Reproducibility Study of Transcranial Doppler

Sponsor

University of Edinburgh (Other)

Overall Status

Completed

CT.gov ID

NCT03050567

Collaborator

(none)

Enrollment

Location

4.8

Actual Duration (Months)

8.4

Patients Per Site Per Month

Study Details

Study Description

Brief 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.

Condition or Disease	Intervention/Treatment	Phase
Stroke	Diagnostic Test: Transcranial Doppler Ultrasound

Study Design

Study Type:

Observational

Actual Enrollment :

40 participants

Observational Model:

Cohort

Time Perspective:

Prospective

Official Title:

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

Actual Study Start Date :

Mar 17, 2017

Actual Primary Completion Date :

Aug 1, 2017

Actual Study Completion Date :

Aug 9, 2017

Arms and Interventions

Arm	Intervention/Treatment
Healthy Volunteers Healthy volunteers with no previous history of cerebrovascular disease and aged over 18 years old.	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).
Subjects with symptomatic carotid artery stenosis Patients with symptomatic cerebrovascular event (stroke, transient ischaemic attack or amaurosis fugax) and image confirmed carotid artery stenosis of >30%. This will include patients scheduled for carotid endarterectomy (>50% for men and >70% for women, by North American Symptomatic Carotid Endarterectomy Trial criteria) or treated conservatively with an optimal medical therapy (if patient declined surgical intervention or is outside surgical criteria for carotid endarterectomy).	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).

Arm

Intervention/Treatment

Healthy Volunteers

Healthy volunteers with no previous history of cerebrovascular disease and aged over 18 years old.

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).

Subjects with symptomatic carotid artery stenosis

Patients with symptomatic cerebrovascular event (stroke, transient ischaemic attack or amaurosis fugax) and image confirmed carotid artery stenosis of >30%. This will include patients scheduled for carotid endarterectomy (>50% for men and >70% for women, by North American Symptomatic Carotid Endarterectomy Trial criteria) or treated conservatively with an optimal medical therapy (if patient declined surgical intervention or is outside surgical criteria for carotid endarterectomy).

Diagnostic Test: Transcranial Doppler Ultrasound

Outcome Measures

Primary Outcome Measures

Presence of microembolic signals in the Middle Cerebral Artery. [14 days]

Eligibility Criteria

Criteria

Ages Eligible for Study:

18 Years and Older

Sexes Eligible for Study:

All

Accepts Healthy Volunteers:

Yes

Inclusion Criteria:

Healthy volunteers with no previous history of cerebrovascular disease and aged over 18 years old.
Patients with symptomatic cerebrovascular event (stroke, transient ischaemic attack or amaurosis fugax) and image confirmed carotid artery stenosis of >30%. This will include patients scheduled for carotid endarterectomy (>50% for men and >70% for women, by North American Symptomatic Carotid Endarterectomy Trial criteria) or treated conservatively with an optimal medical therapy (if patient declined surgical intervention or is outside surgical criteria for carotid endarterectomy).

Exclusion Criteria:

Subjects unable to comply with the study procedures such as a severe disabling stroke.
Inadequate temporal window for Transcranial Doppler assessment.
Adults with incapacity.

Contacts and Locations

Locations

	Site	City	State	Country	Postal Code
1	Centre for Cardiovascular Science	Edinburgh		United Kingdom	EH16 4SB

Sponsors and Collaborators

University of Edinburgh

Investigators

None specified.

Study Documents (Full-Text)

None provided.

More Information

Publications

None provided.

Responsible Party:

University of Edinburgh

ClinicalTrials.gov Identifier:

NCT03050567

Other Study ID Numbers:

AC16131

First Posted:

Feb 13, 2017

Last Update Posted:

Jun 25, 2018

Last Verified:

May 1, 2017

Keywords provided by University of Edinburgh

Microemboli

Study Results

No Results Posted as of Jun 25, 2018