Mobius syndrome

Moebius syndrome: Congenital facial diplegia

Share this
Advertisement

Other Names for this Condition 

• Congenital facial diplegia

• Congenital ophthalmoplegia and facial paresis

• Mobius syndrome

• Moebius congenital oculofacial paralysis

• Moebius sequence

• Moebius spectrum

• Möbius sequence

Moebius syndrome

Paul Julius Moebius, a German neurologist, in 1892 was the first to describe this condition. This anomaly is also been described as congenital facial diplegia, congenital oculofacial paralysis, nuclear agenesis and congenital nuclear aplasia.

Moebius Syndrome (MS) (OMIM 157900), previously known as Moebius syndrome, is a rare disorder defined by congenital paralysis of the 6th and 7th cranial nerves. The disorder is congenital with chronic consequences and is previously diagnosed after birth or during early infancy by the child’s facial features. Paralysis of other cranial nerves, malformations of orofacial structures, and limb anomalies may also be present. The incidence of MS varies from 0.00002 to 0.002%, with a sex ratio of 1:1, although a Swedish study found a female-male-ratio of 1:3 and a high occurrence of misdiagnosis.

Many people with Moebius syndrome are born with a small chin (micrognathia) and a small mouth (microstomia) with a short or unusually shaped tongue. The roof of the mouth may have an abnormal opening (cleft palate) or be high and arched. These abnormalities contribute to problems with speech, which occur in many children with Moebius syndrome. Dental abnormalities, including missing and misaligned teeth, are also common.

Moebius syndrome also affects muscles that control back-and-forth eye movement. Affected individuals must move their head from side to side to read or follow the movement of objects. People with this disorder have difficulty making eye contact, and their eyes may not look in the same direction (strabismus). Additionally, the eyelids may not close completely when blinking or sleeping, which can result in dry or irritated eyes.

Other features of Moebius syndrome can include bone abnormalities in the hands and feet, weak muscle tone (hypotonia), and hearing loss. Affected children often experience delayed development of motor skills (such as crawling and walking), although most eventually acquire these skills.

Causes

The causes of Moebius syndrome are unknown, although the condition probably results from a combination of environmental and genetic factors. Researchers are working to identify and describe specific genes related to this condition. The disorder appears to be associated with changes in particular regions of chromosomes 3, 10, or 13 in some families. Certain medications taken during pregnancy and abuse of drugs such as cocaine may also be risk factors for Moebius syndrome.

Many of the signs and symptoms of Moebius syndrome result from the absence or underdevelopment of cranial nerves VI and VII. These nerves, which emerge from the brainstem at the back of the brain, control back-and-forth eye movement and facial expressions. The disorder can also affect other cranial nerves that are important for speech, chewing, and swallowing. Abnormal development of cranial nerves leads to the facial muscle weakness or paralysis that is characteristic of Moebius syndrome.

Researchers speculate that Moebius syndrome may result from changes in blood flow to the brainstem during early stages of embryonic development. However, it is unclear what causes these changes to occur and why they specifically disrupt the development of cranial nerves VI and VII. Even less is known about the causes of some other signs and symptoms of this condition, including hand and foot abnormalities.

Cranial nerves

Complications

Speech and Feeding Problems

Cranial nerves 5,9,10 and 12 can also be affected in Moebius syndrome. These are the nerves that control the muscles of the jaw, tongue, throat and larynx and help produce speech. Abnormalities of these nerves and muscles may lead to articulation, voice and resonance problems. An experienced speech pathologist and otolaryngologist (ear nose and throat specialist) can help with your child’s voice problems.

Many of the nerves and muscles that produce speech are also responsible for chewing and swallowing. Children with Moebius syndrome may have difficulty sucking soon after birth. Infants with swallowing problems may aspirate (inhale) small amounts of food or liquid. Frequent aspiration can lead to pneumonia. Most of the feeding problems seen in Moebius syndrome improve as the child develops improved motor control of the muscles responsible for swallowing. Some children may require a feeding tube placed through the nose or stomach to improve nutrition if the feeding problems are severe.

Dental Problems

Because of the tongue movement abnormalities seen in Moebius syndrome, food may accumulate behind the teeth and cause decay

Advertisement
. Careful dental hygiene with frequent tooth brushing and flossing will help prevent the buildup of food and protect the teeth and gums. If your child has a cleft palate in addition to Moebius syndrome, they may require orthodontics to align the teeth and jaws when he/she is an adolescent.

Hearing Loss

As hearing problems can be present in children with Moebius syndrome, it is important to have your child’s hearing tested early in life. If your child has a cleft palate in addition to Moebius syndrome he/she may experience frequent ear infections (otitis media), which, if untreated, can contribute to hearing loss. Pressure equalizing tubes may be placed in the ear drums to reduce the risk of hearing loss.

