Keywords: تست الکتروفیزیولوژیک; HRUS; high-resolution ultrasound; BP; brachial plexus; NA; neuralgic amyotrophy; EDx; electrophysiological testing; SSN; suprascapular nerve; CSA; cross-section area; PPV/NPV; positive/negative predictive value; LR; likelihood ratio; OR; odds ratio; AUC;