Facial nerve paralysis
Facial nerve paralysis is a medical condition involving the complete loss of voluntary movement in the facial muscles on one or both sides of the face due to damage or dysfunction of the facial nerve (cranial nerve VII). This condition can affect a person's ability to perform basic functions like blinking, smiling, and speaking, and it can significantly impact facial expressions and symmetry.
Causes of Facial Nerve Paralysis
Bell's Palsy: The most common cause of facial nerve paralysis, characterized by sudden, unexplained onset. It is thought to be related to viral infections that cause inflammation of the facial nerve.
Trauma: Fractures of the facial bones or trauma directly to the facial nerve can lead to paralysis.
Infections: Lyme disease, herpes zoster oticus (Ramsay Hunt syndrome), and other viral or bacterial infections can lead to inflammation and damage to the facial nerve.
Neoplasms: Tumors such as acoustic neuromas or parotid gland tumors may compress or invade the facial nerve.
Neurological Disorders: Conditions like stroke or multiple sclerosis can affect the brain areas responsible for facial control, leading to paralysis.
Surgical Complications: Facial nerve damage is a potential risk in surgeries of the head and neck area, including ear and brain surgeries.
Symptoms
Inability to control facial muscles on the affected side
Drooping of the eyelid and corner of the mouth
Loss of facial expression
Dry eye or excessive tearing
Drooling
Loss of taste sensation on the front two-thirds of the tongue
Hypersensitivity to sound on the affected side (hyperacusis)
Diagnosis Diagnosis primarily involves a physical examination to assess the extent of muscle weakness and rule out other possible causes of the symptoms. Additional diagnostic tests might include:
Electromyography (EMG): Measures the electrical activity of muscles.
Imaging Tests: MRI or CT scans can help identify the cause, such as a tumor or inflammation.
Blood Tests: Used to check for infections like Lyme disease or conditions like diabetes.
Treatment Treatment of facial nerve paralysis depends on the underlying cause:
Corticosteroids: Often used in cases of Bell's palsy to reduce inflammation.
Antiviral Medications: Used if a viral infection is suspected.
Physical Therapy: Helps maintain muscle tone and stimulate facial muscles.
Surgery: May be necessary in cases of tumors or severe trauma.
Eye Care: Protecting the eye from dryness due to inability to blink is crucial. This may involve using eye drops, ointments, or taping the eye shut during sleep.
Prognosis The prognosis for facial nerve paralysis varies based on the cause and severity of the nerve damage. Many patients with Bell's palsy, for example, recover fully with minimal treatment, though recovery might take several weeks to months. In cases caused by more severe conditions like tumors or stroke, the recovery might be partial or require surgical intervention.
Facial nerve paralysis is a complex condition with potentially significant impacts on daily life and emotional well-being, and managing it effectively requires a multidisciplinary approach tailored to the specific needs and underlying cause in each case.
Facial nerve paralysis is a common problem that involves the paralysis of any structures innervated by the facial nerve. The pathway of the facial nerve is long and relatively convoluted, and so there are a number of causes that may result in facial nerve paralysis.
The most common is Bell's palsy, an idiopathic disease that may only be diagnosed by exclusion.
see Delayed facial palsy after vestibular schwannoma surgery.
Surgical treatment of posterior cranial fossa and cerebellopontine angle tumors is associated with a risk of facial nerve dysfunction. The causes for facial muscle paresis include nerve compression by the tumor, destruction of the nerve structure by the tumor growing from nerve fibers, nerve injury during surgical removal of the tumor, etc. The first 3 months after facial nerve injury are a potential therapeutic window for the use of botulinum toxin type A (BTA). During this period, the drug is introduced both in the healthy side to improve the facial symmetry at rest and during mimetic movements and in the affected side to induce drug-induced ptosis. Post-paralytic syndrome develops 4-6 months after facial nerve injury. At this stage, administration of BTA is also an effective procedure; in this case, drug injections are performed on the affected side at small doses and symmetrically on the healthy side at doses doubling those for the affected side. BTA injections are mandatory in complex treatment of facial muscle paralysis 1).