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Johns Hopkins Symptoms and Remedies

Johns Hopkins Medicine

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Meningitis

Between the brain and skull are three protective membranes: the meninges. Swelling due to inflammation of the meninges (meningitis) may exert potentially harmful pressure on the brain.

What is it?

Meningitis is inflammation of the meninges, the three thin layers of tissue that cover the brain. It is almost always due to an infection—usually one that has spread to the meninges from elsewhere in the body. (In rare cases meningitis may also be caused by tumors or exposure to chemical irritants.) Three major types of infections cause meningitis— bacterial, viral, and fungal—and the nature and severity of symptoms vary depending on the specific microorganism involved. For example, viral meningitis (the most common type) typically causes mild symptoms such as headache and malaise and usually gets better on its own in a week or two. On the other hand, bacterial meningitis is a serious medical emergency that may cause brain damage or even be fatal if left untreated. Other types of meningitis (such as those caused by a fungus or tuberculosis) tend to progress slowly but may also lead to brain damage and death if not treated. Immediate treatment should thus be sought even for mild symptoms of meningitis. Prompt diagnosis and treatment allow most people to recover fully, with no permanent neurological damage.

What Causes It?

  • Bacterial, viral, or fungal infection causes meningitis. Meningococcal meningitis (a bacterial variety that is the most dangerous) may occur in epidemic outbreaks.
  • A higher risk of meningitis is associated with head injury, brain surgery, cancer in or around the brain, acute otitis media (middle ear infection), sinusitis, pneumonia, tuberculosis, and alcoholism.
  • Anyone whose immune system is weakened—for example, by AIDS, organ transplantation, or cancer chemotherapy—is at greater risk of meningitis.

Prevention

  • Obtain prompt treatment for bacterial infections elsewhere in the body, especially ear and upper respiratory infections.
  • Vaccines can protect against outbreaks of meningococcal meningitis in groups such as military recruits and hajj pilgrims to Mecca. Travelers to the meningitis belt in sub-Saharan Africa and college freshmen should discuss vaccination with their doctor.
  • Antibiotics may be administered to prevent infection in those who are in close contact with others infected with meningococcal meningitis.

Diagnosis

  • Lumbar puncture (spinal tap) to examine under the microscope spinal fluid for cells and organisms and to culture for bacterial or fungal growth.
  • Blood cultures.
  • CT (computed tomography) scans or MRI (magnetic resonance imaging) may be performed during treatment.

How to Treat It

  • Hospitalization is required for bacterial meningitis. Antibiotics are given in large doses, often intravenously. Corticosteroids may be given to reduce inflammation and tranquilizers may be prescribed to prevent seizures.
  • A respirator may be necessary if the patient loses consciousness.
  • Antibiotics are ineffective against viral meningitis, a form of the disease that is usually mild and is overcome by the body's own defenses within a week or two. Treatment is thus aimed at relieving symptoms: Bed rest, plenty of fluids, and over-the-counter pain relievers are recommended.
  • Antifungal medication is prescribed to treat a fungal infection.
  • Antitubercular medications are given for tubercular meningitis.

When to Call a Doctor

  • EMERGENCY Call a doctor immediately if you or your child develops symptoms of meningitis.