Tuberculous meningitis in adults in the terms of tertiary prevention: review of 22 cases.

DEAR EDITOR,

High mortality due to tuberculous meningitis (TM) has been mentioned because of delayed diagnosis and treatment.[12]

A retrospective study was conducted on 22 admitted patients in Loghman Hakim hospital, Tehran, Iran, between October 2005 and August 2009. Tuberculous meningitis is defined as follows. Definite diagnosis of TM with presence of clinical meningitis signs (neck rigidity and abnormal cerebrospinal fluid [CSF] parameter) in addition to acid-fast bacilli or tuberculosis-polymerase chain reaction (TB-PCR) positive in the CSF. Probable TM was considered when clinical meningitis signs were accompanied by at least one of following condition: (1) Suspected active pulmonary tuberculosis based on chest X-ray, (2) acid-fast bacilli found in any sample apart from the CSF, and (3) clinical evidence of other extra pulmonary tuberculosis. Possible TM was considered when clinical meningitis signs accompanied by at least four of the following: (1) A history of predominance of lymphocytes in the CSF, (2) duration of illness more than five days, (3) CSF/blood glucose ratio <0.5, low consciousness, yellow CSF, focal neurological signs, and (4) A good response to anti-tuberculosis chemotherapy.

A total of 18 men and 4 women with a mean age of 29.5 ± 13.5 (18-73) were enrolled. Five (23%) of them were diagnosed with a definite diagnosis, two (9%) with a probable diagnosis, and fifteen (68%) with a possible diagnosis. The length of symptoms before admission, in 21 (95.5%) patients, was five days or more. More than half of the patients revealed neck stiffness, but Kernig and Brudzinski's signs were found at 45.5% and 23% of patients, respectively. Cranial nerve palsy was found in five (23%) patients that two of them (9%) showed VI cranial nerve palsy and three (13.5%) patients were involved by VII cranial nerve palsy. The fever was the most common clinical manifestation (86.5%). Vomiting, anorexia, low consciousness, and seizure were found in 73%, 32%, 41%, and 9%, respectively. Seventeen (77%) patients were discharged from the hospital. Five (23%) patients died and the mortality rate in the first, second, and third week of their admission in the hospital was 2 (9%), 1 (4.5%), and 2 (9%), respectively. Although an effective treatment had been administered for all patients, low consciousness continued in five cases (23%). There was a significant association between the patient's deaths with low consciousness while they were taking anti-tuberculosis treatment and corticosteroid (P < 0.05).

In our study, the mortality rate was 23%. Although 41% of those patients were seriously ill at admission time at the stage III based on Medical Research Council Staging,[3] the mortality rate was lower than Sultas,[4] Verdon,[2] and Cagatay[5] studies (27.8%, 64%, and 43.5%, respectively). Moreover, there was a significant association between the rates of death with low consciousness under taking treatment. This finding was in agreement with Verdon research.[2] Hosoğlu and et al.[1] findings that showed marked alteration in consciousness or coma might predict fatal outcome. In our study, all the deaths occurred within the first three weeks after admission. In Vendor study[2] 70.5% of the patients died within the first three weeks after admission.

TM continues to pose a diagnostic problem. A high index of clinical suspicion is absolutely essential.