Transcranial sonography in atypical parkinsonism: How reliable is it in real clinical practice? A multicentre comprehensive study.

INTRODUCTION: Substantia nigra hyperechogenicity (SN+) in transcranial sonography (TCS) is frequent in Parkinson's disease (PD), while lenticular nucleus hyperechogenicity (LN+) and 3rd ventricle enlargement (3V+) are typical of Atypical Parkinsonisms (AP). However, there are no studies assessing the diagnostic yield of all TCS biomarkers in the three AP (progressive supranuclear palsy, PSP, multiple system atrophy, MSA, corticobasal degeneration, CBD). Previous references lack homogeneous criteria and data are incomprehensive. METHODS: Analysis of TCS performed in routine clinical practice in AP and PD patients from two tertiary hospitals. Expert recommendations were strictly followed. Previous literature was critically analysed. RESULTS: 155 AP (98 PSP, 40 MSA, 14 CBD), 254 PD, 145 control subjects were included. We confirmed good sensitivity for SN+ in PD (80%), but specificity was lower than reported (61%). LN+ and 3V + had moderate sensitivity for AP and PSP diagnosis respectively (65%, 63%), but specificity was higher than reported (87%, 91%). We confirmed high specificity and positive predictive value of the combination SN/LN (98%, 93% AP; 83%, 86% PD). The combinations of two or three echofeatures, previously unreported, showed high specificity but lower sensitivity (SN/3V: 75% sensitivity, 87% specificity PD; 42% sensitivity, 98% specificity PSP) (SN + LN+: 79% sensitivity, 86% specificity CBD) (SN/3V/LN: 67% sensitivity, 89% specificity PD; 29% sensitivity, 99% specificity PSP; 41% sensitivity, 95% specificity MSA; 57% sensitivity 91% specificity CBD). CONCLUSIONS: We present a large comprehensive study of TCS, confirming its usefulness and certain limitations in AP diagnosis. Adherence to consensus criteria is critical to implement TCS for clinical and research purposes.

Quantitative Muscle Ultrasonography Using Textural Analysis in Amyotrophic Lateral Sclerosis.

The purpose of this study was to analyze differences in gray-level co-occurrence matrix (GLCM) parameters, as assessed by muscle ultrasound (MUS), between amyotrophic lateral sclerosis (ALS) patients and healthy controls, and to compare the diagnostic accuracy of these GLCM parameters with first-order MUS parameters (echointensity [EI], echovariation [EV], and muscle thickness [MTh]) in different muscle groups. Twenty-six patients with ALS and 26 healthy subjects underwent bilateral and transverse ultrasound of the biceps/brachialis, forearm flexor, quadriceps femoris, and tibialis anterior muscle groups. MTh was measured with electronic calipers, and EI, EV, and GLCM were obtained using Image J (v.1.48) software. Sensitivity, specificity, likelihood ratios, and area under the curve (AUC) were performed by logistic regression models and receiver operating characteristic curves. GLCM parameters showed reduced granularity in the muscles of ALS patients compared with the controls. Regarding the discrimination capacity, the best single diagnostic parameter in forearm flexors and quadriceps was GLCM and in biceps brachialis and tibialis anterior was EV. The respective combination of these two parameters with MTh resulted in the best AUC (over 90% in all muscle groups and close to the maximum combination model). The use of new textural parameters (EV and GLCM) combined with usual quantitative MUS variables is a promising biomarker in ALS.