Enlarged hyperechogenic substantia nigra is related to motor performance and olfaction in the elderly

Department of Neurology, University Hospital, Homburg Saar, GermanyAbstract: Enlarged substantia nigra hyperechogenicity(SNþ) assessed by transcranial sonography (TCS) may beassociated with Parkinson’s disease (PD) risk markers suchas impaired motor performance and hyposmia. The aim ofthis multicenter cross-sectional study was to define the asso-ciation between SNþ and these risk markers in a large popu-lation older than 50 years without the diagnosis of PD. Inthree centers (Tuebingen, Homburg, and Innsbruck), 1,839individuals were examined. The echostatus of the SN wasassessed by TCS, motor performance by the Unified Parkin-son’s Disease Rating Scale (UPDRS) motor score, and olfac-tory function with Sniffin’ Sticks. From the 1,603 subjectsincluded in the analysis, 16.2% were SNþ, 23.0% scoredabove zero in the UPDRS motor section, and 28.0% werehyposmic as defined by less than 75% correctly classifiedSniffin’ Sticks. SNþ was associated with a UPDRS motorscore above zero (OR 1.45, 95% CI 1.08–1.96) and with alower odor identification capability (OR 1.48, 95% CI 1.12–1.96). The combination of these two features (OR 1.98, 95%CI 1.25–3.15) and UPDRS motor scores 3 lead to higherOR. It is concluded that SNþ, impaired motor performance,and hyposmia are frequently observed in the elderly and inisolation are unspecific and of limited use to predict a sub-ject’s risk for PD. Whether the association of SNþ with bothimpaired motor performance and hyposmia as seen in thisstudy predicts an increased risk for the development of PDneeds to be evaluated in the follow-up inves-tigations. 2010 Movement Disorder SocietyKey words: cohort studies; Parkinson’s disease/parkinson-ism; ultrasound