Facial paralysis
The facial musculature is supplied by the brain, and subsequently also by the facial nerve (the seventh of the twelve cranial nerves, also called the seventh cranial nerve). A disturbance in either of these areas results in weakness of the facial musculature, which is mainly noticeable by drooping at the corner of the mouth. The eyelid may be more or less affected. If the facial nerve is affected in isolation, the eye cannot be closed completely at all. Usually only one side of the face is affected, bilateral paralysis is rare.
Cause
The cause of isolated facial paralysis is usually harmless inflammation of the affected facial nerve, for example due to a simple viral infection. The facial paralysis in these cases is comparatively harmless, but very annoying. It very often regresses completely, but this can take several weeks in severe cases. Especially in cases of incomplete eye closure, care must be taken to prevent the cornea drying out. In rarer cases, this facial paralysis is also a sign of a more serious problem, such as a fracture of the temporal bones or the base of the skull, or a tumour within the head. Therefore, an MRI examination is usually necessary
Facial paralysis may also be caused by damage to the responsible centre in the brain, and in these cases it usually occurs at the same time as arm or leg weakness, clumsiness in the hand, which also occur suddenly, for example due to a stroke, a cerebral haemorrhage or a tumour.
