EVALUATION OF TEMPORAL TAP ON CAROTID ARTERIES DOPPLER WAVEFORM IN NORMAL HEALTHY ADULTS

Abstract

BACKGROUND: Temporal tapping is a validated non-invasive method used during Doppler sonography to differentiate the external carotid artery (ECA) from surrounding branches, the internal carotid artery (ICA) and common carotid artery (CCA). Even though its clinical application is there, not much is known about differential effects of tapping at particular anatomical positions along the superficial temporal artery. OBJECTIVE: To assess the diagnostic utility of temporal tapping at different anatomical points in distinguishing carotid artery waveforms using Doppler ultrasound. METHODOLOGY: This research was of a cross-sectional type. The data was collected from the radiology department of Ali Hospital, Kot Radha Kishen. The study was conducted from December 2024 till March 2025. A total of 196 healthy individuals with normal BMI and no prior history of head & neck surgery were included. Baseline waveforms and rhythmic temporal tapping-induced changes at the proximal and distal sites of the superficial temporal artery were recorded using Doppler ultrasound. Doppler indices of PSV, EDV, RI, and PI of the ECA, ICA, and CCA were recorded. Paired sample t-test was applied for statistical comparison. Data were analyzed using SPSS version 25. RESULTS: The study included 196 healthy adults with 56.6% males (111) and 43.4% females (85). Proximal temporal tapping caused a significant increase in ECA peak systolic velocity (103.6 to 110.15 cm/s) and end-diastolic velocity (29.87 to 30.15 cm/s) (p < 0.001), with minor, non-significant changes in PI and RI. Distal tapping produced smaller, non-significant changes in ECA parameters. No significant changes were observed in CCA and ICA Doppler measurements with either proximal or distal tapping (p > 0.05). These results demonstrate that temporal tapping primarily affects the ECA, confirming its specificity for external carotid artery assessment. CONCLUSION: The study concluded that Proximal temporal tapping induces notable and statistically significant hemodynamic effects on the external carotid artery, thereby highlighting its position as a reliable diagnostic tool for differentiating the ECA from CCA and ICA . The research highlights the importance of site-specific tapping protocols in enhancing the precision and reliability of Doppler-based vascular ultrasound.