Hyperechogenicity of the substantia nigra (SN) has been proposed to be a typical finding in Parkinson's disease (PD) and a marker of vulnerability to nigrostriatal dysfunction in healthy subjects. This large cross-sectional study including 1120 subjects older than 50 years without any signs of PD was performed to evaluate the association of SN hyperechogenicity and other proposed epidemiological risk factors for PD. Among all variables assessed only family history of PD and male gender proved to be significantly associated with SN hyperechogenicity, indicating a genetic predisposition for the ultrasound marker.

Transcranial sonography (TCS) is a valuable tool in the diagnosis of Parkinson's disease (PD). However, substantia nigra hyperechogenicity (SN+) in TCS has been shown to be also evident in about 8-10% of healthy persons. Neuroimaging studies and slight motor deficits in subjects with SN+ indicate functional impairment of the nigrostriatal system associated with the ultrasound sign. We questioned, whether SN+ may also be associated with neuropsychological deficits and whether there is a relation to other PD premotor markers. Thirty-six subjects with SN+ and 34 control persons (SN-) older than 50 years were investigated. The delayed verbal memory recall (LogII) of subjects with SN+ was significantly reduced compared to the performance of the control group (P=0.02). Binary logistic regression analysis revealed that, besides UPDRS-III (P<0.001) and positive family history for PD (P<0.01), LogII (P<0.05) seems to be independently associated with SN+.

No abstract