Table of Contents
Definition of Meningitis
Inflammation of the meninges, the membranes that surround the brain and spinal cord. Meningitis may result from bacterial, viral, or fungal infection. Viruses are the most common causes of meningitis and can be highly contagious.
Enteroviruses and Haemophilus influenzae type B (Hib) virus are the common viral causes, though many viruses can cause meningitis. Bacterial meningitis may be life threatening and requires immediate treatment with intravenous antibiotic medications. The contagiousness of bacterial meningitis depends on the bacteria.
Symptoms and Diagnostic Path
Symptoms of meningitis tend to be milder with viral meningitis. They may appear gradually and include
- Severe headache
- Nausea and vomiting
- Sore or stiff neck, or inability to touch the chin to the shoulder or chest
- Agitation and confusion
- Inability to remain alert or awake
Lumbar puncture, which may reveal elevated cerebrospinal pressure and evidence of infection such as white blood cells or the presence of bacteria, is the definitive diagnostic procedure.
Treatment Options and Outlook
Bacterial meningitis requires immediate treatment with antibiotic medications. Viral meningitis is self-limiting and usually improves on its own as the illness runs its course. Supportive treatment for viral meningitis may include intravenous fluids to maintain adequate hydration.
Complications that may occur with meningitis regardless of the causative pathogen include swelling of the brain tissue, seizures, and diminished consciousness. With appropriate treatment many people recover fully; some people have residual complications such as cognitive dysfunction, vision impairment, or hearing loss.
Risk Factors and Preventive Measures
The primary risk for meningitis is infection with any virus that can involve the meninges. Meningitis sometimes occurs in clusters of cases in settings where people live in close contact, such as college dormitories. People who are immunocompromised have increased risk for meningitis and many other kinds of infections.
The most effective prevention measures are those that reduce the risk for acquiring viral infections-frequent hand washing and diligent personal hygiene-and early treatment for symptoms of bacterial meningitis.
See also COGNITIVE FUNCTION AND DYSFUNCTION; ENCEPHALITIS; FUNGUS; VIRUS.
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