title: Regional metabolic changes in parkinsonian patients with normal dopaminergic imaging.
abstract: Dopaminergic imaging has been found to be normal in approximately 15% of parkinsonian patients enrolled in neuroprotective trials. We used (18)F-fluorodeoxyglucose positron emission tomography (FDG PET) to determine the metabolic basis for this finding. We reviewed scans from 185 patients with clinical signs of Parkinson's disease (PD) who underwent (18)F-fluorodopa PET imaging for diagnostic confirmation. Of this group, 27 patients (14.6%) had quantitatively normal scans; 8 of these patients were additionally scanned with FDG PET. Pattern analysis was performed on an individual scan basis to determine whether the metabolic changes were consistent with classic PD. Computer-assisted single-case assessments of the FDG PET scans of these 8 patients did not disclose patterns of regional metabolic change compatible with classical PD or an atypical parkinsonian variant. Similarly, network quantification revealed that PD-related pattern expression was not elevated in these patients as it was in an age- and duration-matched cohort with classical PD (P < 0.0001). None of these patients developed clinical signs of classical PD or of an atypical parkinsonian syndrome at a follow-up visit conducted 3 years after imaging. The results suggest that parkinsonian subjects with normal dopaminergic imaging do not have evidence of classical PD or an atypical parkinsonian syndrome.
authors.affiliation: Center for Neurosciences, Feinstein Institute for Medical Research, North Shore-Long Island Jewish Health System, Manhasset, New York 11030, USA. teckert@nshs.edu
authors.forename: Thomas
authors.initials: T
authors.lastname: Eckert
authors.forename: Andrew
authors.initials: A
authors.lastname: Feigin
authors.forename: Daniel E
authors.initials: DE
authors.lastname: Lewis
authors.forename: Vijay
authors.initials: V
authors.lastname: Dhawan
authors.forename: Steven
authors.initials: S
authors.lastname: Frucht
authors.forename: David
authors.initials: D
authors.lastname: Eidelberg
mesh_terms: D001921:Brain / Q000378:metabolism*; D003342:Corpus Striatum / Q000378:metabolism; D004295:Dihydroxyphenylalanine / Q000031:analogs & derivatives* / Q000493:pharmacokinetics; D004298:Dopamine / Q000378:metabolism* / Q000502:physiology; D005260:Female; D005724:Ganglia / Q000378:metabolism / Q000473:pathology; D006801:Humans; D008297:Male; D008875:Middle Aged; D019578:Multiple System Atrophy / Q000453:epidemiology / Q000378:metabolism; D009778:Occipital Lobe / Q000378:metabolism; D010300:Parkinson Disease / Q000453:epidemiology* / Q000378:metabolism*; D049268:Positron-Emission Tomography; D011699:Putamen / Q000378:metabolism; D012189:Retrospective Studies; D013132:Spinocerebellar Degenerations / Q000453:epidemiology / Q000378:metabolism / Q000473:pathology; D013494:Supranuclear Palsy, Progressive / Q000453:epidemiology / Q000378:metabolism
chemical_list: C043437:fluorodopa F 18; D004295:Dihydroxyphenylalanine; D004298:Dopamine