Is Transcranial Sonography Useful to Distinguish Scans Without Evidence of Dopaminergic Deficit Patients From Parkinson’s Disease?

Background: Approximately 10 % of patients clinically diagnosed with early Parkinson’s disease (PD) subse-quently have normal dopaminergic functional imaging. Transcranial sonography (TCS) has been shown to detect midbrain hyperechogenicity in approximately 90 % of Parkinson’s disease (PD) patients and 10 % of the healthy population. The aim of this study was to investigate the prevalence of midbrain hyperechogenic-ity in patients with suspected parkinsonism and scans without evidence of dopaminergic deficit (SWEDD), in comparison to PD patients. Methods: TCS was performed in 14 patients with SWEDD and 19 PD patients. Results: There was a significantly increased area of echogenicity in the PD group (0.24 6 0.06 cm2), com-pared to the group of patients with SWEDD (0.13 6 0.06 cm2; P < 0.001). One (9.1%) of these patients, compared to 14 (82.5%) of the PD patients, was found to have hyperechogenicity (P < 0.001). Conclusions: We conclude that TCS is useful to distin-guish PD patients from patients with suspected parkin