:: encephalitis

Encephalitis comes from the Greek enkephalos meaning brain and itis meaning inflammation. The effects of Encephalitis can range in severity from having little or no long term results to being life-threatening. Children and adults of both sexes and all ethnic groups can be affected at any age. It is thought that the annual incidence in the UK and Republic of Ireland is 4 per 100,000 or 2,500 people per year.

Click to enlarge

Encephalitis is usually caused by a viral infection. Exposure to viruses can occur through insect bites, food or drink contamination, inhalation of respiratory droplets from an infected person, or skin contact. Common illnesses such as measles and mumps can lead to Encephalitis. The virus reaches the brain causing an infection. Infected nerves may become damaged or destroyed. Although viruses infecting the brain are a major cause of encephalitis, the body’s reaction to a virus itself can lead to encephalitis. This occurs when the immune system tries to fight off the virus and by mistake, attacks the nerves in the brain at the same time. This condition is called Post Infectious or autoimmune Encephalitis.

Symptoms of Encephalitis include:
· Fever or flu-like illness
· Headache
· Vomiting
· Light-sensitivity of the eyes
· Stiff neck and back (occasionally)
· Confusion, disorientation
· Behaviour that is out of character,
· Drowsiness
· Clumsiness, unsteady gait

More serious acute symptoms that require immediate investigation include:
· Loss of consciousness, poor responsiveness, stupor, coma
· Seizures
· Muscle weakness or paralysis

A diagnosis of Encephalitis is made following a range of tests which can include:
· Lumbar puncture in which the cerebrospinal fluid is tested for viral particles, especially herpes simplex virus. These tests can also exclude bacterial meningitis
· Brain scans (CT or MRI) - to exclude brain tumours, aneurysms and strokes and show the extent of any inflammation.
· An electroencephalogram (EEG) will help confirm a diagnosis of encephalitis by recording any unusual patterns of electrical activity in the brain.

It should be noted that it is not unusual for the results of some tests to be “normal”. It is important to initially exclude some more common and treatable diseases.

An antiviral medication, Acyclovir, will be prescribed. Acyclovir has significantly improved the outlook in cases of herpes simplex encephalitis but is not as effective against other viruses. Steroids may be prescribed for Post Infectious encephalitis. Other treatment for Encephalitis is symptomatic.

Provision of nutrition, fluids and rest will allow the body to fight the infection. Emotional support of agitated or confused persons is helpful.
After the acute phase of Encephalitis which may last from 1 to 2 weeks physiotherapy and speech therapy may be necessary and an assessment by a neuropsychologist is advised.

A proportion of people will be left with highly variable and often permanent consequences of the illness (acquired brain injury). These difficulties may include cognitive, physical, emotional or behavioural consequences. Specialist clinical support and rehabilitation are needed to help the person adjust to, and cope with, such difficulties.

Content and information courtesy of The Encephalitis Society