The varicella zoster virus causes both Ramsay Hunt syndrome and another common cause of facial weakness, Bell's palsy.

This virus is a relative of human herpes viruses (which cause fever sores on the mouth and genital herpes). The varicella zoster virus also causes two other diseases -- shingles (which is also a nerve infection, affecting the so-called "dorsal roots," the nerves of the sides of the trunk) and chicken pox (a disease characterized by an itchy rash, commonly affecting children).

The virus is believed to infect the facial nerve near the inner ear in this condition, which results in local inflammation (irritation and swelling with presence of extra immune cells). The extent of the symptoms may reflect the severity of the nerve inflammation.

Symptoms may include:

• facial weakness with difficulty closing one eye; the smile may look "crooked"
• Painful rash on the ear drum, tongue, or palate on the same side of the facial weakness
• hearing loss on one side
• Sensation of things spinning around (vertigo)

Diagnosis is generally determined by observation of evidence of facial weakness and a vesicular rash. Occasionally, a nerve conduction study will be done to determine the extent of damage to the facial nerve and potential for recovery.

The more severe the damage, the longer it will take to recover and the lower the chance of complete return to normal function. Occasionally, blood tests can be used to determine whether or not an infection with the varicella zoster virus has occurred.

There is a promising laboratory technique called "PCR", which can detect very small amounts of viral DNA in the affected skin. However, it is mostly used for research nowadays.

The use of neuroimaging (pictures of the brain), particularly MRI (magnetic resonance imaging), can sometimes show inflammation of the facial nerves and determine whether the infection has spread to other nerves or the brain. A spinal tap is used in rare cases, especially when the diagnosis is not clear.

Treatment with anti-viral medications, such as acyclovir or famciclovir is recommended for 7 to 10 days, along with strong anti-inflamatory drugs called steroids (such as prednisone) for 3 to 5 days.

The steroids are then tapered off in about one week. Sometimes strong pain killers are also needed if the pain persists despite the use of the steroids. During the period of facial weakness, an eye patch should be worn to prevent corneal abrasion and damage to the eye (if it does not close completely).

If damage to the nerve is minimal, then a full recovery is usually expected within a few weeks. If damage is more severe, there may not be full recovery -- even after several months.

Overall, chances of recovery are better if the treatment is started 3 days after the onset of the symptoms. Complete recovery is achieved by 70% of patients if treatment is begun at this time.

However, when the treatment is delayed more than 3 days, the chances of complete recovery drop to about 50%. Children are more likely to have a complete recovery than adults.

Recovery may be complicated if the nerve grows back to the wrong areas (synkinesis) which may cause inappropriate responses, such as tears when laughing or chewing (croc´s tears). Some other people may experience blinking of the eye when talking or chewing food.

Severe paralysis will result in incomplete or inappropriate recovery with potential for permanent facial paralysis and synkinesis.

Occasionally, the virus may spread to other nerves or even to the brain and spinal cord, causing headaches, back pain, confusion, lethargy, and limb weakness. This may prompt an admission to the hospital where a spinal tap may help to determine whether other areas of the nervous system have been infected.