Hemodynamic Changes in Rotational Vertebral Artery Syndrome: Diagnostic Role of Dynamic Ultrasound and Identified Thresholds.

Objective: This study evaluated the effectiveness of dynamic ultrasound in diagnosing rotational vertebral artery syndrome (RVAS) and its potential as a screening tool.

Methods: From January 2022 to September 2024, 98 participants (49 suspected RVAS patients and 49 asymptomatic controls) underwent vertebral artery ultrasound in neutral and rotated head positions. Blood flow velocity and resistance index (RI) changes in the V2 and V3 artery segments were compared. Diagnostic performance and compression thresholds were assessed using independent t tests and receiver operating characteristic (ROC) analysis. An additional pilot study group of 10 participants (5 patients with suspected RVAS and 5 asymptomatic controls) was included to assess the diagnostic thresholds and the role of dynamic ultrasound in RVAS detection.

Results: Significant hemodynamic changes were observed in the RVAS group after neck rotation but not in controls. In the V2 segment, velocity decreased from 51.76 ± 14.64 cm/s (neutral) to 44.61 ± 21.01 cm/s (rotated, P = .014). In the V3 segment, velocity increased from 69.37 ± 18.32 cm/s (neutral) to 161.18 ± 51.32 cm/s (rotated, P < .001). RI rose from 0.69 ± 0.06 to 0.76 ± 0.15 (P = .001). ROC analysis identified thresholds of V3 velocity >74.68 cm/s and V3 RI >0.71 for RVAS diagnosis (area under the curve = 0.80, sensitivity = 67.3%, specificity = 85.7%). In the pilot study group, the sensitivity was 80%, and the specificity was 100%.

Conclusion: Dynamic ultrasound effectively detects positional hemodynamic changes and serves as a valuable tool for RVAS diagnosis. Identified thresholds support its clinical utility, advocating broader adoption to improve early detection and management.