Bell’s palsy is, by far, the most common cause of acute facial paralysis, and has thus been studied extensively. Far less is known, however, about the very rare Moebius syndrome, which causes severe bilateral facial paralysis and is examined in somewhat deeper detail on this page.
Moebius syndrome is characterised by an underdeveloped VII cranial nerve, a problem which is present at birth. It can also affect the nerves of the face and the facial nerve. Its causes are, as yet, unknown, but some theories suggest that the syndrome is a result of disrupted blood supply to the nerves in the embryo, or that there may be a general malfunction in the development of the nerves and brain during critical development cycles in the womb. Other theories suggest that Moebius syndrome may be caused by certain drugs taken during pregnancy.
An individual born with Moebius syndrome is unable to move his or her face, or at least part of the face, making it impossible to smile, frown or blink. It can affect both sides of the face, but not in all cases. The effects may be asymmetrical and their severity varies between total paralysis and slight movement impairment. The individual may also not be able to hear, cough, speak clearly or swallow.
Like all disorders that cause facial disfigurements, Moebius syndrome can be difficult to live with and accept, especially for young children. Symptomatic treatments are available, however, and the first priority is to ensure that children eat well in order to develop properly. Speech therapy can assist in reducing slurring and can help with eating and drooling too. Surgery can help to correct a squint and when the child is older, it is possible to join the facial muscles to working nerves in order to create a smile.
Moebius syndrome is certainly one of the rarest causes of facial paralysis and before diagnosis can be made, causes like injury, infection, stroke and Bell’s palsy first need to be ruled out.