Diagnostic Performance of Transcranial Sonography for Evaluating Substantia Nigra Hyper-echogenicity in Patients with Parkinson's Disease

Abstract

To determine the diagnostic performance of transcranial sonography (TCS) in assessing increased echogenic area of the substantia nigra (SN) in patients with Parkinson's disease (PD). Institutional review board approval was obtained for this retrospective study. A total of 278 PD patients (mean age: 64.7 § 9.8 y, 100 women) and 300 healthy control patients (mean age: 63.6 § 9.3 y, 97 women) were referred for TCS assessment of SN hyper-echogenicity (SN+) from June 2016 to December 2018. Two sonographers independently measured the sizes of the echogenic areas of the SN by TCS imaging in both PD patients and healthy controls. The diagnostic sensitivity, specificity and accuracy of TCS imaging were compared between PD patients and healthy controls. Inter-rater agreement was assessed with the Cohen's k statistic. The sensitivity, specificity and accuracy of readers 1 and 2, respectively, for the identification of SN+ in TCS were 90.3% and 89.6% (251 and 249 of 278), 89.3% and 88.3% (268 and 265 of 300) and 89.8% and 88.9% (519 and 514 of 578). Inter-observer agreement was excellent (k = 0.84). The area under the receiver operating characteristic curve (AUC) for differentiation of PD patients from healthy controls was 0.92 for reader 1 and 0.91 for reader 2. Cutoff values of 0.20 and 0.21 cm 2 were derived from the assessments performed by readers 1 and 2, respectively. We defined 0.20 cm 2 as the optimal cutoff value because it had a higher AUC. TCS is a promising diagnostic technique and can be very helpful in differentiating PD patients from healthy individuals.

A Comprehensive Assessment of Qualitative and Quantitative Prodromal Parkinsonian Features in Carriers of Gaucher Disease—Identifying Those at the Greatest Risk

“…The poorer performance in visual-spatial perception and motor skills and the higher depression scores seen in women compared to men was similar to the general population [ 20 , 21 , 22 ]. The higher hyperechogenicity found in men compared to women has previously been reported by three different groups in China [ 23 , 24 , 25 ]. Whether it is correlated with the higher rate of PD found in males or an actual difference between genders should be further studied.…”

“…Among the tests without age adjustment, we noticed a weak correlation between age with motor skills, MoCA, and smell. Although TCS was shown to be positively correlated to age in healthy controls [ 25 ], it seems that this correlation does not exist with PD patients [ 26 ]. This suggests that the TCS score may be a stable marker in patients with PD throughout the course of the disease [ 12 ].…”

Comparison of Transcranial Sonography and [18F]‐Fluorodopa PET Imaging in GBA1 Mutation Carriers

“…The larger echogenic areas observed in the patients with parkinsonism are consistent with the broader literature describing ultrasonography in PD 27 . Based on a reference cutoff of 20 mm 2 from prior literature, 26 TCS measurements from participants without parkinsonism—including one individual who subsequently developed parkinsonism—were largely in the normal range, whereas most of those with parkinsonism showed abnormally elevated values.…”

“…The larger echogenic areas observed in the patients with parkinsonism are consistent with the broader literature describing ultrasonography in PD. 27 Based on a reference cutoff of 20 mm 2 from prior literature, 26 TCS measurements from participants without parkinsonism-including one individual who subsequently developed parkinsonism-were largely in the normal range, whereas most of those with parkinsonism showed abnormally elevated values. The current data do not rule out a subtle statistical increase in overall mean nigral echogenicity in individuals with GBA1 mutation carriers without parkinsonism relative to healthy genetic controls, as observed in one recent report that did not include post-sonography clinical follow-up 28 ; however, they do suggest a paucity of clinically significant TCS-measured pathology in this group.…”

Comparison between a handheld ultrasound device and a traditional ultrasound for performing transcranial sonography in patients with Parkinson's disease

“…The cutoff obtained was similar to other studies published with traditional machines from var-ious manufacturers and in different countries, given that the majority of the studies worldwide show that an optimal cutoff is between 0.20 and 0.25 cm 2 Vivó-Orti et al (2013). in their research used traditional equipment and found the area of 0.22 cm 2 as a cutoff point in the 90th percentile, and the ROC curve was constructed with 75 subjects with PD and 91 healthy individuals Xu et al (2020),. in their research, made two ROC curves, one for each traditional equipment used to discriminate subjects with PD (n = 278) from healthy individuals (n = 300) to measure SN hyperechogenicity.…”