NCT03050567

Reproducibility Study of Transcranial Doppler

Reproducibility Study of Transcranial Doppler Microembolic Signals Detection in the Middle Cerebral Artery

• Status: Completed
• Phase: —
• Study type: Observational
• Enrollment: 40 (actual)
• Sponsor: University of Edinburgh · Academic / Other
• Sex: All
• Age: 18 Years
• Healthy volunteers: Accepted

Summary

Hardening of the neck vessels (carotid arteries) caused by fatty deposits called 'plaques' is a common cause of strokes. Over time plaques can burst or may lead to a severe narrowing (stenosis) of the neck artery. When plaques burst, small clots or fatty particles (called microemboli) break off, block brain vessels and lead to a stroke. Researchers have an incomplete understanding of the processes that cause hardening of the arteries, development of small clots and are unable to predict who will have a stroke. At present, the only ultrasound scan that evaluates circulation in the head and detects these small clots is called the Transcranial Doppler ultrasound. The aim of the study is to test this simple ultrasound technique to see if it can detect signals that may correspond to these small clots or fatty particles. The other objective is to see how repeatable the ultrasound technique is. This may help to identify patients with hardened neck arteries who are at higher risk of a recurrent stroke. This could also potentially improve patients selection to a targeted surgical or future novel pharmacological therapy.

Conditions

• Stroke

Interventions

Type	Name	Description
DIAGNOSTIC_TEST	Transcranial Doppler Ultrasound	Transcranial Doppler will be performed on the symptomatic (ipsilateral to an index event) middle cerebral artery in a quiet temperature controlled room. The middle cerebral artery will be identified through the temporal window in a supine position with a flow direction towards the probe. The subject will have a head frame (Marc 600 Spencer Technologies, USA) fitted to reduce motion and to secure a constant angle of the middle cerebral artery insonation depth at 50-60 mm from the skull surface. All recordings will be made using the ST3 Transcranial Doppler Ultrasound System (Spencer Technologies, USA) with a 2-MHz transducer for 1 hour. Emboli will be detected by listening for their characteristic short audible sound (range 10-100 ms, intensity threshold above 7 dB) and spectral appearance using the International Consensus Group microembolus identification criteria and an automated Embolus Detection Software (Spencer Technologies, USA).

Timeline

• Start date: 2017-03-17
• Primary completion: 2017-08-01
• Completion: 2017-08-09
• First posted: 2017-02-13
• Last updated: 2018-06-25

Locations

1 site across 1 country: United Kingdom