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  • Facial palsy

  • Peripheral facial paralysis

ICD-9-CM Code

ICD-10-CM Code

  • G51.0 Bell's palsy, facial palsy

Preffered Practice Practice Pattern

  • 5F: Impaired peripheral nerve integrity and muscle performance associated with peripheral nerve injury1

Key Features


  • Paralysis or weakness of the muscles on one side of the face.

  • Sudden onset, often overnight.

  • Damage to the seventh cranial (facial) nerve that controls muscles on one side of the face causes that side of face to droop.

  • Nerve damage to the nerve may affect sense of taste and production of tears and saliva.

Essentials of Diagnosis

  • Lower motor neuron disease (LMN).

  • Diagnosis is usually made by history and clinical examination.

General Considerations

  • Afflicts approximately 40,000 Americans each year


  • Men and women equally

  • Any age, but it is less common before age 15 or after age 60

  • More prevalent in people who have diabetes or upper respiratory ailments such as the flu or a cold

  • More in pregnant women

Clinical Findings

Signs and Symptoms

  • Sudden weakness or paralysis on one side of the face that causes it to droop: main symptom

  • Difficulty in closing the eye on the affected side

  • Drooling

  • Dry mouth

  • Eye problems, such as excessive tearing or a dry eye

  • Loss of ability to taste

  • Pain in or behind ear

  • Numbness in the affected side of your face

  • Increased sensitivity to sound

  • Headache

  • Facial twitch

  • Inability to smile or make facial expressions

Functional Implications

  • Dry eyes

  • Eating

  • Hearing

  • Psychological impact

Possible Contributing Causes

  • In most cases of Bell palsy, the nerve that controls muscles on one side of the face is damaged by inflammation.

  • The cause of Bell palsy is not clear.

  • Most cases are thought to be caused by the herpes virus that causes chickenpox and shingles, and Epstein-Barr virus that causes mononucleosis.

Differential Diagnosis

  • Stroke

  • HIV infection

  • Herpes simplex virus

  • Infections

  • Lyme disease

  • Middle ear infection

  • Meningitis

  • Diabetes mellitus

  • Sarcoidosis

  • Brucellosis

  • Tumors

  • Ramsay Hunt syndrome

Means of Confirmation or Diagnosis


  • Magnetic resonance imaging (MRI) of the head looking for a brain tumor

  • Computed tomography (CT) scan of the head looking for a brain tumor

Diagnostic Procedures

  • History and physical and neurologic examination to check facial nerve function

  • If cause of symptoms is not clear, following tests are needed:

    • - Nerve conduction test for facial nerve

    • - Electromyography (EMG) for facial nerve

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