Presentation of Möbius syndrome
The injury can affect the facial muscles and the ocular muscle on one side or on both sides, and to varying degrees. Other cranial nerves may be affected as well, usually the nerve that controls the tongue muscles, but both the nerve that controls swallowing and the one that controls chewing muscles may also be impacted. Some children are born with a cleft palate, which requires specific measures and surgery. Regarding the different kinds of muscle paralysis that occur, the consequences include not only impact on the ocular muscles, but also impaired facial motor control and facial expressions, as well as impaired oral motor control, affecting the person’s ability to speak and articulate.
In a Swedish hospital/habilitation based study, comprising 25 individuals, almost half had congenital skeletal malformations in their upper and/or lower extremities. There are also cases of congenital malformations of hands, e.g. ones where the person’s fingers grow together. Patients may also suffer from a condition named Poland syndrome, which involves under-developed thoracic muscles in combination with congenital hand malformation. In cases of congenital malformation of the lower extremities, the patient may also have congenital toe malformations as well as so-called clubfoot.
The symptomatic presentation varies greatly between different individuals with Möbius syndrome, firstly based on the degree and type of cranial nerve impact and if there are any concurrent congenital malformations of extremities, and secondly depending on whether any cognitive disorders and mental retardation are present. Most affected individuals with Möbius syndrome, however, have normal intelligence.
Because it also affects the muscles that control eye-movement, it can be difficult for individuals suffering from Möbius syndrome to make eye contact; it can also be difficult for them to follow movement with their eyes, or to keep their eyes facing the same direction resulting in strabismus. It can even be difficult for them to blink or completely close their eyes, which can lead to eye irritation or dryness.