[A case of tuberculous meningitis with pleural effusion as a manifestation of a paradoxical reaction during anti-tuberculosis therapy].

We present a case of tuberculous meningitis (TBM), wherein pleural effusion developed as a manifestation of paradoxical reaction during anti-tuberculosis therapy. An 87-year-old diabetic man was referred to our clinic for fever and impaired consciousness. He did not obey vocal commands. No ocular motor deficit, facial palsy, or limb weakness was observed. He had hyponatremia due to inappropriate antidiuresis. Examination of the cerebrospinal fluid revealed lymphocytosis and high adenosine deaminase (ADA) activity, suggestive of TBM. He was treated with isoniazid, rifampicin, and pyrazinamide, after which his symptoms quickly resolved. Lymphocyte count, ADA activity, and protein concentration in the cerebrospinal fluid decreased. However, approximately 30 days after the initiation of therapy, he developed mild hypoxemia. A chest CT scan revealed pleural effusion. The pleural fluid was exudate with elevated ADA activity, which was consistent with tuberculous pleural effusion. Shortly after the use of a herbal medicine, Goreisan extract, hyponatremia and hypoproteinemia improved, and the pleural effusion was reduced. Approximately one-third of patients with TBM are reported to develop a paradoxical reaction, such as tuberculoma, hydrocephalus, and optochiasmatic and spinal arachnoiditis. The present case suggests that extra-central nervous system manifestations, including pleural effusion, should be considered when treating TBM.