Value of early follow-up CT in paediatric tuberculous meningitis.
BACKGROUND
The value of CT in the diagnosis of tuberculous meningitis (TBM) in children is well reported. Follow-up CT scanning for these patients is, however, not well described and, in particular, the value of early follow-up CT has not been addressed for children with TBM.


OBJECTIVE
To assess the value of early follow-up CT in children with TBM in identifying diagnostic, prognostic and therapeutically relevant features of TBM.


METHODS
A retrospective 4-year review of CT scans performed within 1 week and 1 month of initial CT in children with proven (CSF culture-positive) and probable TBM (CSF profile-positive but culture-negative) and comparison with initial CT for the diagnostic, prognostic and therapeutic CT features of TBM.


RESULTS
The CT scans of 50 children were included (19 "definite" TBM; 31 "probable" TBM). Of these, 30 had CT scans performed within 1 week of the initial CT. On initial CT, 44 patients had basal enhancement. Only 24 patients had contrast medium-enhanced follow-up scans. Important findings include: 8 of 29 patients (who were not shunted) developed new hydrocephalus. New infarcts developed in 24 patients; 45% of those who did not have infarction initially developed new infarcts. Three of the six patients who did not show basal enhancement on initial scans developed this on the follow-up scans, while in seven patients with pre-existing basal enhancement this became more pronounced. Two patients developed hyperdensity in the cisterns on non-contrast medium scans. Eight patients developed a diagnostic triad of features. Three patients developed CT features of TBM where there was none on the initial scans.


CONCLUSIONS
Early follow-up CT is useful in making a diagnosis of TBM by demonstrating features that were not present initially and by demonstrating more sensitive, obvious or additional features of TBM. In addition, follow-up CT is valuable as a prognostic indicator as it demonstrates additional infarcts which may have developed or become more visible since the initial study. Lastly, follow-up CT has therapeutic value in demonstrating hydrocephalus, which may develop over time and may require drainage. We advise routine follow-up CT in patients with suspected TBM within the first week of initial CT and optionally at 1 month.
Andronikou
Savvas
S
Department of Radiology, University of Cape Town, Cape Town, South Africa. docsav@mweb.co.za
Wieselthaler
Nicky
N
Smith
Bruce
B
Douis
Hassan
H
Fieggen
A Graham
AG
van Toorn
Ronald
R
Wilmshurst
Jo
J
D000293:Adolescent; D002544:Cerebral Infarction / Q000000981:diagnostic imaging* / Q000209:etiology / Q000517:prevention & control*; D002648:Child; D002675:Child, Preschool; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D006849:Hydrocephalus / Q000000981:diagnostic imaging* / Q000209:etiology / Q000517:prevention & control*; D007223:Infant; D008297:Male; D011379:Prognosis; D011859:Radiography; D015203:Reproducibility of Results; D012189:Retrospective Studies; D018570:Risk Assessment / Q000379:methods*; D012307:Risk Factors; D012680:Sensitivity and Specificity; D014390:Tuberculosis, Meningeal / Q000150:complications / Q000000981:diagnostic imaging* / Q000628:therapy*