a significant difference when using extrastriatal region in addition to striatal ROIs for the separation of SWEDD and PD (95 % ROC-AUC for both methods, p = 0.52). In addition, striatal [123I]FP-CIT binding contralateral to the clinically more affected side was usually lower for PD (> 75 %) but not for SWEDD (< 49 %, p < 0.002). No significant difference regarding [123I]FP-CIT binding was observed between SWEDD and controls. CONCLUSION: These findings corroborate the view that SWEDD cases represent a heterogeneous group of conditions not involving dopaminergic and serotonergic terminals. Further studies are warranted to be assessed whether using extrastriatal [123I]FP-CIT evaluation can be of help in the assessment of degenerative parkinsonism.
Authors: A Abi-Dargham; M S Gandelman; G A DeErausquin; Y Zea-Ponce; S S Zoghbi; R M Baldwin; M Laruelle; D S Charney; P B Hoffer; J L Neumeyer; R B Innis Journal: J Nucl Med Date: 1996-07 Impact factor: 10.057
Authors: Manuel Menéndez-González; Francisco Tavares; Nahla Zeidan; José M Salas-Pacheco; Oscar Arias-Carrión Journal: Front Aging Neurosci Date: 2014-04-01 Impact factor: 5.750