Bell’s palsy or Idiopathic facial paralysis
It is defined as a paralysis(loss of nerve function or muscle power resulting in an inability to move) or weakness of the muscles of one side of face. Damage to facial nerve that controls the muscles on one side of face causes that side of face to droop means that side become flat, expressionless, taste , tear, saliva may be affected. Several diseases can cause facial paralysis, but if no specific cause can be identified it is bell’s palsy. It is the most common mono neuropathy(disease involving only one nerve).
It is idiopathic(arising spontaneously or disease of own kind), unilateral(affecting one side of face) facial nerve paralysis. The hallmark of this condition is rapid onset of partial or complete paralysis oftenly occurs over night. very rarely occur bilaterally (affecting both sides) result in total facial paralysis or weakness. It is thought that an inflammatory condition leads to swelling of facial nerve. The nerve travel through the skull behind the ear. Nerve swelling and compression lead to nerve damage.
Causes of Bell’s palsy
Viral and bacterial infections as well as autoimmune disorders appear to be emerging as the most frequent common threat in the cause of Bell’s palsy
1) herpes simplex virus(HSV-1)
HSV-1 was suggested as cause of Bell’s palsy. Exposure to HSV-1 is common. Most people are exposed during childhood. Kissing between relatives is the most frequent common source of exposure but may also be spread while sharing towels, utensils etc. the virus then enters the dormant state residing on the nerve tissue. Several triggers activate the virus. When the virus get activated, inflammation occurs. If inflammation occurs in an area where no room for swelling is to expand the nerve itself become inflamed or inflammation within the canal exerts pressure on the nerve results in compression that prevents the transmission of signals to the muscles. When muscles are not able to receive signals to contract and relax, muscles become weakened and then paralysed. The triggers that are responsible for the activation of virus before the onset of Bell’s palsy are impaired immunity, stress, lack of sleep, minor illness, physical trauma, upper respiratory infections, auto immune diseases etc.
Other viruses include cytomegalo virus, Epstein-barr virus, rubella and mumps virus are also responsible.
HIV can cause facial paralysis and increase the chance of developing Bell’s palsy.
3) Bacterial trigger
Bacteria from some acute middle ear infection can enter the canal and as with virus bacteria can evoke an inflammatory response and compress the nerve.
4) Other causes
Facial and surgical wounds, trauma due to blunt force, temporal bone fracture, brain-stem injury, cyst and tumours can result in Bell’s palsy. Diabetes and thyroid condition are also associated with Bell’s palsy.
Signs and symptoms of Bell’s palsy
Bell’s palsy is characterized by facial drooping(mouth appears to be flat and expressionless)on the affected half, due to the improper functioning of the facial nerve(7th cranial nerve) which controls the muscles of face. Forehead muscles receive innervation from both sides of brain therefore forehead can still be wrinkled by a patient whose facial palsy is caused by a problem in one hemisphere of brain. inability to close the eye. Smile wrinkle the forehead and whistle. Speech may be mildly slurred.
1) muscle weakness or paralysis
2) forehead wrinkle disappear
3) overall droopy appearance
4) impossible or difficult to blink
5) nose run
6) difficulty in speaking
7) difficulty in eating and drinking
8) sound appears to be loud on affected side(hyperacusis)due to the paralysis of stapedius muscle
9) excess or reduced salivation
10) diminished or distorted taste
11) pain in or near the ear
1) eye closure difficult/impossible
2) lack of tears
3) excessive tearing
4) brow drop
5) sensitivity to light
1) eye appear smaller
2) blink remain incomplete
3) mouth pulls up and outwards
Treatment of Bell’s palsy
The first priority in treating Bell’s palsy is to eliminate the source of damage to the nerve. Therefore medication like(prednisone and anti virals) may help to relieve the compression.
Rest is important. Enough rest to maintain strength and immunity. Food particles can lodge between gums and cheek therefore oral hygiene should be maintained.
c) for pain
for pain or discomfort moist heat can help. During the earliest days of Bell’s palsy, when the muscles are completely flaccid, moist heat(ease soreness and reduce swelling), massage(provide degree of motion) and stimulation to the muscles(increase circulation) should be given.
Take extra care to keep your eye moist. Incase if eyes become dry put eye drops in them. Manually blink your eyes using back of your fingers at regular intervals. If there is history of middle or inner ear problem an ear plug may be used. In the presence of Bell’s phenomenon(eye ball turns upward as we attempt to close the eye).
Then concentrate on looking downward towards the floor.
d) facial exercises
1) to relax the cheek(if the side of mouth is pulling up and to the side or cheek feels tight)
in this put your thumb inside your cheek at an angle toward the centre of ear. Grasp the outside of cheek with fingers and pull down and forward. Hold it for minimum 10 seconds upto 30 seconds is good. Shift the position towards the centre and repeat the stretch and hold. Shift still further towards the centre and repeat.
Practice speaking in front of a mirror, repeating words that use M,B,F and P while keeping yours eyelid open., in the beginning, speak softly and slowly.
Stretch muscles of the neck by tilting your head to the side and slightly back, hold it for 10 seconds.
Massage your face(both sides)using from circular motion. Start in centre and work your way out.
2) Other exercises
a) Compress lips together , pucker lips and attempt to whistle.
b) Smile without showing teeth , then smile showing teeth
c) Harden(wrinkle) the chin
d) Try to chew food using both sides of the mouth