Treatment of cerebrospinal fluid leaks and gram-negative bacillary meningitis with large doses of intrathecal amikacin and systemic antibiotics.

Six patients with cerebrospinal fluid (CSF) leaks and gram-negative bacillary meningitis (GNBM) were treated with large doses of intrathecal amikacin (20 to 40 mg daily) and systemic antibiotics. Bactericidal activity was measured in the CSF of each patient, and the dose of intrathecal amikacin was increased if bactericidal activity was absent. Five of six patients had no bactericidal activity with systemic antibiotics alone and/or low dose intrathecal amikacin. All six patients were cured, and three of four patients with vertebral lesions had cessation of CSF leaks within 72 hours of the start of intrathecal amikacin. Intrathecal treatment for 7 to 10 days was adequate for five patients; the CSF of all patients was sterile within 72 hours, and all had a 90% reduction of pleocytosis in the CSF within 96 hours. One patient had radicular back pain after each intrathecal injection, but other side effects were not observed. These findings indicate that CSF leaks associated with GNBM can be effectively treated with large doses of intrathecal amikacin plus systemic antibiotics.