Effect of Age on Substantia Nigra Hyper-echogenicity in Parkinson's Disease Patients and Healthy Controls.

Substantia nigra (SN) hyper-echogenicity (SN+) describes an enlargement (>90th percentile) of the area of echogenicity at the anatomic site of the SN in the midbrain detected by transcranial sonography. This ultrasound sign has proven to be a valuable marker supporting the clinical diagnosis of Parkinson's disease (PD). Although there is considerable variation in the extent of echogenic signals at the anatomic site of the SN among PD patients, previous work suggests that SN+ is a stable marker throughout the course of the disease.

Substantia Nigra Hyperechogenicity: Validation of Transcranial Sonography for Parkinson Disease Diagnosis in a Large Estonian Cohort.

Objectives: Substantia nigra hyperechogenicity is a promising biomarker for Parkinson disease (PD). Substantia nigra hyperechogenicity has previously been established as a useful diagnostic criterion in several European and Asian patient cohorts. However, diagnostic cutoff values for substantia nigra hyperechogenicity remain unknown for most patient populations.