The value of transcranial Doppler imaging in children with tuberculous meningitis

Abstract

Purpose Transcranial Doppler imaging (TCDI) is potentially a valuable investigational tool in children with tuberculous meningitis (TBM), a condition often complicated by pathology relevant to Doppler imaging such as raised intracranial pressure (ICP) and cerebral vasculopathies. Methods Serial TCDI was performed on 20 TBM children with the aim of investigating cerebrovascular haemodynamics and the relationship between pulsatility index (PI) and ICP. Results We observed a poor correlation between ICP and PI in children with communicating hydrocephalus (p=0.72). No decline in PI was noted following 7 days of medical therapy for communicating hydrocephalus (p=0.78) despite a concomitant decline in ICP. Conversely, a decline in PI was noted in all four children with non-communicating hydrocephalus who underwent cerebrospinal fluid diversion. High blood flow velocities (BFV) in all the basal cerebral arteries were observed in 14 children (70 %). The high BFV persisted for 7 days suggesting stenosis due to vasculitis rather than functional vasospasm. Complete middle cerebral artery (MCA) occlusion, subnormal mean MCA velocities (<40 cm/s) and PIs (<0.4) correlated with radiologically proven large cerebral infarcts. Conclusions TCDI-derived PI is not a reliable indicator of raised ICP in children with tuberculous hydrocephalus. This may be attributed to individual variation of tuberculous vascular disease, possibly compromising cerebral vascular compliance and resistance. Basal artery stenosis secondary to vasculitis is observed during the acute stage of TBM in the majority of children.

Standardized Methods for Enhanced Quality and Comparability of Tuberculous Meningitis Studies

“…This is invasive and only possible during intensive care admission in settings where such facilities exist. Transcranial Doppler [46] and near-infrared spectroscopy provide less-invasive alternatives, but these methods require more rigorous validation and have not yet demonstrated clinical utility. Simple measures to reduce cerebral ischemia and brain cell metabolic stress include maintaining adequate blood pressure and glucose levels, providing supplemental oxygen, and controlling fever [47].…”

Transcranial Doppler Sonography in Patients With Severe Brain Injury

“…These findings are similar to those we demonstrated in a recent study, which compared the transcranial Doppler-derived PI and cerebrospinal fluid opening pressure after lumbar puncture. 5 We also found that a PI of 1.26 or higher was predictive of opening pressures of 20 cm H 2 O or higher (sensitivity, specificity, positive predictive value, negative predictive value, and overall accuracy were 81.1%, 96.3%, 93.8%, 88.1%, and 90.1%, respectively). Although we share the authors' optimism that transcranial Doppler sonography has potential as a monitoring tool in patients with suspected raised intracranial pressure, we wish to highlight some of the factors that may influence transcranial Doppler-derived flow dynamics and how they may affect the design of future studies and possible applications in the field.…”

“…We demonstrated that potential in our recent study, in which we followed the progress of 2 patients with raised intracranial pressure secondary to meningitis and encephalitis. 5 In both cases, changes in intracranial pressure were reflected by changes in the transcranial Doppler-derived PI, yet other patients in the study with similar intracranial pressure measurements had different PI values. In another patient with sinus thrombosis, we also observed a fall in the PI over several weeks, in association with resolution of papilloedema.…”

Transcranial Doppler as a Bedside Evaluation Tool in Tubercular Meningitis: Case Report and Review of Literature

“…used TCD to study blood flow velocities and found high velocities in basal cerebral arteries in 14 children diagnosed with TBM. 7 These high values persisted for 7 days suggesting the cause of elevated velocities to be vasculitis rather than functional vasospasm. Further, in children with non-communicating hydrocephalus, a decline in PI values was noted post CSF diversion procedure.…”