The challenge of differentiating tuberculous meningitis from bacterial meningitis

Tuberculous meningitis (TBM) is a rare but important differential diagnosis in patients with impaired consciousness. Here, we describe a case of TBM in an 83-year-old Japanese woman who presented to a local hospital with fever and decreased consciousness of 20 days' duration (from day -40). She was started on treatment for bacterial meningitis due to an increased cerebrospinal fluid cell count, but her condition did not improve. She was transferred to a second hospital on suspicion for cholecystitis, then to a university hospital when consciousness did not improve and finally to us at a fourth hospital. On day -2, diffuse granulation was seen in both lung fields on chest computed tomography, sputum Mycobacterium test was positive and adenosine deaminase was elevated in spinal fluid. We diagnosed TBM secondary to miliary tuberculosis and started treatment with steroids and anti-tuberculous drugs (day 0). However, her level of consciousness did not improve and she died at a sanatorium on day 178. Delayed treatment of TBM has a prognostic impact and should be kept in mind as a differential diagnosis for impaired consciousness.