Intellectual Development

Most persons with Moebius syndrome have normal intelligence. A small percentage of people with Moebius syndrome have mental retardation.

Cleft Palate

Some children with Moebius syndrome are born with a cleft palate. A cleft palate is an opening in the hard or soft portion of the roof of the mouth. The opening should be surgically closed at around 10 to12 months of age. A cleft palate decreases an infant’s ability to suck which can contribute to early feeding problems. In addition, the opening in the roof of the mouth allows for the passage of food and liquid out of the nose. Fortunately, cleft-related feeding problems usually improve soon after birth with proper positioning during feeding and the use of special nipples. A feeding specialist can help teach you how to feed your child.

Treatment

A multidisciplinary team approach through a Craniofacial Center is often the most effective way to treat Moebius syndrome. Specialists, including neurologists, ophthalmologists, plastic surgeons, otolaryngologists (ear, nose and throat specialists) and speech pathologists familiar with Moebius syndrome may be required for your child’s medical care. Infants sometimes require special bottles (i.e., Haberman Feeder) or feeding tubes to maintain sufficient nutrition. Strabismus (crossed eyes) is usually correctable with surgery.

Children with Moebius syndrome can also benefit from physical and speech therapy to improve their gross motor skills and coordination, and to gain better control over speaking and eating. Limb and jaw deformities may often be improved through surgery. In addition, reconstructive surgery of the face can offer benefits in individual cases. In some cases, nerve and muscle transfers to the corners of the mouth have been performed to provide the ability to smile.

Reference

Briegel W, Schimek M, Kamp-Becker I. Moebius sequence and autism spectrumdisorders–less frequently associated than formerly thought. Res Dev Disabil.2010 Nov-Dec;31(6):1462-6. doi: 10.1016/j.ridd.2010.06.012. Citation on PubMed (https://www.ncbi.nlm.nih.gov/pubmed/20621443)

Briegel W, Schimek M, Knapp D, Holderbach R, Wenzel P, Knapp EM. Cognitiveevaluation in children and adolescents with Möbius sequence. Child Care HealthDev. 2009 Sep;35(5):650-5. doi: 10.1111/j.1365-2214.2009.00943.x. Epub 2009 Feb23. Citation on PubMed (https://www.ncbi.nlm.nih.gov/pubmed/19250253)

Broussard AB, Borazjani JG. The faces of Moebius syndrome: recognition andanticipatory guidance. MCN Am J Matern Child Nurs. 2008 Sep-Oct;33(5):272-8; quiz279-80. doi: 10.1097/01.NMC.0000334892.45979.d5. Review. Citation on PubMed (https://www.ncbi.nlm.nih.gov/pubmed/18758328)

Children's Craniofacial Association: A Guide to Understanding Moebius Syndrome (https://ccakids.org//assets/syndromebk_moebius-guide_2015.pdf)

Verzijl HT, Padberg GW, Zwarts MJ. The spectrum of Mobius syndrome: anelectrophysiological study. Brain. 2005 Jul;128(Pt 7):1728-36. Epub 2005 Apr 13. Citation on PubMed (https://www.ncbi.nlm.nih.gov/pubmed/15829555)

Verzijl HT, van der Zwaag B, Cruysberg JR, Padberg GW. Möbius syndromeredefined: a syndrome of rhombencephalic maldevelopment. Neurology. 2003 Aug12;61(3):327-33. Citation on PubMed (https://www.ncbi.nlm.nih.gov/pubme d/12913192)

Kim N, Kim JH, Kim JS, Hwang JM. Mobius syndrome: clinico-radiologic correlation. Graefes Arch Clin Exp Ophthalmol 2018;256:2219-2223

Pedraza S, Gamez J, Rovira A, et al. MRI findings in Mobius syndrome: correlation with clinical features. Neurology 2000;55:1058-1060

Saint-Martin C, Clapuyt P, Duprez T, Ghariani S, Verellen G. Mobius sequence and severe pons hypoplasia: a case report. Pediatr Radiol 1998;28:932

Kuhn MJ, Clark HB, Morales A, Shekar PC. Group III Mobius syndrome: CT and MR findings. AJNR Am J Neuroradiol 1990;11:903-904

Verzijl HT, Valk J, de Vries R, Padberg GW. Radiologic evidence for absence of the facial nerve in Mobius syndrome. Neurology 2005;64:849-855

Share this

Leave a Comment

Your email address will not be published. Required fields are marked *

error: Content is protected !!