Idiopathic steroid responsive chronic lymphocytic meningitis - clinical features and long term outcome in 17 patients

Background: Some patients with chronic lymphocytic meningitis appear to res pond to corticosteroid treatment, but, investigations fail to identify the cause. The use of corticosteroids in patients with chronic meningitis is co ntroversial and the long term outcome is unclear. Aim: To review the long term outcome in 17 patients with the syndrome of id iopathic steroid responsive chronic lymphocytic meningitis. Methods: Review of patients' records and examination of surviving patients 1.5 to 17.5 years (median 8.8 years) after presentation. Results: The cause of the steroid responsive chronic meningitis was found d uring follow up in two of the 17 patients: Wegener's granulomatosis and mul tiple sclerosis in one patient each. A cause was not found in the other 15 patients. Seven of those patients eventually recovered and corticosteroids were withdrawn after six weeks to six years without a recurrence of symptom s. Four patients improved transiently, but died six months to 26 years afte r starting treatment; in two, steroids were withdrawn a few weeks before de ath. Four patients had active chronic meningitis and reduction in the dose of corticosteroids was associated with a recurrence of symptoms. Leptomenin geal and brain biopsy in eight patients showed non-specific abnormalities w hich were not helpful in the diagnosis. Conclusions: A subgroup of patients with idiopathic chronic lymphocytic men ingitis responds to corticosteroids. Leptomeningeal biopsy and long term fo llow up seldom identify the underlying cause in these patients. Steroid tre atment must be undertaken with caution, even after infective causes of chro nic meningitis have been excluded.