Duration
The duration of facial nerve palsy depends on various factors, so no general statement can be made about it. In most cases, facial nerve palsy occurs idiopathically, so no coherent cause can be found.If it is noticed early by those affected, it can be quickly treated with Prednisolone for 5-10 days. As a result, about 80% of all affected persons will be completely cured, which means that the treatment will take about 2-3 weeks.
Occasionally, however, the therapy does not work at all or only insufficiently. If there is no improvement within the first three weeks after the start of therapy, this has an unfavorable effect on the prognosis, which also prolongs the duration of facial nerve palsy. Further unfavorable factors that increase the duration of facial nerve palsy are the occurrence of the disease at an advanced age and the presence of a complete paresis of the nerve. Furthermore, in the case of other causes, such as an infection, trauma or tumor, the duration depends on how well the respective cause can be treated. Depending on the cause, medication or even surgical methods are available.
Prognosis
The prognosis of facial nerve palsy depends on the underlying cause. In the so-called idiopathic facial nerve palsy, where no exact cause can be found and which accounts for about 70% of all cases, the chance of a complete cure is 80%. Occasionally, the therapy does not work at all or only inadequately, leaving permanent damage caused by facial nerve palsy.
In most cases, however, a quite normal life can be led despite the weakened muscles. Occasionally there is a faulty re-growth of the nerve after damage. This can cause so-called crocodile tears to appear, for example, and those affected get tears in their eyes while eating, due to the connection between the tear and salivary glands.
Causes
The causes of facial nerve palsy are very different. In fact, it remains unexplained in about 70% of all cases. This is also called idiopathic.
It comes to a sudden occurrence of facial nerve paresis without an explainable connection being found. Now and then, however, a cause can be identified as such. Frequently, inflammation is responsible for facial nerve palsy, usually due to an infection with a pathogen.
Lyme disease is probably the best known infection, which occurs mainly in children. It is then also called neuroborreliosis, as a nerve is affected. But also a herpes zoster infection can be a possible cause.
In the so-called Ramsay-Hunt syndrome caused by the herpes viruses, there is a zoster oticus, a painful rash in the area of the auditory canal, with ear pain and facial paresis. In very rare cases, tuberculosis or syphilis can cause facial paresis. Mechanical injuries to the nerve, for example during dental treatment or due to a broken bone, can also lead to paralysis of the cranial nerve.
Furthermore, tumors, for example of the parotid gland, diabetes mellitus, Guillain-Barré syndrome or a complicated inflammation of the middle ear can occasionally be the cause of facial nerve palsy. Very rarely, facial paresis can also occur after dental treatment. The reason for this is that many dental treatments require a local anesthetic.
This is also called conduction anesthesia, because it is usually placed in the area of a nerve in such a way that its conduction temporarily stops working for a certain section. If the facial nerve is accidentally damaged, this can lead to facial paresis. This occurs either immediately or after a few days and should be treated as soon as possible. The symptoms often improve as soon as the effect of the anesthetic wears off.
