title: Hyperechogenicity of the substantia nigra in healthy controls is related to MRI changes and to neuronal loss as determined by F-Dopa PET.
abstract: Transcranial ultrasound (TCS) has been shown to reveal hyperechogenicity of the substantia nigra (SN) in Parkinsonian patients and in about 10% of healthy controls. It is hypothesized that SN hyperechogenicity in healthy subjects is a vulnerability marker for idiopathic Parkinson's disease (IPD). Although there is strong evidence that the echomarker results from increased local iron content, the exact pathophysiological mechanisms remain incompletely understood. Thus, prognostic impact can only be estimated. We examined 14 subjects with SN hyperechogenicity (SN+) (7 IPD patients and 7 controls) and 7 healthy controls without the echomarker (SN-) by a magnetic resonance imaging method (MRI; T2 relaxation times) known to reveal tissue inhomogeneity following abnormal iron content and by F-Dopa PET to assess nigrostriatal function.
authors.affiliation: Department of Neurology, University Hospital of the Saarland, Homburg Saar, Germany. s.behnke3@gmx.de
authors.forename: S
authors.initials: S
authors.lastname: Behnke
authors.forename: U
authors.initials: U
authors.lastname: Schroeder
authors.forename: U
authors.initials: U
authors.lastname: Dillmann
authors.forename: H G
authors.initials: HG
authors.lastname: Buchholz
authors.forename: M
authors.initials: M
authors.lastname: Schreckenberger
authors.forename: G
authors.initials: G
authors.lastname: Fuss
authors.forename: W
authors.initials: W
authors.lastname: Reith
authors.forename: D
authors.initials: D
authors.lastname: Berg
authors.forename: C M
authors.initials: CM
authors.lastname: Krick
mesh_terms: D000328:Adult; D004295:Dihydroxyphenylalanine / Q000031:analogs & derivatives*; D004453:Echoencephalography / Q000379:methods*; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009474:Neurons / Q000000981:diagnostic imaging* / Q000473:pathology*; D010300:Parkinson Disease / Q000175:diagnosis*; D049268:Positron-Emission Tomography / Q000379:methods*; D019275:Radiopharmaceuticals; D012016:Reference Values; D013378:Substantia Nigra / Q000000981:diagnostic imaging / Q000473:pathology
chemical_list: D019275:Radiopharmaceuticals; C103149:2,6-difluoro-3,4-dihydroxyphenylalanine; D004295:Dihydroxyphenylalanine