Long-term Meningitis?????

I am writing on behalf of a relative.  He is 69 years old and has had an inflamed meninges now for at least 1 1/2 years.  He was hospitalized 1 year ago with what was thought to be low spinal fluid pressure but tests revealed this wasn't so.  Spinal taps revealed that the pressure was high-normal with no abnormalities. He was placed on prednisone to reduce the inflammation and help with pain.  A variety of tests were performed at the Mayo Clinic including spinal taps last May which concluded in chronic meningtis but no cause was found.  In September he had a biopsy done of the meninges.  Pathology reports from labs in Chicago and at the Mayo Clinic revealed no infection, no fungus and no cancer.  His headaches continue on a daily basis lasting 4-8 hours.  He currently is on 25 mg of prednisone.  We are stymied.  We are currently trying to manage his pain.  We cannot cure the meningitis until we know what the cause is.  Is anyone aware of similar cases?  Someone suggested that we are dealing with the after-effects of meningitis but I am not convinced since the meninges is still inflamed.  Can anyone shed some light on this situation?

[CCF Neuro[P] MD, RPS]

Dear Jerry:

Sorry to hear about your relative.  There are two conditions that look like meningitis, one is pseudotumor cerebri and the other is normal pressure hydrocephalus.  Both would have signs and symptoms of elevated intracranial pressure and negative studies.  Pseudotumor cerebri is treated with either steriods or fluid reducing medications.  NPH or normal pressure hydrocephalus is treated with an initial spinal tap and if a patient gets better than a shunt is placed.  I tell you about these entities because they make more logical medical sense than a sterile meningitis.  However, sometimes if a patient is immunocompromise, a presistent episodic meningitis can occur.  Or recurrent meningitis from a Herpes infection that is exacerbated by stress, or in a chronic illness such as TB a chronic meningitis can occur.  The latter two can usually be diagnosed by analysis of the CSF.  

I would favor the either of the first two of diagnosis.  However, if these have been ruled out, I am not too sure what entity to give your relative.

Sincerely,

CCF Neuro MD