Shunt surgery in poor grade patients with tuberculous meningitis and hydrocephalus: effects of response to external ventricular drainage and other variables on long term outcome.

Thirty two poor grade patients (grade 3, 20 patients and grade 4, 12 patients) with tuberculous meningitis and hydrocephalus were prospectively studied to evaluate the response to external ventricular drainage in predicting outcome after shunt surgery. All grade 3 patients underwent a shunt procedure irrespective of their response to external ventricular drainage, and an attempt was made to correlate the immediate response to external ventricular drainage to their long term outcome. Patients in grade 4 underwent shunt surgery only if there was clinical improvement by at least one grade after external ventricular drainage. Follow up (mean 23.1 months) was available for 30 patients (93%). Of the 20 patients in grade 3, seven underwent shunt surgery directly, 13 after an external ventricular drainage. In the group which underwent drainage, the immediate clinical response was improvement in six, no change in six, and death in one. Long term improvement or death occurred almost equally in all the subgroups. The immediate response to external ventricular drainage was not predictive of the long term outcome in grade 3 patients. All 12 patients in grade 4 underwent an external ventricular drainage and only one improved. The rest continued to deteriorate and succumbed to the disease. Grade at admission was the single most important predictor of good outcome (p=0.002) and severity of hydrocephalus had an adverse impact on outcome (p=0.04). The rest of the variables studied (age, duration of illness, duration of altered sensorium, CSF cell count, and CSF protein concentrations) had no effect on long term outcome. All patients in grade 3 should be given the benefit of shunt surgery without a trial of external ventricular drainage. However, patients in grade 4 should undergo an external ventricular drainage in view of the high mortality in this group.