Subacute and Chronic Meningitis

Subacute or chronic meningitis is usually caused by an infection. Many microorganisms can cause subacute or chronic meningitis. Among the most important microorganisms are

The bacteria that cause tuberculosis cause a form of chronic meningitis called tuberculous meningitis. Tuberculous meningitis can develop rapidly or gradually. Meningitis may develop when people are first infected. Or the bacteria may remain in the body in an inactive state and become reactivated later and cause meningitis. The bacteria may be reactivated when people are treated with drugs that suppress the immune system (such as tumor necrosis factor inhibitors, including infliximab, adalimumab, golimumab, certolizumab, and etanercept).

Up to 8% of children and some adults with Lyme disease develop meningitis. Meningitis due to Lyme disease may be acute or chronic. Usually, it begins more slowly than acute viral meningitis.

The most common cause of chronic meningitis in the Western hemisphere is

These fungi are more likely to cause meningitis in people who have a weakened immune system Overview of Immunodeficiency Disorders Immunodeficiency disorders involve malfunction of the immune system, resulting in infections that develop and recur more frequently, are more severe, and last longer than usual. Immunodeficiency... read more due to disorders such as human immunodeficiency virus (HIV) infection Human Immunodeficiency Virus (HIV) Infection Human immunodeficiency virus (HIV) infection is a viral infection that progressively destroys certain white blood cells and is treated with antiretroviral medications. If untreated, it can cause... read more or AIDS or who take drugs that suppress the immune system. Symptoms of meningitis due to Cryptococcus neoformans begin gradually and subtly, and they may come and go.

Less commonly, chronic meningitis is caused by the following:

Chronic meningitis is common among people who have HIV infection. Meningitis can result from the HIV infection. But many other organisms (including Cryptococcus neoformans, Mycobacterium tuberculosis, and several fungi) can also cause chronic meningitis in people with HIV infection.

Disorders that are not infections can also cause chronic meningitis. They include

Years ago, a few people developed chronic fungal meningitis after they were given methylprednisolone (a corticosteroid) as an injection into the space around the spinal cord (called an epidural injection) in the lower back (for example, to relieve sciatica). In all cases, the drug had not been prepared using sterile techniques. Symptoms include headache, confusion, nausea, and/or fever. Most people also have a stiff neck, but about one third do not. Symptoms may occur up to 6 months after the injection. If people have any of these symptoms during the weeks or months after having a corticosteroid injection in their back, they should call their doctor.

Occasionally, chronic meningitis persists for months or even years, but no organisms are identified, and death does not result. This type of meningitis is called chronic idiopathic meningitis. Treatment with antifungal drugs or corticosteroids does not help. However, some people with chronic idiopathic meningitis eventually recover without treatment.

The symptoms of subacute or chronic meningitis are similar to those of acute bacterial meningitis Symptoms Acute bacterial meningitis is rapidly developing inflammation of the layers of tissue that cover the brain and spinal cord (meninges) and of the fluid-filled space between the meninges (subarachnoid... read more , except that they develop more slowly and gradually, usually over weeks rather than days. Also, fever is often less severe. Symptoms of chronic meningitis may last for years. Some people get better for a while, then worsen (relapse).

Headache, confusion, a stiff neck, and back pain are common. People may have difficulty walking. Weakness, pins-and-needles sensations, numbness, paralysis of the face, and double vision are also common. Paralysis of the face, double vision, and hearing loss develop when meningitis affects the cranial nerves Overview of the Cranial Nerves Twelve pairs of nerves—the cranial nerves—lead directly from the brain to various parts of the head, neck, and trunk. Some of the cranial nerves are involved in the special senses (such as seeing... read more (which go directly from the brain to various parts of the head, neck, and trunk).

Meningitis due to the bacteria that cause tuberculosis Tuberculosis (TB) Tuberculosis is a chronic contagious infection caused by the airborne bacteria Mycobacterium tuberculosis. It usually affects the lungs, but almost any organ can be involved. Tuberculosis... read more usually worsens fairly rapidly (over days to weeks) but may develop much more rapidly or gradually. Tuberculous meningitis can have serious effects. Pressure within the skull may increase. Blood vessels may become inflamed, sometimes leading to stroke. Vision, hearing, facial muscles, and balance may be affected.

Doctors ask about factors that increase the risk of chronic meningitis, such as a weakened immune system Overview of Immunodeficiency Disorders Immunodeficiency disorders involve malfunction of the immune system, resulting in infections that develop and recur more frequently, are more severe, and last longer than usual. Immunodeficiency... read more (as may be caused by HIV infection or AIDS) and travel to areas where Lyme disease or certain fungal infections are common. Doctors also ask about and look for symptoms that may suggest a cause.

To confirm the diagnosis, doctors do a spinal tap Spinal Tap Diagnostic procedures may be needed to confirm a diagnosis suggested by the medical history and neurologic examination. Imaging tests commonly used to diagnose nervous system (neurologic) disorders... read more (lumbar puncture) to obtain a sample of cerebrospinal fluid, which is then analyzed.

The prognosis for people with subacute or chronic meningitis depends on

Syphilis and Lyme disease usually resolve after treatment. Meningitis due to fungal or parasitic infections is harder to treat and more likely to recur, especially in people with HIV infection.

If meningitis is due to leukemia, lymphoma, or cancer, the prognosis is often poor. In such cases, meningitis can be fatal.

Doctors focus on treating the cause. Depending on the cause, the following treatments are used:

Chronic meningitis due to Cryptococcus neoformans is commonly treated with amphotericin B plus flucytosine or fluconazole. When a fungal infection is particularly difficult to cure, amphotericin B is sometimes injected directly into the cerebrospinal fluid through an Ommaya reservoir. The Ommaya reservoir is a device that is placed under the scalp. The reservoir contains a large supply of drug, which it delivers slowly, over days or weeks, through a small tube running from the reservoir to the spaces within the brain.