Like all other diseases of the human body, meningitis exists along a spectrum.
[ Acute meningitis –> Subacute meningitis –> Chronic meningitis ]
Somewhere in the middle, squished between subacute and chronic meningitis, is Recurrent Meningitis. And maybe this accounts for 2-3% of all cases of meningitis, at least the ones that come to clinical attention, but that doesn’t mean you won’t see it. The patient with acute meningitis may have a recent fever, headache, or neck pain. There could be cranial neuropathies, double vision, or facial weakness. Sometimes your patient will look really sick, as if they are having their worst headache of life and may be vomiting from intracranial hypertension. In other patients, symptoms may be very subtle. Malaise. Or chills. And when you get the lumbar puncture or even the MRI of the brain, then you know. It’s meningitis. In this week’s episode of BrainWaves, Dr. Jon Rosenberg discusses his experience and recent paper on recurrent meningitis.
According to Dr. Rosenberg, recurrent meningitis is defined as at least two episodes of headache, fever, and meningismus with associated cerebrospinal fluid (CSF) pleocytosis, separated by a period of full recovery. Recurrent meningitis typically presents as aseptic meningitis, while recurrent bacterial meningitis is usually the result of a predisposing anatomic defect or immunocompromised state.
There are 5 major disease categories when you think about the causes of recurrent meningitis (in no particular order):
1. Benign tumors (craniopharyngiomas, epidermoid tumors, dermoid tumors)
2. Malignant tumors (leptomeningeal carcinomatosis)
3. Drug-induced meningitis (NSAIDs, IV Ig, anti-epileptics, anti-neoplastics)
4. Infections (viral or bacterial)
5. Autoimmune conditions (Behcet’s, lupus, sarcoidosis, Sjogren’s)
As Dr. Rosenberg says in the episode, the devil is in the details. No exam technique or MRI (right) is going to tell you the diagnosis. Besides targeted testing, which could include over 100 unique serologic and CSF assays, your history and exam are fundamental to the workup of this patient with headache. While obtaining the history, you’re wondering if the patient has any personal or family history of autoimmune conditions, known viral exposures, or history of cancer or something that might make you think cancer. What medications were they taking? (Almost any can cause headache…) Does your patient have any unusual physical exam findings, any palpable lymphadenopathy, evidence of melanoma, or abdominal masses? What hints can you abstract from a detailed history and physical exam?
Once you’ve identified the cause, you can narrow your treatment. Often these patients will present with an acute septic or aseptic meningitis, and they will be immediately covered with broad-spectrum antibiotics. Moving through your five major categories, let’s start with a benign tumor of the central nervous system. Invariably a craniopharyngioma or epidermoid tumor which causes meningitis will be surgically removed, with rare exceptions. In malignant tumors, median survival is a matter of months for most cancers that spread to the leptomeninges. The odds of a favorable outcome are better for some of the hematologic malignancies which can metastasize at the time of diagnosis. In drug-induced meningitis, which may be the most common form of recurrent aseptic meningitis, the offending medication should be immediately and irreversibly discontinued. Unfortunately, much of the time, you might not know what this drug is! So look for the common culprits, and remove them first. For recurrent infectious causes, usually HSV2, there is no evidence that antivirals do anything in these instances, and treatment is often supportive. In recurrent bacterial meningitis, treatment consists of correcting the underlying immune deficiency or anatomic defect responsible for permitting the organism to remain in the CSF. Autoimmune conditions are often managed with corticosteroids, and patients should be ultimately weaned onto steroid-sparing agents. [These are not my recommendations, I am summarizing expert opinions.]
For more information on the subtleties of this clinical condition, I’ll refer you to the podcast from this week. Also worth checking out are other episodes on Aseptic Meningitis and the Basics of CSF Interpretation.
BrainWaves’ podcasts and online content are intended for medical education only and should not be used for routine clinical purposes. Please don’t LP every patient with migraine. That’s just mean.
- Rosenberg J and Galen BT. Recurrent Meningitis. Curr Pain Headache Rep. 2017;21:33.
- Zunt JR and Baldwin KJ. Chronic and subacute meningitis. Continuum (Minneap Minn). 2012;18:1290-318.