Transcranial doppler ultrasound clinical and research centers of excellence in sub-Saharan Africa

Nicole, Obrien

Transcranial doppler ultrasound clinical and research centers of excellence in sub-Saharan Africa

Date

2021-12-02

Authors

Nicole, Obrien

Publisher

Kamuzu University of Health Sciences

Abstract

Type of research study: This will be a prospective, multi-center observational study. The problem: There is a critical gap in the neurodiagnostic capabilities on the African continent. Transcranial doppler ultrasound (TCD) is a non-invasive, portable tool that can be used to evaluate the neurovasculature. It may be particularly helpful in various pediatric diseases known to affect the neurovasculature such as sickle cell disease, meningitis, and malaria. However, there are currently no published normative values for TCD flow velocities in African children, limiting its use. The objectives: To determine expected TCD flow velocities in the middle cerebral, posterior cerebral, and basilar arteries of a large cohort of healthy African children of various ages. Methodology: Over a two year period, 150 healthy children will be recruited for participation. Healthy siblings of children with sickle cell disease being cared for at QECH sickle cell clinic will be recruited for participation, as sickle cell trait may impact measured flow velocities. By recruiting these siblings, we should assure that approximately half of the recruited healthy children will have sickle cell trait (Hbg AS) and one quarter will be normal hemoglobin (Hbg AA). This will ensure we are able to determine normative values for all African children. Each recruited participant will undergo a finger prick to check hemoglobin value as well as sickle dex screening. A lab technician is already on site and does venipunctures for every visit of a child with sickle cell disease. The lab technician will also perform the finger sticks for the sickle dex panel in the control patients. They will also undergo a single TCD examination of their main intracranial vessels. A TCD technician, Dr. O’Brien (who lives in Blantyre January-June annually) or Dr. Chagaluka will perform the TCD examinations. Values will be recorded on a paper case report form and then later entered into an electronic database. Expected findings: We expect normative flow velocity values will be similar to slightly higher than previously published values of European children. We believe this is likely to be the case as anemia is more prevalent in this setting and may alter TCD flow velocities. Results will be disseminated to COMREC, throughout the QECH, and locally/regionally/internationally at conferences and in peer reviewed manuscripts.