Cryptococcal meningitis is an infection of the meninges (the membranes covering the brain and spinal cord), caused by the fungus Cryptococcus neoformans.

Cryptococcus neoformans is found in soil around the world. Cryptococcal meningitis most often affects people with compromised immune systems. Risk factors include AIDS, lymphoma (a type of cancer), and diabetes. It occurs in 5 out of 1 million people.

• Headache
• Fever
• Nausea and vomiting
• Stiff neck
• Sensitivity to light (photophobia)
• Mental status change
• Hallucinations

In order to diagnose cryptococcal meningitis, a lumbar puncture (spinal tap) must be performed. This test involves taking a sample of fluid from the spinal column (called cerebrospinal fluid or CSF). The following tests on the CSF allow the diagnosis of cryptococcal meningitis:

• CSF stains may show the fungus
• CSF culture grows cryptococcus
• CSF may be positive for cryptococcus antigen

Also, a blood test, the serum cryptococcal antigen test, can be helpful in diagnosing cryptococcus infection, especially in AIDS patients.

Antifungal medications are used to treat this form of meningitis. Intravenous therapy with amphotericin B is the most common treatment. It is often combined with an oral medication, flucytosine. An oral medication, fluconazole, in high doses may also be effective against this infection.

Long-term treatment with medication taken by mouth must be continued for people with AIDS, to prevent the infection from coming back.

Obstructive hydrocephalus is a complication. This occurs when the normal movement of CSF around the brain and spinal cord is disrupted by the infection. The pressure can be relieved with a spinal tap.

Amphotericin B can have severely unpleasant side effects, causing chills and stiffness, and sometimes kidney damage.

Call the local emergency number (such as 911) or go to the emergency room if you have symptoms suggestive of meningitis, or if you are being treated for meningitis and symptoms worsen.

If you have difficulty breathing or swallowing, paralysis, numbness, or sensory or mental state changes, get to the emergency room as quickly as possible.