title: Echogenicity of the substantia nigra in relatives of patients with sporadic Parkinson's disease.
abstract: Increased echogenicity of the substantia nigra (SN) on ultrasound is a typical sonographic finding in Parkinson's disease (PD). Sonographic signal intensity of the SN is related to tissue iron content with higher iron level being associated with increased echogenicity. Recent findings indicate that hyperechogenicity of the SN represents an important susceptibility factor for nigrostriatal degeneration. In this study we determined the prevalence of a characteristic ultrasound sign of Parkinson's disease in first-degree relatives of PD patients. Fourteen patients with sporadic PD and 58 of their relatives underwent neurological, neuropsychological, and ultrasound examination. In addition, four pairs of relatives (one member of each pair exhibiting increased echogenicity of the SN and the other with regular SN echogenicity) underwent (18)F-Dopa PET examination. On transcranial sonography, 26 of the 58 relatives exhibited SN hyperechogenicity. Twenty-four relatives showed minor signs of motor slowing. Relatives with SN hyperechogenicity more often showed signs of hypokinesia (16 v 8 relatives; U test, P = 0.01) and impaired executive functions (Tower of London task, problems solved with the minimum number of moves; U test, P = 0.012) than relatives without this echo pattern. In addition, (18)F-Dopa uptake (influx constants) at the putamen was reduced in subjects with SN hyperechogenicity compared to their relatives without this ultrasound sign (Wilcoxon, P = 0.03). In conclusion, approximately 45% of relatives of PD patients exhibited an increased echogenicity of the SN. This sign is associated with clinical findings and objective measurements, indicating some degree of impaired nigrostriatal function.
authors.affiliation: Department of Neurology, Bayerische Julius-Maximilians-Universität, Würzburg, Germany.
authors.forename: Petra
authors.initials: P
authors.lastname: Ruprecht-Dörfler
authors.forename: Daniela
authors.initials: D
authors.lastname: Berg
authors.forename: Oliver
authors.initials: O
authors.lastname: Tucha
authors.forename: Peter
authors.initials: P
authors.lastname: Benz
authors.forename: Michael
authors.initials: M
authors.lastname: Meier-Meitinger
authors.forename: Gesine L
authors.initials: GL
authors.lastname: Alders
authors.forename: Klaus W
authors.initials: KW
authors.lastname: Lange
authors.forename: Georg
authors.initials: G
authors.lastname: Becker
mesh_terms: D000328:Adult; D004295:Dihydroxyphenylalanine; D004292:Dominance, Cerebral / Q000502:physiology; D005260:Female; D005462:Fluorine Radioisotopes; D020022:Genetic Predisposition to Disease / Q000235:genetics*; D005820:Genetic Testing; D006801:Humans; D008297:Male; D008875:Middle Aged; D009410:Nerve Degeneration / Q000000981:diagnostic imaging / Q000235:genetics; D009483:Neuropsychological Tests; D010300:Parkinson Disease / Q000000981:diagnostic imaging / Q000235:genetics*; D011340:Problem Solving / Q000502:physiology; D013378:Substantia Nigra / Q000000981:diagnostic imaging*; D014055:Tomography, Emission-Computed; D017585:Ultrasonography, Doppler, Transcranial
chemical_list: D005462:Fluorine Radioisotopes; D004295:Dihydroxyphenylalanine