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 co-morbidities. 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 (in relation to the situation given and the picture shown)
1. Frontalis
Action: Elevates the eyebrows and wrinkles the forehead
Effect: Patient may have difficulty in raising eyebrow or forehead on the affected side
2. Orbicularis Oculi
Action: Closes the eyelids (blinking)
Effect: Patient may have difficulty closing his or her eyelids, may lead to inability to close eyelids completely.
3. Orbicularis Oris
Action: Closes and protrudes lips (kissing), compress lips against teeth, shapes lips during speech
Effect: Patient may have difficulty in controlling his or her mouth. Closing the mouth completely could be difficult and may result in drooling.
4.Zygomaticus major muscle
Action: Laterally elevates and draws corner of mouth
Effect: Patient may have difficulty in smiling or lifting the side of the mouth that rests on the affected side. Patient’s smile will appear asymmetrical
5.Buccinator
Action: Laterally pulls corner of mouth, presses cheek against teeth
Effect: Patients may have difficulty in chewing, blowing and sucking, which may result in food being accumulated on the cheek area of the mouth. Physical breakdown of food is affected.
Mechanism of muscle weakness:
Bell’s palsy is a neurological disorder that is driven by the inflammation of the facial nerve, specifically the seventh cranial nerve which mainly controls the muscles of our face. Due to the inflammation of the nerves, transmission of nerve impulses that carry out facial expressions or mechanisms are disrupted, thus resulting in muscle weakness.
Other symptoms
1. Difficulty in speaking
-Difficulty in forming sounds, pronouncing words may signify muscle weakness in the mouth or cheek area.
2.Losing sense of taste
-Losing the sense of taste may also signify muscle weakness as facial muscles are associated with taste fibers in the tongue.
3.Hyperacusis (Unequal sounds heard in both ears)
-Hyperacusis means having one ear hear louder sounds than the other. Experiencing this signifies that the weakening of facial muscles have affected and weakened your Stapedius muscles–muscle that regulates intensity of sounds in your ears.
4.Difficulty in smiling
-As mentioned above, difficulty in smiling signifies weakness in the zygomaticus major muscle.
5.Difficulty in closing one eye
-As mentioned above, difficulty in closing one eye signifies weakness in the orbicularis oculi.