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Pronunciations amphotericin B arachnoid mater azathioprine carbamazepine cerebrospinal fluid coccal coccidioidomycosis computed tomography corticosteroid cryptococcosis cyclosporine cytomegalovirus empyema encephalitis encephalopathy Escherichia coli fluconazole flucytosine immune globulin isoniazid Klebsiella lymphocytic choriomeningitis lymphoma melanoma meninges meningitis meningococcal methotrexate naproxen Neisseria pertussis pneumococcal pneumonia polymerase chain reaction prednisone ranitidine sarcoidosis sepsis Streptococcus pneumoniae subarachnoid subdural T3

Chronic meningitis is a slowly developing inflammation of the subarachnoid space (located within the layers of tissues covering the brain and spinal cord) that lasts a month or longer.

• People may have a fever, a stiff neck, a headache, double vision, or difficulty walking, or they may become confused.
• Imaging of the head and a spinal tap are required for diagnosis.
• Treatment depends on the cause.

The subarachnoid space is located between the middle layer (arachnoid mater) and the thin inner layer (pia mater) of the tissues that cover the brain and spinal cord (meninges—see Biology of the Nervous System: Viewing the Brain).

Chronic meningitis resembles acute bacterial meningitis, but the causes are different and the infection and inflammation develop more slowly, over weeks and months rather than hours and days. If symptoms have been present for a month or more, meningitis is described as chronic.

Causes

Chronic meningitis is usually due to infection, most commonly tuberculosis.

Infectious organisms invade the brain or the subarachnoid space and multiply slowly over weeks or months. Such organisms include the bacteria that cause tuberculosis or syphilis and fungi such as Cryptococcus neoformans or Coccidioides immitis. These fungi are more likely to cause chronic meningitis in people with a weakened immune system, such as those with human immunodeficiency virus (HIV) infection or acquired immunodeficiency syndrome (AIDS).

Acute bacterial meningitis that has been partially treated but not eliminated by antibiotics may evolve into chronic meningitis.

Disorders that are not infections can also cause chronic meningitis. They include sarcoidosis and certain cancers, such as leukemia, lymphoma, brain tumors, and some cancers that spread (metastasize) to the brain from other parts of the body (such as breast or lung cancer).

Chemotherapy drugs that are injected directly into the subarachnoid space (such as methotrexate Some Trade Names
TREXALL
), drugs used to prevent rejection of a transplanted organ (such as cyclosporine Some Trade Names
NEORALSANDIMMUNE
and OKT3), and even nonsteroidal anti-inflammatory drugs (NSAIDs, such as ibuprofen Some Trade Names
ADVILMOTRIN
—see Pain: Nonsteroidal Anti-Inflammatory Drugs) can cause mild to moderate meningitis that lasts days to a few weeks. If treatments are repeated, the meningitis may last longer.

Common Infections That Can Cause Meningitis Organism Comments Bacterial infections Infection with Escherichia coli Newborns, older people, and people with a weakened immune system are affected most often. Meningitis due to these bacteria usually develops after a widespread infection of the blood (sepsis), an infection acquired in a hospital, or surgery on the brain or spinal cord. Infection with Klebsiella bacteria Meningitis due to these bacteria usually develops after sepsis, an infection acquired in a hospital, or surgery on the brain or spinal cord, or in people with a weakened immune system. Infection with Listeria monocytogenes Newborns, people over 50, pregnant women, people with kidney or liver failure or disorders of the immune system, and people who take drugs that affect the immune system are most often affected. These bacteria may be present in unpasteurized milk products and on many butcher's meat counters. Infection withNeisseria meningitides Meningitis due to these bacteria (meningococcal meningitis) is highly contagious and dangerous and causes small epidemics among people living in close quarters. It can cause death within 24 hours. Infection with group B streptococci Newborns are affected most often. Infection with Streptococcus pneumoniae Pneumococcal meningitis occurs more often in infants, alcoholics, and people with ear infections. These bacteria also cause pneumococcal pneumonia, which increases the risk of meningitis. Lyme disease The bacteria that cause Lyme disease are spread by ticks. Lyme disease is common in certain areas of the northeastern United States. Lyme disease can affect the skin, joints, heart, brain, and spinal cord. Rocky Mountain spotted fever The bacteria that cause this infection are transmitted by ticks. The symptoms resemble those of meningitis, but the infection is not meningitis. Syphilis If untreated, syphilis can affect the brain, layers of tissue that cover it (meninges), or both several years after the original infection (or much earlier in people who have HIV infection or AIDS). Tuberculosis Immigrants from areas where tuberculosis is common (such as Asia, Africa, or Latin America), homeless people, and people with HIV infection or AIDS are affected most often. Viral infections Enteroviral infections Enteroviruses are commonly present in the digestive tract and may cause infection when hands are not washed adequately after going to the toilet. Spread among family members is common. Herpes simplex virus type 2 infection This virus causes genital herpes and can cause recurrent episodes of meningitis called Mollaret's meningitis. Human immunodeficiency virus (HIV) infection Meningitis can develop days to weeks after the initial infection. Cytomegalovirus infection In people with HIV infection, this virus can cause a painful meningitis that affects spinal nerves in the lower back. Infectious mononucleosis Rarely, this infection, caused by the Epstein-Barr virus, spreads to the meninges. Mumps Mumps is a common cause of meningitis worldwide but not in the United States because children are routinely vaccinated against it. West Nile virus infection This infection is spread by mosquitoes. Lymphocytic choriomeningitis Most often, this infection results from exposure to dust or food contaminated by waste products from mice and hamsters. Fungal infections Cryptococcosis People with HIV infection, AIDS, or other disorders that weaken the immune system are usually affected. Coccidioidomycosis This infection occurs mostly in the southwestern United States. AIDS = acquired immunodeficiency syndrome; HIV = human immunodeficiency virus.

