Thwaites’ Diagnostic Scoring and the Prediction of Tuberculous Meningitis

Abstract

Objective: This study was conducted to investigate the applicability of Thwaites’ diagnostic criteria in order to differentiate tuberculous from bacterial meningitis. Material and Methods: The study was done retrospectively in HIV-negative patients (n = 126) with meningitis. Of the 126 patients, 103 had bacterial meningitis and 23 patients had tuberculous meningitis. The diagnosis was confirmed microbiologically in 59 and 12 patients with bacterial and tuberculous meningitis, respectively. The prediction of tuberculous meningitis was determined by Thwaites’ diagnostic scoring using parameters such as age, history of illness, white blood cell count, total cerebrospinal fluid (CSF) white cell count and the percent of neutrophils in CSF. The diagnostic value of the model was assessed by calculating the area under the receiver operating characteristic (ROC) curves. Results: The sensitivity and the specificity of Thwaites’ diagnostic scoring were 95.6% (22/23) and 70.8% (73/103), respectively. In microbiologically proven cases the sensitivity and the specificity were 91.7% (11/12), 79.7% (57/59), respectively. The area under the ROC curve value for the diagnostic scoring was 0.92. Conclusions: Thwaites’ diagnostic score was found to be helpful in differential diagnosis of tuberculous meningitis, however, the usefulness of diagnostic scoring should be validated in large series especially in patients with viral meningitis and low CSF glucose levels.

Clinical Features and Outcome in Adult Cases of Tuberculous Meningitis in Tertiary Care Hospital in Antananarivo, Madagascar

“…TDI allowed differentiating bacterial meningitis from TBM based on 5 criteria weighted by a score including age, duration of symptoms, peripheral blood WCC, CSF WCC, and CSF percentage of neutrophils [9]. Assessment of TDI in different studies including non-HIV adults patients showed sensitivity from 95.6% to 99% and a specificity from 70.8% to 80% [26, 27]. However, specificity is too low when test was applied in high HIV prevalence setting [28].…”

Validation of Thwaites' Diagnostic Scoring System for the Differential Diagnosis of Tuberculous Meningitis and Bacterial Meningitis

“…Thwaites established a scoring system employing 143 cases of TBM and 108 cases of BM by regression analysis; this scoring system was evaluated by Sunbul et al (9) using 23 cases of TBM and 103 cases of BM; their evaluation revealed the sensitivity and specificity of the system to be 95.6z and 70.8z, respectively. The current study showed that the sensitivity of Thwaites' diagnostic scoring system for the differential diagnosis of TBM and BM was 98.2z, but its specificity was only 43.6z, which is much lower compared with previous studies (5,9). Hence, BM patients were divided into initially treated (BM2) and partially treated (BM1) groups according to their intake of antibiotics before admission.…”

A New Diagnostic Scoring for Discrimination of Tuberculous and Bacterial Meningitis on the Basis of Clinical and Laboratory Findings

“…Thwaites’ diagnostic scoring was evaluated in a retrospective study by Sunbul et al [12] who reported sensitivity and specificity rates of 95.8 and 71.6%, respectively. However, in microbiologically proven patients, the sensitivity decreased to 91.7% and the specificity increased to 79.7%.…”