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. Author manuscript; available in PMC: 2021 Apr 1.
Published in final edited form as: Pediatr Blood Cancer. 2020 Jan 11;67(4):e28172. doi: 10.1002/pbc.28172

TABLE 1.

Recommendations for stroke screening in sickle cell anemia and practice patterns in DISPLACE consortium

Practice Recommendations per 2014 NHLBI Guidelines
and STOP Studies (STOP, STOP II, Post STOP)		 Practice Patterns in DISPLACE Consortium
N = 28 (proportion; n)
For children with HbSS and HbSβ0:

  • Screen annually with TCD starting at age 2 up to age 16

 Frequency of TCD Screening:

  • Annually (92.9%; 26)

  • Every 6 months (7.1%; 2)
Method using TCD standard:
  • Highest time-average mean blood-flow velocity in 2-mm increments in the
    • Middle cerebral artery (at three points)
    • Distal internal carotid artery
    • Anterior and posterior cerebral arteries
    • Basilar artery

  • Stroke risk determined from middle cerebral and internal carotid arteries

No clear guidelines for using TCD imaging		 Method of TCD:

  • Dedicated Doppler (57.1%; 16)

  • TCD Imaging (42.9%; 12)

Cerebral vessels examined:

  • Middle cerebral artery (96.4%; 27)

  • Distal internal carotid artery (71.4%; 20)

  • Anterior cerebral artery (71.4%; 20)

  • Posterior cerebral artery (35.7%; 10)

  • Basilar artery (14.3%; 4)

  • Radiologist decides (7.1%; 2)
Abnormal TCD (≥200 cm/sec) in either the middle cerebral artery or the internal carotid artery:

  • Initiate CRCT OR

  • Early repeat of abnormal TCD (within 4 weeks) and initiate CRCT if abnormal confirmed

 Follow-up after abnormal TCD:

  • Initiate CRCT (85.7%; 24)

  • Obtain MRI/MRA (64.3%; 18)

  • Repeat TCD prior to change (28.6%; 8)

  • Initiate hydroxyurea (7.1%; 2)

  • Initiate both CRCT and hydroxyurea (3.6%; 1)
Conditional TCD (170–199 cm/sec)

  • Screen more frequently than annually AND

  • Further increase in screening if:
    • Younger child age
    • TCD velocity closer to 200 cm/sec
 Follow-up after conditional TCD (lower ranges):

  • Repeat TCD prior to change (71.4%; 20)

  • Initiate hydroxyurea (57.1%; 16)

  • Obtain MRI/MRA (32.3%; 11)

  • No change (7.1%; 2)

Follow-up after conditional TCD (higher ranges):

  • Repeat TCD prior to change (96.4%; 27)

  • Initiate hydroxyurea (67.9%; 19)

  • Obtain MRI/MRA (46.4%;13)

  • Initiate CRCT (3.6%; 1)

  • No change (3.6%; 1)
Inadequate TCD (due to technical problems or severe arterial disease with occlusion of the arteries of interest):

  • No clear guideline

  • Repeat TCD or alternative methods of evaluation (e.g., MRA) often performed

 Follow-up after inadequate TCD:

  • Repeat TCD (60.7%; 17)

  • Obtain MRI/MRA (57.1%; 16)

  • Initiate hydroxyurea (7.1%; 2)

  • No change (3.6%; 1)

CRCT = chronic red cell transfusions; DISPLACE = Dissemination and Implementation of Stroke Prevention Looking at the Care Environment

MRA = magnetic resonance angiography; MRI = magnetic resonance imaging; NHLBI = National Heart, Lung, and Blood Institute

STOP = Stroke Prevention Trial in Sickle Cell Anemia; STOP II = Optimizing Primary Stroke Prevention in Sickle Cell Anemia;

TCD = transcranial Doppler