Facial nerve disorders occur when nerves are damaged by illness or injury, causing the nerves to become paralyzed or hyperkinetic (that is, move involuntarily). Damage to nerves in the head and neck can produce mild to severe symptoms, and often cause emotional distress due to their impact on personal appearance.

Facial paralysis symptoms include:

	facial weakness or paralysis, preceded by numbness
	smooth forehead
	an inability to smile
	drooping corner of the mouth
	drooling
	tearing or decreased tearing
	inability to close an eye, which can lead to dehydration of the eye, ulcers on the cornea, infection, and possible loss of the eye
	impaired taste
	sound sensitivity in one ear
	earache
	difficulty speaking

Sometimes the symptoms of facial paralysis come on gradually, preceded by pain behind the ear, a ringing sound in the ears, or other symptoms. In all cases, accurate prognosis and effective management depend on early diagnosis.

Diagnosis
There are several disorders that affect the facial nerve. Among the main categories of conditions are hyperkinesis (spasms) and paralysis. Symptoms vary depending on the specific condition, but may include:

	Hyperkinesis (spasms), or spells of uncontrolled and sometimes painful blinking or other cranial or facial actions
	"Tics" or other involuntary movement brought on by stress or other environmental factors
	Sudden, involuntary movement that resists opposition; for example, the head tilting in one direction or eyes clamping tightly shut

There are several disorders associated with facial spasm that fall into four main categories:

	Blepharospasm-two-sided, involuntary closure of the eyelids
	Dystonia-blepharospasm with other involuntary facial, oral, or jaw movement
	Hemifacial spasm-spasms affecting one full side or both sides of the face
	Aberrant regeneration-involving the eyes, lip-cheek area, chin or whole face and usually following trauma or surgery

Accurate diagnosis of the precise condition can only be done by a facial nerve specialist.

Testing may include:

Hearing test
This will determine if nerve damage involves the hearing nerve, inner ear, or hearing mechanism.

Balance test
This will test to see if balance nerves are involved.
Tear test
A tear test measures the eye's ability to produce tears.
Computed tomography (CT) scan or magnetic resonance imaging (MRI) scan

These tests check for an infection, tumor, bone fracture, or other problem in the area of the facial nerve.

Electrical test
This test will see if the facial nerve is damaged.
Blood tests
These tests check for diabetes, HIV infection, or Lyme disease.

Treatment options include:
Physical therapy and self-management

Medications to reduce pain or control spasms, or antibiotics and antiviral agents to treat underlying infections

Injections of botulinum-a toxin to paralyze the nerve and control spasms

Surgery-including nerve grafts (for certain cases of facial paralysis), microvascular decompression or selective myectomy (for certain cases of facial spasm), and surgery to relieve pressure on the nerve or cut the nerve (for certain cases of neuralgia)