Leptomeningeal and brain biopsy in chronic meningitis

Background: The cause is not found in one third of patients presenting with chronic meningitis. Biopsy of the leptomeninges and brain is often recommended in these patients, but the value of a biopsy is uncertain. Aims: To review the results of leptomeningeal and brain biopsies and their effect on diagnosis and management in patients with chronic meningitis, if the diagnosis was uncertain after clinical assessment, lumbar puncture and radiological investigations. Methods: The clinical features, investigations and the results of leptomeningeal and brain biopsies were reviewed retrospectively in 25 patients presenting with chronic meningitis between 1967 and 1990. Results: The biopsy identified the cause of the chronic meningitis in five patients (neoplastic meningitis in three, tuberculous meningitis in one, granulomatous angiitis in one). In 17 patients the biopsy was abnormal but it did not identify the cause (non-granulomatous lymphocytic meningitis in eight, granulomatous meningitis in two, non-specific abnormalities in seven). In two patients the biopsy was normal and in one patient the tissue was used only for culture. The results of the biopsy led to a beneficial change in treatment in two patients but did not influence management in the other patients. Conclusions: A leptomeningeal and brain biopsy was of limited practical value in diagnosis and management in most patients with chronic meningitis.