Transcranial Doppler in children

Abstract

Transcranial Doppler US, a non-invasive tool for evaluating the cerebral arteries, has evolved significantly during the last two decades. This review describes the practical procedure, and summarises and illustrates its established and "work-in-progress" indications in children. Indications for a transcranial Doppler US examination include, but are not limited to: (1) evaluation of cerebral blood flow velocities in the circle of Willis in patients with sickle cell anaemia to guide transfusion therapy; (2) diagnosis and follow-up of vasculopathy, such as moyamoya disease; (3) diagnosis and monitoring of acute cerebrovascular disorders in intensive care patients, in particular following traumatic brain injury, and during cardiovascular surgery; and (4) confirmation of a clinical diagnosis of brain death by documentation of cerebral circulatory arrest.

Long-term treatment follow-up of children with sickle cell disease monitored with abnormal transcranial Doppler velocities

“…In the present study, patients with abnormal velocities in ACA or eICA ($200 cm/s) were also treated with transfusion, contrary to the STOP-1 study wherein only abnormal velocities in MCA and ICA were treated with transfusion. 8 Several reasons justify applying the same prevention for all arteries: normal ACA and eICA velocities are lower than MCA and ICA velocities, 6,10,31 making ACA and eICA velocities $200 cm/s particularly high; high ACA velocities are associated with increased stroke risk 31 ; and high eICA velocities are associated with stenosis and silent stroke risk. 23 Normalization of velocities was observed in 76 of 91 patients (83.5%) placed on transfusion after a mean transfusion duration of 1.4 years.…”

“…These children were screened by TCD imaging (TCDI) 3,[5][6][7] since the age of 12 to 18 months and had a history of abnormal TCDI defined by TAMMV $200 cm/s and at least 1 year of follow-up with TCDI. Hemoglobin levels were measured the same day as the TCDI assessment.…”

Transcranial Doppler ultrasound in therapeutic hypothermia for children after resuscitation

“…The normal values and defined abnormal values for mean flow velocity in the MCA used in this study were summarised in Table 1. 12,13 If the mean flow velocity was different in bilateral MCA, we chose the most severe abnormal mean flow velocity as the severity of this phase.…”

“…A normal PI value has been reported to range from 0.6 to 1.1. 13 We divided the PI level into three categories: low PI (PI < 0.6) indicating hyperaemia, vasospasm or stenosis; normal PI (PI = 0.6-1.1); and high PI (PI > 1.1 including reversal diastolic flow or undetectable flow) indicating increased intracranial hypertension and cerebral asystole (Table 1). If the PI was different in bilateral MCA, we chose the higher PI as the severity of this phase.…”

Pathophysiology and Treatment of Severe Traumatic Brain Injuries in Children

“…Transcranial Doppler (TCD) is a non-invasive examination of the blood flow velocity of the middle cerebral arteries through the transtemporal window (temple anterior to the ear) to determine cerebral hemodynamics and indirectly assess intracranial hypertension (Trabold, Meyer, Blanot, Carli, & Orliaguet, 2004;Verlhac, 2011). The use of TCD to evaluate increased ICP is limited in children (Melo et al, 2011;Meyer et al, 2005) and has previously been used to evaluate cerebral vasospasms (Trabold et al, 2004) and cerebral autoregulation (Vavilala et al, 2004).…”