Tuberculous optochiasmatic arachnoiditis

Arachnoiditis involving optic nerve and the optic chiasm can occur as a complication of tuberculous meningitis (TBM). This study evaluates the clinical features, cerebrospinal fluid (CSF) and laboratory parameters and imaging findings of optochiasmatic arachnoiditis (OCA) and also tried to identify any factors which can predict this complication in patients with TBM. Patients admitted with TBM in the neurology wards of a tertiary care teaching hospital over a period of 6 years formed the material for this study. Student's "t" test and univariate analysis were done to identify any predictors for this complication and the variables found to be significant were further analyzed by multivariate logistic regression analysis. One hundred sixty-three patients with TBM, admitted over a 6-year period, were studied. Twenty-three (14%) patients developed OCA. Eighteen out of 23 (78%) developed this complication while on antituberculous treatment (ATT) and 5/23 (22%) were newly diagnosed cases of TBM. Of those already on treatment, 12/23 (52%) were receiving only ATT, the remaining 6/23 (26%) had received steroids along with ATT in varying doses and duration. The average period from diagnosis of TBM to visual symptoms was 6.4 months. On the multivariate logistic regression analysis, female sex (P < 0.037), age less than 27 (P < 0.008) years and protein content in the CSF > 260 mg% (P < 0.021) were the factors predisposing toward this complication. At 6 months follow-up, on treatment with steroids and ATT, 17% had improvement and no further deterioration was noted in visual acuity in 52%. OCA can develop even while on treatment with ATT. Young women with a high CSF protein content seem to be more prone for this complication.