Protocol - Stroke Risk in Children with Sickle Cell Disease - TCD

Description

Transcranial Doppler (TCD) ultrasonography is a non-imaging technique that measures the blood flow velocity in large intracranial arteries. This TCD protocol covers how to identify relevant intracranial landmarks and how to record and score TCD results.

Specific Instructions

Results from Transcranial Doppler (TCD) ultrasound should be interpreted by a medical doctor with expertise in TCD in sickle cell disease (SCD). Additionally, the TCD results should be compared with published guidelines to determine if the subject should be receiving prophylactic red cell transfusion or require more frequent TCD or other monitoring.

The Working Group notes that blood-flow velocities indicative of stroke risk can be obtained by either TCD or Imaging Transcranial Doppler (TCDi) ultrasonography. The choice of TCD or TCDi depends on the expertise and equipment available to investigators.

The Sickle Cell Disease Curative Therapy Working Group recommends that transcranial doppler (TCD) ultrasonography be performed in sickle cell patients undergoing hematopoietic cell transplant at one time point pre-transplant. Additionally, investigators should note whether TCD was the indication for the transplant.

Availability

Available

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Protocol

Transcranial Doppler Ultrasonography

Identifying Intracranial Landmarks and Major Cerebral Arteries

Transcranial Doppler (TCD) ultrasonography provides visual landmarks to help correctly identify intracranial blood vessels. Correct identification of intracranial vessels relies on the diameter of the head, position of the transducer, angle of the transducer, depth of the Doppler sample, and direction of the blood flow. In adults, the diameter of the head is assumed to be 130-140 mm, whereas the head diameter must be measured due to variation of children’s head sizes. In children, the bitemporal diameter is measured so that the location of the midline can be calculated (half of the diameter of the head). The internal carotid artery (ICA) bifurcation is the landmark that is the reference point for all other intracranial anatomy. The depth of the ICA bifurcation is estimated to usually be 10 to12 millimeters shallower than the midline.

Recording Transcranial Doppler Ultrasonography Results

The results of the TCD are spectral waveform plots of velocity vs. time and the calculated velocity is the time averaged mean of the maximum velocity. Examiners should record the highest time-averaged mean blood-flow velocity in 2-millimeter increments in the following arteries:

middle cerebral artery (at three points),
distal internal carotid artery,
anterior and posterior cerebral arteries, and
basilar artery.

Scoring

Normal: blood velocities less than 170 centimeters per second in all arteries.

Conditional: blood velocities greater than 170 centimeters per second but less than 200 centimeters per second in all arteries.

Abnormal: blood velocity of 200 centimeters per second or greater in either the internal carotid artery or the middle cerebral artery

Inadequate: if the middle cerebral artery (MCA) velocity cannot be estimated on both sides due to poor signal to noise (S/N) ratio the study is inadequate unless one side shows MCA velocity of greater than or equal to 200 centimeters per second.

Personnel and Training Required

Transcranial Doppler (TCD) ultrasonography should be administered by trained ultrasonographers and interpreted by clinicians (e.g., radiologists, neurologists, hematologists) with expertise in TCD in children with sickle cell disease (SCD).

Equipment Needs

2 megahertz Doppler ultrasonogram

Requirements

Requirement Category	Required
Major equipment	Yes
Specialized training	Yes
Specialized requirements for biospecimen collection	No
Average time of greater than 15 minutes in an unaffected individual	Yes

Mode of Administration

Clinical examination and physical measurement

Lifestage

Toddler, Child, Adolescent

Participants

Children and adolescents aged 2 years and older with hemoglobin SS or beta-zero thalassemia disease and without a history of clinical stroke.

Selection Rationale

Transcranial Doppler (TCD) ultrasound is a non-invasive, valid and reliable method that has been used in clinical trials to select children for prophylactic blood transfusion and as a surrogate end point (stroke risk) in NIH funded clinical trials.

Language

English

Standards

Standard	Name	ID	Source
Human Phenotype Ontology	Sickle Cell Anemia	ORPHA:232	HPO
Human Phenotype Ontology	Anemia	OMIM:603903	HPO
caDSR Form	PhenX PX821001 - Stroke Risk In Children With Sickle Cell Disease Tcd	6254540	caDSR Form

Derived Variables

None

Process and Review

Not applicable.

Protocol Name from Source

Stoke Prevention in Sickle Cell Disease (STOP) Study, Transcranial Doppler (TCD) ultrasonography

Source

Identifying Intracranial Landmarks and Major Cerebral Arteries

Nichols, F. T., Jones, A. M., & Adams, R. J. (2001). Stoke Prevention in Sickle Cell Disease (STOP) Study Guidelines for Transcranial Doppler Testing. Journal of Neuroimaging, 11, 354-362.

Recording and Scoring Results

Adams, R.J., McKie, V.C., Hsu, L., Files, B., Vichinsky, E., Pegelow, C., Abboud, M., Gallagher, D., Kutlar, A., Nichols, F.T., Bonds, D.R., & Brambilla, D. (1998). Prevention of a first stroke by transfusions in children with sickle cell anemia and abnormal results on transcranial Doppler ultrasonography. New England Journal of Medicine, 339(1), 5-11.

