What is Bell’s palsy?
Bell’s palsy is a disorder of the facial nerve that causes muscle paralysis and drooping of one side of the face. This condition was named after a Scottish neurologist Sir Charles Bell who first identified it in 1821. In this condition, the facial nerve (7th cranial nerve) becomes irritated and inflamed which causes loss of voluntary control of the muscles it innervates. The facial nerve provides nerve supply to the muscles which control movements such as raising eyebrows, closing eyelids, nose wrinkling, smiling and opening and closing of the mouth. Due to the functional loss of the facial nerve, the person cannot perform these movements voluntarily.
This condition usually appears as sudden weakness or paralysis of one side of the face and the person feels their face is drooping on one side. Symptoms also include the inability to close one eyelid, altered sensation on the affected side, mouth drooling and drying of the eye on the affected side.
What are the Causes?
In this condition, inflammation of the facial nerve occurs which causes it to swell at the point where it leaves the skull. This causes ischemia (loss of blood supply) of the nerve making it unable to supply impulses to the facial muscles. The specific cause behind this dysfunction of the facial nerve is not known until now that’s why Bell’s palsy is also called Idiopathic facial palsy. It is diagnosed through exclusion i.e. when all other causes of facial nerve paralysis are eliminated then the person is said to have Bell’s palsy. Although in most cases, the cause is not clear but research suggests that the majority of cases might be linked to Herpes Simplex infection.
How is it treated?
- Corticosteroids and anti-viral medications
- Eye protection such as eye patch and eye drops
- Physiotherapy (exercise, facial massage, acupuncture and electrical stimulation)
The first line of treatment for Bell’s palsy is providing the patient with corticosteroids and anti-viral medications which have proven to be effective in the initial stage of 72-hours from the onset of symptoms. Most people also recover without any treatment within a few weeks and a few months. However, if diagnosed early, the doctor will prescribe corticosteroids and anti-viral medications if the patient can take them within 2 to 3 days of onset.
How can Physiotherapy Help?
The physiotherapist will evaluate your medical history and check your current symptoms at your first consultation. They might also conduct a physical examination to check the weakness in your facial muscles. The physiotherapist will then:
- Explain to you about your current symptoms and how they can be managed effectively.
- Educate you to prevent dryness in your eye by covering with an eye patch or using eye-drops.
- Teach you how to carefully close your eyelid with your fingers.
- Teach you facial exercises that will strengthen the muscles of the weak side of your face.
- Electrical stimulation such as TENS (Transcutaneous Electrical Nerve Stimulation) is also used sometimes for stimulating the facial muscles and maintaining the muscle tone. Physiotherapy is overall directed towards restoring the strength of facial muscles and maintaining their tone and symmetry.