The value of transcranial Doppler imaging in children with tuberculous meningitis.
OBJECTIVE
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.
Department of Paediatrics and Child Health, Stellenbosch University and Tygerberg Children's Hospital, PO Box 19063, Tygerberg, Cape Town, 7505, Western Cape, South Africa, vtoorn@sun.ac.za.
Ronald
R
van Toorn
H Simon
HS
Schaaf
Regan
R
Solomons
Jacoba A
JA
Laubscher
Johan F
JF
Schoeman
D002648:Child; D005260:Female; D006801:Humans; D019586:Intracranial Hypertension / Q000209:etiology*; D008279:Magnetic Resonance Imaging; D008297:Male; D009169:Mycobacterium tuberculosis / Q000472:pathogenicity; D012189:Retrospective Studies; D013995:Time; D014390:Tuberculosis, Meningeal / Q000000981:diagnostic imaging* / Q000601:surgery; D017585:Ultrasonography, Doppler, Transcranial / Q000009:adverse effects*; D020293:Vasculitis, Central Nervous System / Q000209:etiology*