Encephalitis

Encephalitis comes from the Greek enkephalos meaning brain and it is meaning inflammation.
Encephalitis is irritation and swelling (inflammation) of the brain, most often due to infections.

Causes, Incidence and Risk factors

• Encephalitis is a rare condition. It occurs more often in the first year of life and decreases with age. The very young and the elderly are more likely to have a severe case.

Encephalitis is most often caused by a viral infection. Many types of viruses may cause it. Exposure to viruses can occur through:

• Breathing in respiratory droplets from an infected person

• Contaminated food or drink

• Mosquito, tick, and other insect bites

• Skin contact

• Encephalitis caused by the herpes simplex virus is the leading cause of more severe cases in all ages, including newborns.

A number of viruses for which there is now a vaccine may also cause encephalitis. These include:

• Measles

• Mumps

• Polio

• Rabies

• Rubella

• Varicella (chickenpox)

Other viruses that cause encephalitis include:

• Adenovirus

• Coxsackievirus

• Cytomegalovirus

• Eastern Equine Encephalitis Virus

• Echovirus

• West Nile virus

Other causes of encephalitis may include:

• An allergic reaction to vaccinations

• Autoimmune disease

• Bacteria, such as Lyme disease,syphilis, and tuberculosis

• Parasites such as roundworms, cysticercosis, and toxoplasmosis in AIDS patients and other people who have a weakened immune system

• The effects of cancer

Symptoms Some patients may have symptoms of a cold or stomach infection before encephalitis symptoms begin. When a case of encephalitis is not very severe, the symptoms may be similar to those of other illnesses, including:

• Fever that is not very high

• Mild headache

• Low energy and a poor appetite

Other symptoms include:

• Clumsiness, unsteady gait

• Confusion, disorientation

• Drowsiness

• Irritability or poor temper control

• Light sensitivity

• Stiff neck and back (occasionally)

• Vomiting

Symptoms in newborns and younger infants may not be as easy to recognize:

• Body stiffness

• Irritability and crying more often (these symptoms may get worse when the baby is picked up)

• Poor feeding

• Soft spot on the top of the head may bulge out more

• Vomiting

Emergency symptoms:

• Loss of consciousness, poor responsiveness, stupor, coma

• Muscle weakness or paralysis

• Seizures

• Severe headache

Sudden change in mental functions:

• "Flat" mood, lack of mood, or mood that is inappropriate for the situation

• Impaired judgment

• Inflexibility, extreme self-centeredness, inability to make a decision, or withdrawal from social interaction

• Less interest in daily activities

• Memory loss (amnesia), impaired short-term or long-term memory

Signs and tests

An examination may show:

• Abnormal reflexes

• Increased intracranial pressure

• Mental confusion

• Mouth ulcers

• Muscle weakness

• Neck stiffness

• Signs in other organs, such as the liver and lungs

• Skin rash

• Speech problems

Tests may include:

• Brain MRI

• CT scan of the head

• Culture of cerebrospinal fluid (CSF), blood, or urine (however, this test is rarely useful)

• Electroencephalogram (EEG)

• Lumbar puncture and CSF examination

• Tests that detect antibodies to a virus (serology tests)

• Test that detects tiny amounts of virus DNA (polymerase chain reaction --PCR)

Prognosis

• The outcome varies. Some cases are mild and short, and the person fully recovers. Other cases are severe, and permanent impairment or death is possible.

• The acute phase normally lasts for 1 -2 weeks. Fever and symptoms gradually or suddenly disappear. Some people may take several months to fully recover.

Treatment:The goals of treatment are to provide supportive care (rest, nutrition, fluids) to help the body fight the infection, and to relieve symptoms. Reorientation and emotional support for confused or delirious people may be helpful.

Medications may include:

• Antiviral medications, such as acyclovir (Zovirax) and foscarnet (Foscavir) --to treat herpes encephalitis or other severe viral infections (however, no specific antiviral drugs are available to fight encephalitis)

• Antibiotics --if the infection is caused by certain bacteria

• Anti-seizure medications (such as phenytoin) --to prevent seizures

• Steroids (such as dexamethasone) --to reduce brain swelling (in rare cases)

• Sedatives --to treat irritability or restlessness

• Acetaminophen --for fever and headache

• If brain function is severely affected, interventions like physical therapy and speech therapy may be needed after the illness is controlled.

Complications: Permanent brain damage may occur in severe cases of encephalitis. It can affect:

• Hearing

• Memory

• Muscle control

• Sensation

• Speech

• Vision

Prevention

• Children and adults should avoid contact with anyone who has encephalitis.

• Controlling mosquitoes (a mosquito bite can transmit some viruses) may reduce the chance of some infections that can lead to encephalitis.

• Remove any sources of standing water (such as old tires, cans, gutters, and wading pools).

• Wear long-sleeved shirts and pants when outside, particularly at dusk.

• Vaccinate animals to prevent encephalitis caused by the rabies virus.

RehabilitationAfter having viral encephalitis, you may need rehabilitation (rehab). This is a program to help you return to normal life as much as possible. Rehab helps you regain and relearn the skills of everyday living.

We may need any of the following:

1. Occupational therapy: Occupational therapy (OT) uses work, self-care, and play activities to help you in your daily life. OT teaches special skills for bathing, dressing, cooking, eating, or driving. An occupational therapist may help you choose tools to use, and suggest ways to keep your home or workplace safe. You and your therapist will plan a therapy program that is right for you.

2. Speech therapy: A speech therapist may work with you to help or improve how you talk.

3. Physical therapy: Your caregiver may want you to go to physical therapy. A physical therapist will help you with special exercises. These exercises help make your bones and muscles stronger.

In general, physical therapy begins with a specific diagnosis and a referral from a physician, often accompanied by recommendations for particular treatments. On the first visit, the physical therapist will conduct an evaluation assessing the individual's medical history, range of motion, strength, neurological involvement, and functional level.

Massage therapy is a manual method of treatment that helps restore movement and function of muscles and joints by improving circulation and eliminating metabolic toxins stored within muscles.

Acupressure is a manual technique in which pressure is applied to specific points on the body to relieve pain and promote balance among the physiological systems. Different acupressure points correspond to different areas of the body. For example, applying pressure to the area between the thumb and forefinger decreases headache.

Hydrotherapy utilizes whirlpools or Hubbard tanks to allow individuals to exercise in a warm, buoyant, gravity-eliminated environment.

Electrical stimulation passes electrical currents through surface electrodes to provide pain control or muscle re-education.

Heat treatment increases the extensibility of soft tissues, enhances blood flow, increases function of the tissue cells, and helps relieve pain. Ultrasound therapy converts electrical energy into mechanical sound waves that provide heat to deeper muscle, tendons, ligaments, and bone.