Tuesday, July 29, 2014

Viral Meningitis

Definition

The word meningitis means any inflammation of the meninges, the membranes filled with blood vessels that cover and protect the spinal cord and brain.

Viral meningitis means the cause is infection with a virus.

Description

Meningitis affects the brain, making it one of the most dangerous of infectious diseases. Infections, medical procedures, accidents, or chemicals can inflame these membranes. Both bacteria and viruses cause meningitis.

When any virus causes meningitis, the result is viral meningitis. Usually the term is used for specific viruses that cause a mild meningitis and no other symptoms or diseases.

Viral meningitis is quite common and a relatively mild illness, when compared to most bacterial meningitis. Some physicians call it aseptic meningitis because bacteria do not grow in the spinal fluid. Because they know that the patient has meningitis but do not know the cause, they say that it is aseptic.

It is spread by direct contact with infected feces or nose and throat secretions. Most children carry the virus without becoming ill. It spreads most rapidly among young children and in any group-living situation where sinks and running water are in short supply. It usually strikes young children in the summer and early autumn. Anyone can get the disease, but most people over 40 are immune.

Causes

Enteroviruses are the usual cause. These are the viruses that only infect human beings and are spread by the fecal-oral route. They live in the human intestine.

Echovirus and Coxsackie are the two that cause most viral meningitis in the U.S.. Polio is also an enterovirus.

Symptoms

Usually viral meningitis starts suddenly. Babies may have a more gradual illness - refusal to eat, sleepier than usual, and fussy. Babies younger than 18 months may develop a rigid or tender back and extreme fussiness that cannot be consoled. Bulging fontanelle (soft spot) occurs less in viral meningitis and, if it does, is usually a late sign.

Some viral meningitis results in a rash that may cover most of the body or just the arms and the legs. The rash is red and flat, though it may be raised in some areas. It is not the same as the rash in meningococcal meningitis, which is small, with pinpoint bright red spots covering most of the body.

Enterovirus meningitis may also cause a sore throat and conjunctivitis.

Most children and adults recover completely within 10 to 14 days. A few children have a long convalescence from viral meningitis. They may have muscle weakness, tiredness, headache, muscle spasms, insomnia, or personality changes such as behavioral problems and inability to concentrate. These are rarely permanent, but may take a few weeks to a few months to disappear.

Diagnosis

Diagnosis is based upon clinical history compatible with meningitis, and a physical exam in which pain is elicited upon flexing the neck. Often a patient with meningitis will have so much pain that the neck will be rigid.

A spinal tap (collecting spinal fluid by means of a small needle inserted into the back) will often demonstrate cells under the microscope compatible with a viral infection.

Treatment

There is no treatment for viral meningitis. The immune system, however, will produce antibodies to destroy the virus.

Until it is known that a child has viral, not bacterial meningitis, he or she will be admitted to the hospital. But once the diagnosis of viral meningitis is made, antibiotics are stopped, and a child who is recovering satisfactorily will be sent home.

Only acetaminophen should be given to reduce fevers. Clear fluids and a bland diet including favorite foods should be offered.

During recovery, a child needs rest in a darkened, quiet room. Bright lights, noise and visitors may irritate a child with meningitis.

Increased pressure on the brain from buildup of fluid in the meninges is a serious complication.

Questions

Is it bacterial or viral meningitis?

Is a lumbar puncture required to rule out bacterial meningitis?

What is the probable cause?

What is the preferred treatment?

Is care at home rather than in the hospital possible?

What are the complications to watch for?

Will there be a complete recovery?