This transcript has been edited for clarity.
Donald, a 40-year-old man, consults you in surgery, having woken up in the morning with weakness affecting the right-hand side of his face. He's not experiencing any change in his vision or speech, but he is more sensitive to loud noises and describes some ear and postauricular pain. There's no history of limb weakness.
There's no past medical history of note, and he's not taking any prescribed medication, any medication over the counter, and he denies any illicit drug use. On examination, you notice a complete right facial palsy with no forehead sparing. He is able to close his right eye. There are no other neurologic signs of note, and examination of his ears is unremarkable.
Donald likely has a diagnosis of Bell's palsy. What do we need to know about Bell's palsy and primary care? Bell's palsy is characterized by an acute-onset, unilateral lower motor neuron facial palsy, with onset usually within 72 hours. Annual incidence is about 1 in 5000 with a lifetime risk of 1 in 60, and an average GP will see around one case every 2 years.
Reassuringly, people with Bell's palsy begin to recover even without treatment within 2-3 weeks, and complete recovery usually occurs within 3-4 months. With respect to facial function, the likelihood of significant improvement is related to the initial severity of facial weakness.
Over 90% of people with an incomplete paralysis and around 70% of people with a complete paralysis recover completely within 6 months, even without intervention. These are quite reassuring numbers, aren't they?
Importantly, Bell's palsy is a diagnosis of exclusion. There are certain other diagnoses we need to exclude before establishing a diagnosis of Bell's palsy.
We need to exclude neurologic conditions such as stroke disease. Stroke disease, of course, is an upper motor neuron palsy, so we should ask individuals to wrinkle their forehead. In upper motor neuron palsy, there is forehead sparing because there's no involvement of the occipitofrontalis muscle, as it's bilaterally innervated.
Other neurologic conditions to exclude are Guillain-Barré syndrome and multiple sclerosis. We also need to exclude malignancy, cerebellopontine angle tumors, cerebral tumors, and parotid tumors.
We also need to exclude infections such as otitis media, mumps, rubella, and Ramsay Hunt syndrome, which is a complication of varicella zoster virus infection affecting the facial nerve, resulting in facial palsy, ear and facial pain, and also a vesicular ear rash. We should also exclude Lyme disease or Borrelia burgdorferi infection from a tick bite, where symptoms can actually be bilateral.
The facial nerve innervates the lacrimal glands, the salivary glands, the stapedius muscle, taste fibers from the anterior tongue, and general sensory fibers from the posterior ear canal and tympanic membrane.
Therefore, in Bell's palsy, in addition to unilateral facial weakness, signs and symptoms can include ear and postauricular pain, dryness of the eye and mouth, taste disturbance in the anterior two thirds of the tongue, and hyperacusis, or sensitivity to loud noises. There can also be reduced sensation in the C2 dermatome, affecting the neck and occiput.
Incomplete eye closure, or lagophthalmos, is a particular concern and can lead to corneal abrasions, ulceration, and scarring. I'll come back to this shortly.
How do we manage Bell's palsy in primary care? Steroids remain the mainstay of treatment and should be started within 72 hours of the onset of symptoms.
There's no universal consensus on the optimum dosing regimen, but options include prednisolone 25 mg twice a day for 10 days or prednisolone 60 mg daily for 5 days, followed by a daily reduction in doses of 10 mg for a total of 10 days.
If we do treat with prednisolone within 72 hours of symptom onset, over 80% of people fully recover facial motor function after 6 months or more, with most showing improvement from 3 weeks onwards. This is compared with 70% or so of people who do not receive treatment within 72 hours.
What about antiviral therapy? Over the years, this has been recommended in some guidance. Actually, there's no current evidence to suggest that oral antiviral therapy alone is effective for Bell's palsy, except in the context of Ramsay Hunt syndrome. There is some emerging evidence that antiviral therapy in combination with steroids may be helpful, but this should be administered under specialist advice.
A key piece of management of Bell's palsy in primary care is to assess eye closure and eye protection measures. We should prescribe liberal amounts of artificial tears during the day and a thicker ointment-based lubricant with taping of the affected eye at night to prevent corneal abrasions and even permanent visual loss.
In fact, we should consider referring all those with incomplete eye closure to our ophthalmology colleagues. Facial Palsy UK is a useful UK-based website that provides patient information on the importance of eye care, dry eye advice, and taping eyes shut at night in the context of facial palsy.
Finally, we should consider referring all those with Bell's palsy who show no improvement in facial movements after 3 weeks' onset, typically to our ENT colleagues.
For Donald, then, we need to exclude other causes of facial weakness. To establish a diagnosis of Bell's palsy, I need to exclude stroke, infection, and malignancy. If a diagnosis of Bell's palsy is established, we should start steroids. I usually prescribe prednisolone 25 mg twice a day for 10 days.
We need to assess his eye closure. Indeed, he can close his right eye, but I still need to reinforce the importance of good eye care and prescribe liberal amounts of eye lubricant for both day and night. If he is unable to close his eye, I should consider referring him to my ophthalmology colleagues.
If his symptoms haven't resolved within 3 weeks, particularly his facial movements, I should also consider referring him to my ENT colleagues for further assessment and management advice.
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Cite this: Bell's Palsy: What to Know in Primary Care - Medscape - Mar 25, 2024.
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