Moebius syndrome is a rare neurological disorder where people are unable to smile, frown, pucker their lips, raise eyebrows, or close eyelids.
The condition can affect several cranial nerves, especially those that control the muscles of the face. In most of the cases, the sixth and seventh cranial nerves are missing from birth (1).
The absence of these particular nerves leads to the characteristic facial paralysis and other associated symptoms of Moebius syndrome.
Congenital facial and abducens palsy was first described by Von Graefe (1880) and Moebius (1888), a German neurologist after whom the syndrome was later named.
In this article, you will learn about symptoms, causes, diagnosis, and treatments, linked with Moebius syndrome.
Moebius syndrome symptoms depend on which nerve is affected. The signs and symptoms of this disease are apparent from birth(congenital).
The most common signs of Moebius syndrome are:
- Facial paralysis (palsy).
- Children with Moebius syndrome can’t smile or frown.
- Micrognatia – Condition where the chin is undersized (2).
- Microstomia – Term used to describe the size and shape of the oral aperture (3).
- Short tongue.
- The mouth roof may have an unusual opening (cleft palate) or be high and arched (4, 5).
- Problems with speech, particularly in children.
- Dental abnormalities, which includes missing and misaligned teeth.
- Affects muscles that control back-and-forth eye movement.
- Bone abnormalities in the hands and feet.
- Weak muscle tone (hypotonia).
- Hearing loss, in case specific cranial nerves are affected.
- Crossed eyes (strabismus).
- Weak muscle tone (hypotonia).
- The webbing of the hands or feet (syndactyly).
- Abnormal curvature of the spine (scoliosis).
- Respiratory disorders.
- Sleep problems.
- Upper body weakness which delays in motor function.
- Ear abnormalities that may result in frequent or persistent ear infections (otitis media)
- Skeletal abnormalities of the feet, hands, and limbs (club feet).
- Other disorders are speech, swallowing, and vision.
- Underdeveloped chest walls muscles.
- Cannot move their eyes together to track an object. They will need to turn their head to follow an object fully.
Most people living with this rare syndrome don’t have intellectual disability. Assumptions are made due to their physical challenge to speak and unique facial characteristics.
Moebius Syndrome Causes:
The exact cause of Moebius syndrome is still unknown. It is most likely caused by various factors. Environmental exposures and genetics have been associated in some studies, but more research is required.
The majority of Moebius syndrome cases change randomly (sporadic) in people with no family history of the disorder (6).
Scientists are working to identify and describe specific genes related to this condition. The syndrome appears to be related to changes in specific regions of chromosomes in families (7).
Certain medications taken at the time pregnancy and abuse of drugs like cocaine may also be risk factors for Moebius syndrome.
Many of the symptoms of Moebius syndrome result from the absence or underdevelopment of cranial nerves VI and VII.
These nerves emerge from the brainstem at the back of the brain. They control back-and-forth eye movement and facial expressions (8).
The condition can also affect other cranial nerves that are vital for speech, chewing, and swallowing. Abnormal development of cranial nerves results in facial muscle weakness or paralysis that is characteristic of Moebius syndrome.
Experts speculate that Moebius syndrome may result from changes in blood flow to the brainstem during the early stages of embryonic development.
However, it is not clear what causes these changes to occur and why they purposely disrupt the progress of cranial nerves VI and VII.
Much less is known about the causes of some other signs and symptoms of this disorder, including hand and foot abnormalities.
There isn’t any particular test to diagnose Moebius syndrome. Since the disorder is present at birth, it can usually be diagnosed during an in-depth newborn exam. While specific manifestations depend on the cranial nerves that are underdeveloped or missing, there are three diagnostic norms to make a diagnosis of Moebius syndrome:
- Weakness or paralysis of at least one side of the face (usually both).
- Lateral movement of the eyes is paralyzed.
- Vertical eyes movement is intact.
Researches may perform more specialized testing like neurological or ophthalmologic exams to rule out other conditions that can lead to facial paralysis and other symptoms of Moebius syndrome.
It’s essential that correct diagnosis is made soon after birth. Kids with Moebius Syndrome typically need to work with a team of health specialists. The earlier intervention and care teams are gathered, the better the long-term outcomes for patients.
While Moebius Syndrome isn’t progressive, the nature of the symptoms can present significant challenges for each patient individually. The factors depend on the specific nerves affected, the severity of the condition, availability of swift diagnosis, treatment, and supportive resources.
Moebius Syndrome Treatment:
Each person born with Moebius syndrome will have different problems. While there’s no decisive treatment or cure for the disorder, a team of experts can take care of those suffering from Moebius syndrome.
Since the diagnosis can be made at birth or soon after, early interventions, like physical, occupational, and speech therapy, can be made quickly. A regular eye exam and the ongoing support of an ophthalmologist can help to address vision problems. If the hearing is impaired, an audiologist may be consulted.
Other professionals that may be involved in care include:
- War, nose and throat consultants.
- Respiratory specialists.
- Pediatricians and pediatric physicians.
- Maxillofacial specialists.
- Plastic surgeons.
If the symptoms are severe, then surgery might be needed. In some cases, nerves graft from other parts of the body to replace the missing cranial nerves might be possible.
Other surgical measures that may be necessary include:
- Eye or eyelid surgery to improve vision and correct strabismus.
- Oral surgery to address dental issues.
- Orthopedic procedures (or nonsurgical interventions like splinting) to improve mobility.
- Braces or surgery to correct the problem scoliosis.
This procedure involves taking a nerve from the thigh and grafting it to the face, particularly to the muscles that help an individual to chew (masseter).
The operation has amended facial mobility and speech for some patients with Moebius syndrome. It includes successfully restoring the ability to make certain facial expressions, like smiling.
Moebius Syndrome is usually diagnosed at birth. Hence quick diagnosis and treatment are essential to ensure a person with the disorder gets the necessary support.
Some children with this rare syndrome may have motor or speech delays. They are usually a result of physical symptoms related to the mouth or muscles of the limbs.
In some instances, the underdeveloped muscles of the chest are associated with another condition known as Poland syndrome (9). The person with Poland syndrome is missing part of one of the big muscles of the chest (pectoralis major).
Patients who diagnosed with Poland syndrome, cosmetic surgery process to correct structural abnormalities of the chest wall, including breast tissue, can be done in many cases
Most of the people with Moebius syndrome don’t have any intellectual delays. Some research also indicated children with Moebius syndrome are more likely to have autism spectrum disorders (10).
Research And Progress:
The first case of the congenital facial diplegia syndrome, also known as Moebius syndrome, was that of Von Graefe (1880).
Moebius, a German neurologist, described this case in 1888, and after whom the syndrome was later named.
While there is no conclusive treatment or cure, but proper care and treatment can give many people a normal life expectancy. There are a variety of options, including physical therapy and specialized surgery.
The Moebius Syndrome Foundation conducts clinical trials that can help prevent, detect, and treat these diseases and disorders (11).
Specialists are working to uncover as many aspects of Moebius syndrome and other related disorders.
Therefore, the chances are that medical experts will be able to find a cure for Moebius Syndrome very soon.
Launched in 2019, Moebius Syndrome Awareness Day(MSAD) is the international campaign by Moebius Syndrome Foundation.
People will celebrate Moebius Syndrome Awareness Day on January 24 each year by wearing purple and hosting informational events.