General References

Adams, R. J., Brambilla, D. J., McKie, V. C., Hsu, L., Files, B., Vichinsky, E., Pegelow, C., Abboud, M., Woods, G., Olivieri, N., Driscoll, C., Miller, S., Wang, W., Hurlet, A., Scher, C., Berman, B., Carl, E. M., Nichols, F. T., Roach, S., Kutlar, A., Wright, E., Zimmerman, R. A., Gallagher, D., Waclawiw, M., & Bonds, D. (1998). Transfusion Prevents First Stroke In Children with Sickle Cell Disease: The "STOP" Study. New England Journal of Medicine July, 339(1), 5-11.

Adams, R. J. (Principal and Corresponding Author) for the: Optimizing Stoke Prevention in Sickle Cell Anemia Investigative Team (STOP 2). (2005). Discontinuing Prophylactic Transfusion to Prevent Stroke in Sickle Cell Disease. New England Journal of Medicine Dec, 353(26), 2769-2778.

Bulas, D. I., Jones, A., Siebert, J. J., Driscoll, C., O’Donnell, R., & Adams, R. J. (2000). Transcranial Doppler (TCD) screening for stroke prevention in sickle cell anemia: pitfalls in technique variation. Pediatric Radiology 30, 733-738.

Pavlakis, S. G., Rees, R. C., Huang, X., Brown, R. C., Casella, J. F., Iyer, R. V., Kalpatthi, R., Luden, J., Miller, S. T., Rogers, Z. R., Thornburg, C. D., Wang, W. C. & Adams, R. J. (2010). Transcranial doppler ultrasonography (TCD) in infants with sickle cell anemia: Baseline data from the BABY HUG trial. Pediatric Blood Cancer, 54, 256-259.

Platt, O.S. (2005). Preventing stroke in sickle cell anemia. New England Journal of Medicine, 353(26), 2743-2745.

Protocol ID

821001

Variables

Export Variables

Variable Name	Variable ID	Variable Description	dbGaP Mapping
PX821001_StrokeRiskChildrenWithSickleCellDiseaseTCD_Anterior_CerebralArtery
	PX821001090000	Highest time-averaged mean blood-flow more velocity in the anterior cerebral artery show less	N/A
PX821001_StrokeRiskChildrenWithSickleCellDiseaseTCD_BasilarArtery
	PX821001110000	Highest time-averaged mean blood-flow more velocity in the basilar artery show less	N/A
PX821001_StrokeRiskChildrenWithSickleCellDiseaseTCD_Child_Bitemporal_Diameter
	PX821001020000	Child bitemporal diameter	N/A
PX821001_StrokeRiskChildrenWithSickleCellDiseaseTCD_Child_Head_Diameter
	PX821001010000	Child head diameter	N/A
PX821001_StrokeRiskChildrenWithSickleCellDiseaseTCD_Distal_Internal_CarotidArtery
	PX821001080000	Highest time-averaged mean blood-flow more velocity in the distal internal carotid artery show less	N/A
PX821001_StrokeRiskChildrenWithSickleCellDiseaseTCD_Internal_CarotidArtery_Bifurcation_Depth
	PX821001040000	Depth of the internal carotid artery (ICA) more bifurcation show less	N/A
PX821001_StrokeRiskChildrenWithSickleCellDiseaseTCD_Internal_CarotidArtery_Bifurcation_Location
	PX821001030000	Location of the internal carotid artery more (ICA) bifurcation show less	N/A
PX821001_StrokeRiskChildrenWithSickleCellDiseaseTCD_Middle_CerebralArtery_1
	PX821001050000	Highest time-averaged mean blood-flow more velocity in the middle cerebral artery: Point 1 show less	N/A
PX821001_StrokeRiskChildrenWithSickleCellDiseaseTCD_Middle_CerebralArtery_2
	PX821001060000	Highest time-averaged mean blood-flow more velocity in the middle cerebral artery: Point 2 show less	N/A
PX821001_StrokeRiskChildrenWithSickleCellDiseaseTCD_Middle_CerebralArtery_3
	PX821001070000	Highest time-averaged mean blood-flow more velocity in the middle cerebral artery: Point 3 show less	N/A
PX821001_StrokeRiskChildrenWithSickleCellDiseaseTCD_Posterior_CerebralArtery
	PX821001100000	Highest time-averaged mean blood-flow more velocity in the posterior cerebral artery show less	N/A

Neurology, Quality of Life, and Health Services

Measure Name

Stroke Risk in Children with Sickle Cell Disease

Release Date

July 30, 2015

Definition

A clinical test to measure the blood flow velocities in intracranial arteries. Elevated intracranial arterial blood flow rates are indicative of expanding vessel lesions and a subsequent increased risk of stroke.

Purpose

This measure is used to stratify stroke risk in children to determine eligibility for prophylactic blood transfusion for stroke prevention.

Keywords

stroke, Stroke risk, Blood velocity, Transcranial Doppler ultrasonography, TCD, Imaging Transcranial Doppler ultrasonography, TCDi, Brain, Blood flow, "Neurology, quality of life, and Health Services"

Measure Protocols

Protocol ID	Protocol Name
821001	Stroke Risk in Children with Sickle Cell Disease - TCD
821002	Stroke Risk in Children with Sickle Cell Disease - TCDi

Publications

There are no publications listed for this protocol.