Meningitis in AdultsMeningitis is a potentially life-threatening infection of the meninges, the tough layer of tissue that surrounds the brain and the spinal cord. If not treated, meningitis can lead to brain swelling bad steroids meningitis cause permanent disability, comaand even death. Meningitis has various causes, including bacterial infection the most serious casesviral infection, fungal infection, reactions to medications, and environmental toxins such as heavy metals. Although bacterial and fungal meningitis require extended hospitalization, meningitis caused by viruses can often be treated at home and has a bad steroids meningitis better outcome. Usually, the brain is protected naturally from the body's immune system by the how to increase the testosterone in body that the meninges create between the bloodstream and the brain itself.
Acute Bacterial Meningitis - Brain, Spinal Cord, and Nerve Disorders - MSD Manual Consumer Version
Find information on medical topics, symptoms, drugs, procedures, news and more, written in everyday language. See also Introduction to Meningitis. 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 space when it is caused by bacteria. Older children and adults develop a stiff neck that makes lowering the chin to the chest difficult or impossible, usually with a fever and headache.
Infants may not develop a stiff neck but may seem generally unwell and have a high or low body temperature, feed poorly, or be irritable or drowsy. Bacterial meningitis is a medical emergency and is treated as soon as possible, before the diagnosis is confirmed. Antibiotics are usually effective if given promptly, and dexamethasone a corticosteroid is often given to reduce swelling in the brain.
The brain and spinal cord are covered by three layers of tissue called meninges. The subarachnoid space is located between the middle layer and the inner layer of the meninges, which cover the brain and spinal cord. This space contains the cerebrospinal fluid, which flows through the meninges, fills the spaces within the brain, and helps cushion the brain and spinal cord. Between the arachnoid membrane and pia mater is the subarachnoid space. This space contains cerebrospinal fluid, which flows through the meninges, fills the spaces within the brain, and helps cushion the brain and spinal cord.
When bacteria invade the meninges and subarachnoid space, the immune system eventually reacts to the invaders, and immune cells gather to defend the body against them. The result is inflammation—meningitis—which can cause complications such as the following:.
If severe, inflammation may spread to blood vessels in the brain and cause clots to form, sometimes resulting in a stroke. Swelling in the brain cerebral edema: Inflammation can damage brain tissue, causing swelling and small areas of bleeding.
Increased pressure within the skull intracranial pressure: Severe swelling can increase pressure within the skull, causing parts of the brain to shift. If these parts are pressed through the small openings in the tissues that separate the brain into compartments, a life-threatening disorder called brain herniation results.
Excess fluid in the brain: The brain continuously produces cerebrospinal fluid. Infection may block it from flowing through the spaces within the brain ventricles and out of the brain. Fluid may accumulate in the ventricles, causing them to enlarge a disorder called hydrocephalus.
As excess fluid accumulates, it can put pressure on the brain. Inflammation of cranial nerves: Inflammation may spread to the cranial nerves , which are involved in sight, hearing, taste, and control of facial muscles and glands.
Inflammation of these nerves may result in deafness, double vision, and other problems. Sometimes pus collects under the outer layer dura mater of the meninges, causing a subdural empyema. These problems include septic shock dangerously low blood pressure due to bacterial infection of the bloodstream and disseminated intravascular coagulation development of small blood clots throughout the bloodstream, eventually leading to excessive bleeding.
These problems can be fatal. Different species of bacteria can cause meningitis. The bacteria most likely to be the cause depends on. Acute bacterial meningitis can develop in infants and children, particularly in geographic areas where children are not vaccinated. As people age, acute bacterial meningitis becomes more common. If meningitis develops within the first 48 hours after birth, it is usually acquired from the mother.
It may be transmitted from mother to newborn as the newborn passes through the birth canal. In these cases, meningitis is often part of a serious bloodstream infection sepsis. Neisseria meningitidis also called meningococci. Streptococcus pneumoniae also called pneumococci. Neisseria meningitidis occasionally causes a rapid, severe infection called meningococcal meningitis, resulting in coma and death within hours.
This infection commonly occurs when bacteria from an upper respiratory infection enter the bloodstream. Meningococcal meningitis is highly contagious. Small epidemics of meningococcal meningitis may occur among people living in close quarters, as occurs in military barracks and college dormitories.
