Assessment of Transverse-sigmoid Sinus Dural Arteriovenous Fistula using Transcranial Doppler Ultrasonography: A Case Report.

BACKGROUND: The most common symptoms of transverse-sigmoid sinus dural arteriovenous fistula (TS-S DAVF) are pulsatile tinnitus and headache. The clinical characteristics lack specificity and may lead to misdiagnosis or delayed diagnosis. The noninvasive and convenient nature of neurovascular ultrasound has made it an important screening tool for lesions. This paper reports the use of transcranial Doppler (TCD) ultrasonography for the preoperative screening and postoperative follow-up of a patient diagnosed with a transverse-sigmoid sinus dural arteriovenous fistula (TS-S DAVF). CASE PRESENTATION: A 62-year-old lady was admitted with a six-month history of headache and tinnitus on the left side. A structured TCD-based approach was used to evaluate intracranial and extracranial hemodynamics. The protocol included targeted probe positioning based on anatomical landmarks, spectral waveform analysis, and the superficial temporal artery tap maneuver. The preoperative TCD results indicated hemodynamic alterations with increased flow and decreased resistance in the left common carotid artery, external carotid artery, and occipital artery. The presence of a Cognard Type III DAVF in the left transverse sinus-sigmoid sinus was confirmed through DSA. The occipital artery and the posterior branch of the middle meningeal artery were the key feeding arteries with cortical vein drainage to the sigmoid sinus. After endovascular embolization via the venous approach, follow-up TCD showed normal hemodynamics in the previously affected arteries, consistent with complete resolution of the patient's clinical symptoms. CONCLUSION: A structured TCD-based approach may help identify shunt-related hemodynamic abnormalities in suspected TS-S DAVF and support postembolization follow-up. Cerebral DSA remains necessary for definitive diagnosis and treatment planning.