Several conditions can cause facial paralysis. Congenital causes include Mobius syndrome, Melkersson-Rosenthal syndrome, hemifacial microsomia and trauma during birth. Mobius syndrome involves dysfunction of the abducens and facial nerves, resulting in difficulty in expressing emotions and lack of facial movement.
The New York Eye and Ear Infirmary noted that patients with this disorder can experience social isolation, oral incompetence, low self-esteem and drooling.
With Melkersson-Rosenthal syndrome, patients experience tongue fissures and facial swelling with the facial paralysis. A patient who has hemifacial microsomia has one side of the face that is not as developed as the other half.
The most common cause of facial paralysis is Bell’s palsy, which affects 30 people per 100,000, according to the New York Eye and Ear Infirmary. A stroke can also cause facial paralysis, though other muscles on the same side of the body can also become affected.
Certain infections can result in facial paralysis.