Some Noninfectious Causes of Meningitis Type Examples Brain disorders Cancer that has spread to the brain from other parts of the body (such as leukemia, lymphoma, melanoma, and breast or lung cancer) Sarcoidosis Behçet's syndrome Craniopharyngioma Drugs that affect the immune system Azathioprine Some Trade Names IMURAN Cyclosporine Some Trade Names NEORALSANDIMMUNE Cytosine arabinoside Intravenous immune globulin OKT3 Nonsteroidal anti-inflammatory drugs (NSAIDs), such as ibuprofen Some Trade Names ADVILMOTRIN , naproxen Some Trade Names ALEVEANAPROXNAPROSYN , sulindac Some Trade Names CLINORIL , and tolmetin Some Trade Names TOLECTIN Other drugs Antibiotics (such as ciprofloxacin Some Trade Names CILOXANCIPRO , isoniazid, penicillin, trimethoprim-sulfamethoxazole Some Trade Names , and other sulfa drugs) Carbamazepine Some Trade Names TEGRETOL Phenazopyridine Some Trade Names PYRIDIUM PLUS Ranitidine Some Trade Names ZANTAC Substances injected into the subarachnoid space* Antibiotics Chemotherapy Dyes used in imaging procedures Anesthetics Vaccines Pertussis (whooping cough) Rabies Smallpox * The space that contains cerebrospinal fluid and is located between layers of tissue covering the brain and spinal cord (meninges).

Symptoms

The symptoms of chronic meningitis are similar to those of acute bacterial meningitis, except that they develop more slowly and gradually, usually over weeks rather than days. Also, fever is often less severe.

Headache, confusion, a stiff neck, and backache are common. People may have difficulty walking. Weakness, pins-and-needles sensations, numbness, facial paralysis, and double vision are also common. Facial paralysis and double vision occur when meningitis affects the cranial nerves (which go directly from the brain to various parts of the head, neck, and trunk).

Diagnosis

Computed tomography (CT) or magnetic resonance imaging (MRI) of the head, followed by a spinal tap (lumbar puncture) with examination of the cerebrospinal fluid, can confirm the diagnosis.

By examining the cerebrospinal fluid, doctors can distinguish between chronic and acute meningitis. In chronic meningitis, the number of white blood cells in the fluid is higher than normal but is usually lower than that in acute bacterial meningitis. Also, the type of white cells is usually different. Some infectious organisms that cause chronic meningitis, such as the fungus Cryptococcus neoformans, are readily visible under a microscope, but many, such as the bacteria that cause tuberculosis, are not.

The cerebrospinal fluid is always sent to a laboratory, where the organism, if present, can be grown (cultured) and identified. However, culturing may take weeks. Special techniques, which may provide results more quickly, may be used to identify fungi and the bacteria that cause tuberculosis and syphilis. For example, the polymerase chain reaction (PCR) technique, which produces many copies of a gene, may identify the unique DNA sequence of the bacteria that cause tuberculosis.

Other tests on cerebrospinal fluid are done, depending on which disorders are suspected. For example, the fluid may be analyzed for cancer cells if metastatic cancer is suspected.

Treatment

The cause of meningitis is treated. For example, chronic meningitis due to sarcoidosis is usually treated with corticosteroids (such as prednisone) for several weeks. Chronic meningitis due to cancer is treated with chemotherapy, radiation therapy, or both. The chemotherapy drug is injected directly into the subarachnoid space through an Ommaya reservoir. This device is implanted under the scalp and delivers the drug slowly, over days or weeks, through a small tube to the spaces around the brain.

Treatment of chronic meningitis due to an infection depends on the organism. Chronic meningitis due to a fungus is usually treated with antifungal drugs given intravenously or by mouth. Amphotericin B Some Trade Names
FUNGIZONE
, flucytosine Some Trade Names
ANCOBON
, and fluconazole Some Trade Names
DIFULCAN
are used most often. When the infection is particularly difficult to cure, amphotericin B Some Trade Names
FUNGIZONE
is sometimes injected directly into the cerebrospinal fluid, either by repeated spinal taps or through an Ommaya reservoir. When chronic meningitis is due to Cryptococcus neoformans amphotericin B Some Trade Names
FUNGIZONE
is usually combined with flucytosine Some Trade Names
ANCOBON
.

Last full review/revision May 2008 by Michael Jacewicz, MD