Neisseria meningitidis becomes less common as people age. Haemophilus influenzae type B is now a rare cause of meningitis in the United States and Western Europe because most children are vaccinated against this bacteria. However, in areas where the vaccine is not widely used, these bacteria are a common cause, particularly in children aged 2 months to 6 years. As people age, the immune system weakens, increasing their risk of meningitis due to other bacteria, such as Listeria monocytogenes , E.
In people of all ages, Staphylococcus aureus occasionally causes severe meningitis. When the bacteria spread through the bloodstream from an infection in another part of the body the most common route. When bacteria spread to the meninges from another infection in the head, such as sinusitis or an ear infection often caused by Streptococcus pneumoniae. When a drain shunt , placed in the brain to relieve increased pressure in the skull, becomes infected.
Which bacteria are likely to cause meningitis depends on whether the immune system is normal or weakened. Conditions that can weaken the immune system increase the risk of developing bacterial meningitis. Treatment with corticosteroids or other drugs that suppress the immune system immunosuppressants , which are used to treat autoimmune disorders and cancer or to prevent rejection of a transplanted organ.
Congenital immunodeficiency disorders when children are born with a disorder that weakens the immune system. Which bacteria or fungi are likely to cause meningitis also depends on what is weakening the immune system and which part of the immune system is weakened, as in the following examples:. AIDS or Hodgkin lymphoma: Listeria monocytogenes , the bacteria that cause tuberculosis, or fungi particularly Cryptococcus neoformans.
Problems producing antibodies which help the body fight infection or removal of the spleen: Streptococcus pneumoniae or, less often, Neisseria meningitidis , which may cause a rapid, severe form of meningitis. Recent chemotherapy for cancer: Pseudomonas aeruginosa or gram-negative bacteria such as E. In very young infants particularly premature infants and older people, certain parts of the immune system may be weak, increasing the risk of meningitis due to Listeria monocytogenes.
In newborns and infants, early symptoms usually do not suggest a particular cause. Symptoms most often include. Irritability, such as excessive fussiness or crying that continues or worsens after being comforted and cuddled by the mother or caregiver. Smacking the lips, chewing involuntarily, gazing in different directions, or periodically going limp a type of seizure.
Unlike older people, most newborns and infants do not have a stiff neck. If meningitis becomes severe, the soft spots between skull bones called fontanelles , which are present in infants before their skull bones grow together, may bulge because pressure within the skull is increased. In most children and adults, acute bacterial meningitis begins with symptoms that slowly worsen for 3 to 5 days.
These symptoms may include a general feeling of illness, fever, irritability, and vomiting. Some people have a sore throat, cough, and a runny nose.
These vague symptoms may resemble those of a viral infection. The stiff neck due to meningitis is more than just sore. Trying to lower the chin to the chest causes pain and may be impossible. Moving the head in other directions is not as difficult. However, some people do not have a stiff neck, and some have back pain. As infection progresses, children and adults can become increasingly irritable, confused, and then drowsy.
They may then become unresponsive and require vigorous, physical stimulation to be aroused. This mental state is called stupor. Adults may become seriously ill within 24 hours, and children even sooner. Meningitis may cause coma and death within hours.
Bacterial meningitis is one of the few disorders in which a previously healthy young person may go to sleep with mild symptoms and never awaken. In older children and adults, such a rapid death often results from swelling of the brain. In meningococcal meningitis, the bloodstream and many other organs are often infected. The bloodstream infection called meningococcemia can become severe within hours.
As a result, areas of tissue may die, and bleeding may occur under the skin, causing a reddish purple rash of tiny dots or larger splotches. Bleeding can occur in the digestive tract and other organs.
People may vomit blood, or stool may appear bloody or tarry black. Without treatment, blood pressure drops, leading to shock and death.
Typically, bleeding occurs in the adrenal glands, which shut down, making shock worse. This disorder, called Waterhouse-Friderichsen syndrome, is often fatal unless treated promptly. In some situations, symptoms of bacterial meningitis are much milder than normal, making the disorder more difficult for doctors to recognize. Symptoms are milder when people are being treated with antibiotics for another reason.
For example, they may be being treated for another infection such as an ear or throat infection when meningitis develops, or early meningitis may be mistaken for another infection and be treated with antibiotics. Symptoms can also be milder in people with a weakened immune system due to use of drugs or disorders that suppress the immune system such as AIDS , in alcoholics, and in very old people.
In the very old, the only symptom may be confusion. If bacterial meningitis develops after surgery on the brain or spinal cord, symptoms often take days to develop.