Bell’s palsy is a rare facial paralysis that affects pregnant mothers or women shortly after giving birth.
Bell’s palsy can develop late in the third trimester or just after giving birth.
What Bell’s palsy means
Bell’s palsy is an episode of facial muscle weakness or paralysis that begins suddenly and worsens over 48 hours, causing pain and discomfort. It is named after Sir Charles Bell, a 19th Century surgeon from Scotland who identified the connection between the condition and facial nerve damage.
What causes Bell’s palsy
The condition occurs due to inflammation of the facial nerve, or the seventh cranial nerve (CN VII), resulting in paralysis. No conclusive cause has been determined yet, but it has been associated with viruses such as influenza, herpes, common cold, and throat infections; diabetes; low immunity; chronic high blood pressure; obesity; and chronic stress.
Who can have Bell’s palsy
Bell’s palsy affects men and women equally, but it is less common before age 15 or after age 60. Among women of child-bearing age, studies have shown that the condition is more common in expectant mothers — often occurs in the third trimester or within seven days of giving birth.
The causes of Bell’s Palsy in expectant mothers
The exact cause of Bell’s palsy is not yet known. Experts think that it may be due to inflammation of the facial nerve, the nerve that controls the movement of the muscles in the face. But what triggers the inflammation is not clear.
However, the condition has been associated with the following situations:
The activation of herpes simplex viruses in the temporal bone behind the ear: The physiological stress in pregnancy can cause the activation of latent herpes simplex viruses. Those viruses can cause inflammation of the facial nerve, which leads to facial weakness or paralysis.
Upper respiratory tract infections: Bell’s palsy is more likely to happen to those who have respiratory infections like the common cold or influenza.
Preeclampsia: The condition is often used to predict preeclampsia during pregnancy with fivefold greater rate of gestational hypertension and preeclampsia.
HELLP syndrome (hemolysis, elevated liver enzymes, and low platelet count): The condition has been linked with Bell’s palsy.
Other predisposing factors include:
- High blood pressure
- Lyme disease
- Guillain-Barré syndrome
- Myasthenia gravis
- Multiple sclerosis
Signs and symptoms of Bell’s palsy
Some of the most common symptoms and signs of Bell’s palsy include:
- Trouble smiling, pouting, or squinting,
- Eyelids and mouth corners drooping
- Weakness or twitching on the affected side of the face
- Eyes and mouth experiencing dryness
- Difficulty speaking
- Loss of sense of taste
- Discomfort or aching in the jaw region or near the ears
- A loud ringing sound in either or both ears
- Oversensitivity to most loud sounds
- Headaches and dizziness
- Unable to lift the eyebrow, blink, or close the eye on the affected side
- Overproduction of tears as a response to the dryness
How Bell’s palsy is diagnosed
Your doctor may start by examining your symptoms and signs. They will check your hearing to ensure you can hear everything clearly, including checking for ringing sounds or tinnitus. They will also check your vestibular functions to understand balance and dizziness symptoms.
The level of tear fluid production may also be checked, while your nose and throat are examined to check for signs of infections and problems with eating and drinking. The doctor will also check for rashes around the ears or scalp.
There are no specific tests used to diagnose Bell’s palsy. However, to rule out other conditions that can cause similar symptoms and to determine the extent of nerve involvement, your healthcare provider may order the following tests:
- Blood tests to check whether another condition, such as diabetes or Lyme disease, is present
- Electromyography (EMG) to determine the extent of the nerve involvement
- Magnetic resonance imaging (MRI) or computed tomography (CT) of the brain and auditory canals to determine if there is a structural cause for your symptoms
How Bell’s palsy is treated in pregnant women and nursing mothers
Most cases of Bell’s palsy are mild enough to not need any treatment, as the condition resolves by itself within two weeks to a month. In some cases, the only treatment required is protecting the eye from drying at night or while working at a computer. The patient may be given an eye drop to use during the day or an ointment at bedtime. This helps protect the cornea from being scratched, which is crucial to the management of Bell’s palsy.
Other supportive treatment includes analgesics to relieve pain and physical therapy to stimulate the facial nerve and prevent the paralyzed muscles from shrinking and tightening. In rare severe situations, facial nerve decompressions may be done prior to delivery. Relaxation, multivitamins, acupuncture, electrical stimulation, and biofeedback training might also help.
Other treatment options, such as short courses of prednisolone and antiviral medications could be considered but usually avoided according to safety concern in pregnancy.
When to call your doctor
Once diagnosed with Bell’s palsy, the condition usually starts to improve within 2 weeks. However, it may linger for up to 3-6 months before normalcy returns. Be sure to inform your doctor if there is no improvement or the symptoms get worse.
Dr. Wanwadee Sapmee Panyakat (OB-GYN) (1 June 2022)