Causes and Diagnoses

Causes and Diagnoses of Bell Palsy

Bell palsy occurs when the facial nerve is inflamed, swollen or compressed. The cause of the inflammation is not exactly known. Most researchers believe the swelling and inflammation comes from a viral infection, such as herpes simplex (the cold sore virus) or viral meningitis. As the nerve swells, it becomes compressed and restricts the flow of blood to the nerve cells.

Bell palsy is found in people with a variety of disorders, but more research must be conducted to understand its frequent connection to conditions such as:

Diagnosing Bell palsy

There is no specific test to identify Bell palsy, but diagnosis will begin with tests to ensure that symptoms are not related to a stroke or tumor. Once those two conditions are eliminated, the symptoms may clearly point to Bell palsy.

Additional testing may be conducted to determine the extent of the damage to the facial nerve. Tests may include:

  • Blood tests: Lab tests can identify if other conditions, such as diabetes or Lyme disease, are involved
  • Electromyogram (EMG): This test can confirm nerve involvement and measure the severity of the damage.
  • Computed tomography (CT) or magnetic resonance imaging (MRI): These tests help determine if there is a structural cause for your symptoms.

Diagnostic Tests