Bell’s Palsy: The Mona Lisa Syndrome
19 Jun 2003
"How could it happen so quickly?" a patient asked me. A day earlier she could smile, open her eyes and showed normal facial countenance. Now, her face drooped on one side due to a paralysis of the facial nerve. The cause? A condition known as Bell’s Palsy.
Sir Charles Bell, a 19th century Scottish physician, first described this upsetting malady that distorts the face, often freezing the mouth making it difficult to eat and the speech slurred.
Bells’ Palsy has often been associated with one of the most famous paintings in the history of art, the Mona Lisa. In 2003 she occupies occupies her own room at the Louve in Paris. And it’s her slanted smile that attracts the viewer’s attention. The facial contraction that develops after Bell’s palsy is akin to the smile of Mona Lisa.
Bell’s palsy affects 45,000 North Americans every year. Teenagers and those in their 20’s are the most vulnerable after which the incidence levels off until age 60 when it begins to climb again.
Pregnant women are also more prone to this disease. About eight per cent of those affected have a family history of this disease. And diabetics are five times more likely to suffer this affliction.
Bell’s palsy results from an acute inflammation of the facial nerve. The anatomy of the skull sets the stage for possible trouble. To reach the facial muscles the nerve must pass through a tiny, tortuous, bony passageway in the thick part of the skull just behind the ear.
It’s a tight squeeze for the nerve under normal conditions. But when it becomes inflamed in this narrow passageway it’s the start of a vicious cycle. Increased pressure from the swelling further constricts the nerve and interrupts the blood supply causing death of nerve cells. The Mona Lisa smile results.
What triggers inflammation of the nerve has always been a mystery. Now, researchers believe that in most cases it’s the result of infection of the facial nerve by the herpes simplex virus. It’s the same virus that causes cold sores.
The herpes simplex virus is sneaky with the ability to remain in hibernation for years. What wakens it is an unsolved question. The main theory is that our immune system weakens due to stress or other factors allowing the virus to strike.
Diagnosis normally does not require extensive tests. The fact that the face suddenly droops within a day or two is the hallmark of this condition. However, if paralysis is slow and gradual then a tumour should be suspected.
Fortunately, the nerves outside of the brain and spinal cord have a great capacity to heal. Consequently, the majority of patients with Bell’s Palsy recover without the use of medication.
But doctors believe there’s less risk of developing the Mona Lisa smile if treated with prednisone, an anti-inflammatory drug, along with an anti-viral such as Valtrex. This increases the chance of recovery by about 20 per cent.
But it’s vitally important to start this medication within the first two or three days after the symptoms appear. If treatment is delayed it’s like closing the barn door after the horse has escaped. By this time the nerve cells have already been damaged. Moreover, anti-viral drugs must be used early to stop the reproduction of the virus.
This summer and fall there is one way to prevent Bell’s Palsy. Wear long-sleeved shirts and long pants tucked into socks while walking in wooded areas. This will prevent being bitten by an tick infected with Lyme Disease. And do a tick inspection at the end of the walk to promptly remove any ticks.
There’s about one chance in 100 that a tick bite will cause Lyme Disease. And if it happens about 15 per cent of patients will develop neurological symptoms, and the most common being Bell’s Palsy.
Since Bell’s Palsy affects the muscles of the eyelids as well they are often unable to blink. This will cause severe damage to the sensitive cornea unless eye drops are used during the day and a eye gel during sleeping hours.
