This is patient AM, 28-year-old male who came in the ER because of drooping of his left face. He said he woke up and he could not move his left face.
He has no other muscle weakness. He is conscious and coherent although he had a little difficulty speaking because the left side of his lips drooped. He had normal blood pressure and he had no other comorbidities. He was diagnosed to have Bell’s palsy. Name 5 muscles which are affected and list its actions. Describe the mechanism of his muscle weakness. What other symptoms could the patient exhibit as a result of facial muscle weakness?
Bell's palsy is a disorder that results in an abrupt weakening in one side of the face's muscles. Usually, the weakness is transient and gets better over a few weeks. The weakening gives the face a drooping appearance on half of it (Bell’s Palsy - Symptoms and Causes - Mayo Clinic, 2024).
Five (5) Affected Muscles and Their Actions:
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Frontalis
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Action: Raises the eyebrows and wrinkles the forehead.
Orbicularis Oculi
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Action: Closes the eyelids and assists in blinking and winking.
Orbicularis Oris
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Action: Closes and protrudes the lips, as well as aids in articulation.
Buccinator
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Action: Compresses the cheek against the teeth, helps in blowing and chewing.
Zygomaticus Major
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Action: Elevates the corner of the mouth, contributing to smiling.
Mechanism of Muscle Weakness:
The facial nerve (cranial nerve VII) controls the muscles of facial expression. Bell’s palsy typically results from:
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Inflammation or compression of the facial nerve: Impairs or damages the nerve's ability to transmit signals to the facial muscles, leading to weakness or paralysis.
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Edema: Swelling in the nerve’s path that can lead to disrupt its function.
In Bell’s palsy, the nerve inflammation often causes sudden onset facial muscle weakness or paralysis on one side of the face, which might affect the mentioned muscles.
Other Symptoms Due to Facial Muscle Weakness:
According to an article released in 2024 by John Hopkins Medicine, here are some other symptoms of the said condition:
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Inability to close the eye on the affected side: This can lead to dryness or irritation of the eye.
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Difficulty with facial expressions: Issues with smiling, frowning, or other expressions on the affected side.
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Drooling: Difficulty controlling the mouth and lips can result in drooling.
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Altered taste: Loss of taste sensation on the anterior two-thirds of the tongue on the affected side.
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Increased sensitivity to sound: Hyperacusis due to paralysis of the stapedius muscle, which normally dampens loud sounds.
Reference/s:
Bell’s Palsy. (2024, May 14). Johns Hopkins Medicine. https://www.hopkinsmedicine.org/health/conditions-and-diseases/bells-palsy
Bell’s palsy - Symptoms and causes - Mayo Clinic. (2024, March 15). Mayo Clinic. https://www.mayoclinic.org/diseases-conditions/bells-palsy/symptoms-causes/syc-20370028