Encephalitis
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Encephalitis and meningitis are inflammatory
diseases of the membranes that surround the brain and spinal cord
and are caused by bacterial or viral infections. Viral meningitis is
sometimes called aseptic meningitis to indicate it is not the result
of bacterial infection and cannot be treated with antibiotics.
Symptoms of encephalitis include sudden fever, headache, vomiting,
heightened sensitivity to light, stiff neck and back, confusion and
impaired judgment, drowsiness, weak muscles, a clumsy and unsteady
gait, and irritability. Symptoms that might require emergency
treatment include loss of consciousness, seizures, muscle weakness,
or sudden severe dementia.
Symptoms of meningitis, which may appear suddenly, often include
high fever, severe and persistent headache, stiff neck, nausea, and
vomiting. Changes in behavior such as confusion, sleepiness, and
difficulty waking up may also occur. In infants, symptoms of
meningitis may include irritability or fatigue, lack of appetite,
and fever. Viral meningitis usually resolves in 10 days or less, but
other types of meningitis can be deadly if not treated promptly.
Anyone experiencing symptoms of meningitis or encephalitis should
see a doctor immediately.
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Antiviral medications may be prescribed for herpes
encephalitis or other severe viral infections. Antibiotics may be
prescribed for bacterial infections. Anticonvulsants are used to
prevent or treat seizures. Corticosteroids are used to reduce brain
swelling and inflammation. Sedatives may be needed for irritability
or restlessness. Over-the-counter medications may be used for fever
and headache. Individuals with encephalitis or bacterial meningitis
are usually hospitalized for treatment.
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The prognosis for encephalitis varies. Some cases
are mild, short and relatively benign and patients have full
recovery. Other cases are severe, and permanent impairment or death
is possible. The acute phase of encephalitis may last for 1 to 2
weeks, with gradual or sudden resolution of fever and neurological
symptoms. Neurological symptoms may require many months before full
recovery. With early diagnosis and prompt treatment, most patients
recover from meningitis. However, in some cases, the disease
progresses so rapidly that death occurs during the first 48 hours,
despite early treatment.
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The NINDS supports and conducts research on infections
and diseases of the brain and nervous system including encephalitis
and meningitis. Much of this research is aimed at learning more
about the cause(s), prevention, and treatment of these disorders.
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Meningitis Foundation of America,
Inc.
National Meningitis Association
National Institute of Allergy and Infectious
Diseases (NIAID)
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