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Meningitis

Inflammation of the meninges (three thin layers of tissue that cover and protect the brain and spinal cord). Meningitis is usually caused by a bacterial or viral infection, but sometimes is caused by cancer, drug allergies, or inflammatory diseases.

PubMed Health Glossary
(Source: NIH - National Cancer Institute)

About Meningitis

Meningitis is most often caused by a bacterial infection. It also may be caused by a virus, fungal infection, parasite, a reaction to certain medications or medical treatments, a rheumatologic disease such as lupus, some types of cancer, or a traumatic injury to the head or spine.

Bacterial meningitis is a rare but potentially fatal disease. It can be caused by several types of bacteria that first cause an upper respiratory tract infection and then travel through the blood stream to the brain. The disease can also occur when certain bacteria invade the meninges directly. The disease can cause stroke, hearing loss, and permanent brain damage.

Pneumococcal meningitis is the most common form of meningitis and is the most serious form of bacterial meningitis. Some 6,000 cases of pneumococcal meningitis are reported in the United States each year....Read more about Meningitis NIH - National Institute of Neurological Disorders and Stroke

What works? Research summarized

Evidence reviews

Bacterial Meningitis and Meningococcal Septicaemia: Management of Bacterial Meningitis and Meningococcal Septicaemia in Children and Young People Younger than 16 Years in Primary and Secondary Care

This guideline covers bacterial meningitis and meningococcal septicaemia, focusing on management of these conditions in children and young people aged younger than 16 years in primary and secondary care, and using evidence of direct relevance to these age groups where available.

Corticosteroids for managing tuberculous meningitis

Tuberculous meningitis is a serious form of tuberculosis affecting the meninges covering the brain and spinal cord. The clinical outcome is poor even when treated with conventional antituberculous drugs. Corticosteroids are commonly used in addition to antituberculous drugs for treating the condition. They help reduce swelling and congestion of the meninges, and thus decrease pressure inside the brain and the attendant risk of death or disabling residual neurological deficit among survivors. This review identified seven trials involving 1140 people that evaluated either dexamethasone or prednisolone given in addition to antituberculous drugs; only one trial was of high quality. Overall, the trials showed that corticosteroids help reduce the risk of death or a risk of death or disabling residual neurological deficit. Only one trial evaluated the effects of corticosteroids in HIV‐positive people, but the effects were unclear. Given the results of the review, all HIV‐negative people with tuberculous meningitis should receive corticosteroids, but more trials are needed in HIV‐positive people.

Corticosteroids for the treatment of parasitic eosinophilic meningitis

Eosinophilic meningitis is an inflammation of the membrane covering the brain, the causes of which can be broadly categorised into infectious and non‐infectious. Among the infectious aetiologies, Angiostrongylus cantonensis, a rat lung worm, is the major cause of eosinophilic meningitis. It occurs principally in South‐East Asia and throughout the Pacific basin. However, this parasite has spread beyond the Pacific basin and is now found in regions of North America due to infected ship rats. Severe headache, which is self limiting, is the main complaint. The headache is probably due to an immune response to the dead parasites. Other signs and symptoms include neck stiffness and pain, visual disturbances, nausea, vomiting, paraesthesia and hyperaesthesia. Corticosteroids are drugs that reduce inflammation, which can occur in eosinophilic meningitis due to dead larvae.

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Summaries for consumers

Corticosteroids for managing tuberculous meningitis

Tuberculous meningitis is a serious form of tuberculosis affecting the meninges covering the brain and spinal cord. The clinical outcome is poor even when treated with conventional antituberculous drugs. Corticosteroids are commonly used in addition to antituberculous drugs for treating the condition. They help reduce swelling and congestion of the meninges, and thus decrease pressure inside the brain and the attendant risk of death or disabling residual neurological deficit among survivors. This review identified seven trials involving 1140 people that evaluated either dexamethasone or prednisolone given in addition to antituberculous drugs; only one trial was of high quality. Overall, the trials showed that corticosteroids help reduce the risk of death or a risk of death or disabling residual neurological deficit. Only one trial evaluated the effects of corticosteroids in HIV‐positive people, but the effects were unclear. Given the results of the review, all HIV‐negative people with tuberculous meningitis should receive corticosteroids, but more trials are needed in HIV‐positive people.

Corticosteroids for the treatment of parasitic eosinophilic meningitis

Eosinophilic meningitis is an inflammation of the membrane covering the brain, the causes of which can be broadly categorised into infectious and non‐infectious. Among the infectious aetiologies, Angiostrongylus cantonensis, a rat lung worm, is the major cause of eosinophilic meningitis. It occurs principally in South‐East Asia and throughout the Pacific basin. However, this parasite has spread beyond the Pacific basin and is now found in regions of North America due to infected ship rats. Severe headache, which is self limiting, is the main complaint. The headache is probably due to an immune response to the dead parasites. Other signs and symptoms include neck stiffness and pain, visual disturbances, nausea, vomiting, paraesthesia and hyperaesthesia. Corticosteroids are drugs that reduce inflammation, which can occur in eosinophilic meningitis due to dead larvae.

Newer, third generation cephalosporins versus conventional antibiotics for treating acute bacterial meningitis

Acute bacterial meningitis is a life‐threatening illness. Currently the evidence suggests that old and new antibiotics offer the same level of treatment. Bacteria which cause meningitis are often thought to be resistant to conventional (older) antibiotics, and so doctors often prescribe newer antibiotics (called third generation cephalosporins). Commencing treatment early is vitally important and the choice of antibiotic is often made without any knowledge of possible drug resistance. This review examined 19 studies with 1496 participants to see whether there is a difference in effectiveness between conventional and newer antibiotics. This review found no differences. Adverse effects in both approaches were similar, except for diarrhoea, which was more common in the cephalosporin group. Only three studies dealt with adults; the remaining studies recruited participants aged 15 years and younger. Therefore, we believe that the results probably pertain more to children. Conventional and newer antibiotics seem reasonable options for initial, immediate treatment. The choice may depend on availability, affordability and local policies.

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Terms to know

Bacterial Meningitis
Inflammation of the membranes surrounding the brain and spinal cord due to a bacterial infection.
Brain
The part of the central nervous system that is contained within the skull (cranium).
Encephalitis
Inflammation of the brain.
Inflammation
Redness, swelling, pain, and/or a feeling of heat in an area of the body. This is a protective reaction to injury, disease, or irritation of the tissues.
Meninges
The three thin layers of tissue that cover and protect the brain and spinal cord.
Spinal Cord
A column of nerve tissue that runs from the base of the skull down the back. It is surrounded by three protective membranes, and is enclosed within the vertebrae (back bones). The spinal cord and the brain make up the central nervous system, and spinal cord nerves carry most messages between the brain and the rest of the body.
Viral Meningitis
Inflammation of the membranes surrounding the brain and spinal cord due to a viral infection.

More about Meningitis

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Other terms to know: See all 7
Bacterial Meningitis, Brain, Encephalitis

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