Facial Nerve Paralysis
The facial nerve (7th cranial nerve) is a nerve that plays an important role in communication and expression. It controls the muscle function in the face and is responsible for :
- Facial expression - The motor supply to the muscles of face that includes frontalis, orbicularis oculi, buccinators, and orbicularis oris and stapedius.
- Tear film in the eye and salivary glands - Parasympathetic nerves supply to the lacrimal (eye) and submandibular glands (salivary glands)
- Sensation in the tongue - Sensory input from the anterior two thirds of the tongue
Dysfunction of facial nerve severely affects the quality of life. Loss of facial movement due to nerve damage is referred to as facial nerve paralysis (FNP). It involves the paralysis of the structures associated with the facial nerve.
Causes Of FNP
Facial paralysis can happen on one or both sides of the face. There are number of causes that lead to FNP. Common causes include:
- Bell's Palsy: It is the most common cause of facial paralysis. It is the paralysis of facial nerve with an unknown cause. It is sometimes associated with viral infections.
- Infection or inflammation of the facial nerve: Infections of the ear or face, or herpes zoster of the facial nerve (Ramsay Hunt syndrome)
- Head trauma: such as birth trauma, skull base fractures, facial injuries, middle ear injuries, or surgical trauma
- Head or neck tumour: including acoustic neuroma, schwannoma, cholesteatoma, parotid tumors, and glomus tumors
- Stroke: caused by a lacunar infarct affecting fibers in the internal capsule going to the nucleus. The facial nucleus itself can be affected by infarcts of the pontine arteries.
- Other causes include diabetes mellitus, autoimmune disorders like Sarcoidosis and Amyloidosis.
Facial paralysis can appear suddenly or gradually over a period of months. Based on the cause, the paralysis might last for a short or extended period of time.
Symptoms Of FNP
- Unilateral facial weakness
- Weakness in the arms or legs
- Loss of taste (hyperacusis)
- Decreased salivation and tear secretion.
- Vesicles in the ear (occur if the facial palsy is due to shingles)
- Acute facial pain radiating from the ear may precede the onset of other symptoms.
- Inability to blink or close the eye is a common symptom.
The effect of facial palsy on the facial muscles and facial function include:
Forehead: Loss of forehead wrinkles and inability to frown
- Droopy eyebrow and inability to raise eyebrow
- Inability to close the eye fully or blink
- Watery eye or dry eye
- Inability to squint
- Drooping of the lower eyelid which may make the eye appear wide
- Painful eye with symptoms of grittiness or irritation
- Sensitivity to light
- Soreness or redness of the white of the eye
- The corner of the mouth pull droops
- Inability to smile on the affected side
- Inability to puff up your cheeks, whistle or blow
- Altered taste
- Tingling of the affected half of the tongue
- Difficulty eating, drinking, brushing your teeth and spitting out
- Excess or reduced salivation (dry mouth)
- Inability to pout
- Difficulty speaking because of weakness in the lips and cheek
- Pain in or near the affected ear
- Loss of hearing
- Increased sensitivity to high pitched noise
- Nose runs or feels stuffy
- Inability to flare nostril
- Inability to wrinkle nose
Diagnosis Of FNP
First steps in making a diagnosis include a thorough medical history and physical examination, including a neurological examination. If an individual develops any of the above symptoms of facial palsy slowly, they should immediately consult physician for further investigation.
Causes for facial nerve disorder vary from unknown to life threatening. The treatment depends upon the cause of the FNP. Therefore, it is important to investigate the cause of the problem. The tests used for the diagnosis varies from patient to patient.
Diagnostic tests to investigate the cause of FNP include:
- Hearing tests: Hearing tests are performed to assess the status of the auditory nerve. The stapedial reflex test can evaluate the branch of the facial nerve that supplies motor fibers to one of the muscles in the middle ear.
- Balance tests: Will help in finding out which part of the auditory nerve is involved.
- Tear, Salivation and Taste tests: Helps to locate the site and severity of a facial nerve lesion.
- Schimer's tear test: helps in investigation of reduced flow of tears on the side of palsy
- Imaging studies: Imaging studies help to determine if there is infection, a tumour, a bone fracture, or any other abnormality. These studies usually include a CT scan and/or a MRI scan.
- Electrical nerve stimulation tests: Stimulation of the nerve by electrical current helps in investigating whether the nerve can still cause muscles to contract. It helps in the evaluation of progression of the disease.
The House-Brackmann Facial Nerve Grading System is widely used to characterize the degree of facial paralysis
- Grade I - Normal facial function in all areas
- Grade II - Slight Dysfunction
- Grade III - Moderate Dysfunction
- Grade IV - Moderate Severe Dysfunction
- Grade V - Severe Dysfunction
- Grade VI - Total Paralysis
Facial Nerve Paralysis: Classification
Facial nerve Palsy can be classified into two types on the basis of the nucleus level. Nucleus (group of cell bodies of facial nerve) is the principal part of facial nerve and it lies in the pons (in the brain stem).
- Supranuclear palsy: The lesion lies above the nucleus of facial nerve in pons. It causes weakness of lower part of the face. Paralysis of the face muscles occur opposite to the side of lesion.
- Infranuclear palsy: The lesion lies below the nucleus of facial nerve.
Management of FNP
Treatment varies depending upon the cause of the FNP:
- General measures: FNP is characterized with eye problems. Lubricating drops can be used to prevent irreversible blindness. Botulinum toxin may also give temporary relief. Antiviral and steroids helps in the speedy recovery.
- Physiotherapy: Helps in maintaining the muscle tone of the affected facial muscles and stimulation of the facial nerve. Physiotherapy also helps to prevent permanent contractures of the paralyzed facial muscles.
- Surgery: For the patients not responding to above treatments, surgical decompression can be done. There is a risk of hearing loss associated with this surgery. Possible surgeries include:
- Cosmetic surgery to elevate mouth.
- Nerve repair or nerve grafts regenerates facial nerve at a rate of 1mm/day. In this procedure we do direct microscopic repair of damaged or cut nerve.
- Nerve transposition: The hypoglossal nerve (12th cranial nerve) is connected to the existing facial nerve. The patients can then train themselves to move their face by moving their tongue.
- Sling procedure: In muscle transposition the temporalis muscle is moved down and connected to the corner of the mouth to allow movement of face.
- Other procedures: In reconstructive surgery following facial nerve palsy, a brow lift or facelift, partial lip resection, eyelid repositioning, lower eyelid shortening, upper eyelid weights, or eyelid springs can also be performed.
Why Choose BSR for FNP?
BSR ENT Hospital is one of the renowned ENT Specialist Hospitals in Hyderabad and Secunderabad with a high success rate of surgeries and clinical outcomes, since the past 40 years. Trained and Experienced ENT specialists are skilled at delivering the best in treatment solutions for all ENT disorders. BSR applies a comprehensive approach to treatment of FNP integrating advanced therapies spanning from rehabilitation to medical management to surgical repair.
The team includes trained and experienced ENT specialists, radiologists, surgeons and advanced practice providers who utilize the latest technologies to diagnose and manage FNP. They strive to provide the best treatment solutions with utmost care and compassion at affordable price.
The doctors spend time with the patient to provide complete information on the condition and the proposed treatment plan before beginning the treatment.
The hospital is equipped with emergency care facility enabling patients to recieve immediate consultations and avoid discomfort.