A Brief Nonmotor Screen Combined with Transcranial Ultrasound may Improve Diagnostic Accuracy of Parkinson’s Disease

Background: The addition of a simple nonmotor symptom (NMS) screen and transcranial sonography (TCS) to standard clinical assessment may improve the diagnostic accuracy of Parkinson's disease (PD). Methods: Sixty-nine subjects (23 established PD group, 23 healthy controls, and 23 possible PD) were enrolled. All completed 3 “yes-no” NMS questions (score, 0–3) and had a transcranial ultrasound assessing nigral hyperechogenicity (score, 0–1). A combined PD risk score of 0 to 4 was obtained for each subject. A PD risk score of ≥2 was used as the diagnostic cutoff for PD. Results: In the established PD group, there was an average of 2 NMSs per person or a group total of 46 of 69 possible NMSs, but only 4 of 69 NMSs in the healthy control group. Of the technically satisfactory TCS, 16 of 20 (80%) of the established PD group and 2 of 16 (12.5%) of the healthy control group were TCS positive. Using ≥2 NMSs alone as the cutoff identified 17 of 23 (74%) of the established PD and 100% of the healthy controls. The PD risk score of ≥2 identified 21 of 23 (91%) of the established PD as PD and 22 of 23 (96%) of the healthy control group as non-PD. In the possible PD group, the PD risk score identified 9 of 18 (50%) of those with a final clinical diagnosis of PD and 4 of 5 (80%) of non-PD. Conclusions: The combination of a brief NMS screen and TCS discriminated well between normal healthy controls and established PD. A positive TCS and one NMS, or a negative TCS with two NMSs, indicated a likely diagnosis of PD.