Activity 4
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?
Muscles affected by Bell’s palsy and their actions:
-
Frontalis - Draws scalp anteriorly, raises eyebrow, and wrinkles the skin of the forehead horizontally
-
Platysma - Draws outer part of lower lip inferiorly and posteriorly; depresses the mandible
-
Orbicularis oris - Closes and protrudes lips; compresses lips against the teeth
-
Orbicularis oculi - Closes eyes
-
Buccinator - Presses cheeks against teeth and lips; draws corner of the mouth laterally; assists in mastication.
Bell’s palsy is a paralysis of the facial muscles due to damage or disease of the facial (VII) nerve. Its exact cause is unknown. However, experts think that Bell’s palsy is acquired due to an inflammation of the facial nerve due to infection. Bell’s palsy mimics the symptoms of stroke: drooped entire side of the face, inability to close eyes, and wrinkle the forehead. Other symptoms that patients may experience as a result of facial muscle weakness and Bell’s palsy are: pain around the jaw or behind the ear, dry eyes, headache, tinnitus, and loss of taste.