Chronic meningitis caused by a penicillin-sensitive microorganism?

21 patients studied had persistent or progressive chronic meningitis not associated with a demonstrable infectious or other disease, except Streptococcus milleri antigen in the cerebrospinal fluid of 1 patient. The cerebrospinal-fluid (CSF) abnormalities consisted of a moderate, predominantly mononuclear, pleocytosis, a sharp rise in CSF protein (mean 2.3 g/l), intrathecal synthesis of considerable quantities of oligoclonal immunoglobulin G, and, in half the patients, a fall in the CSF-glucose/blood-glucose ratio. In all patients symptoms began during summer or autumn. In 4 patients the onset was preceded by localised cutaneous lesion, described as erythema chronicum migrans. 4 more patients had been bitten by ticks in the weeks before onset of symptoms. The patients had profound fatigue, malaise, and weight-loss. Half had fever, usually moderate. The neurological abnormalities included aseptic meningitis, cranial neuropathy (mostly facial-nerve paralysis), motor and sensory peripheral radiculoneuropathy, and myelitis. The patients improved or recovered, sometimes dramatically, during a 2-week course of intravenous penicillin G.