Mobius syndrome

Historical Perspective:

Moebius syndrome (MS) is a rare congenital neurological condition that affects the muscle in the face and eye from birth. patients of this disease face problem in mouth moment including smiling, chewing and eye moment is also affected particularly sideways eye moments, except these facial issues problems with other body parts is also observed. A. Von Graefe, describe the first case of MS later detailed report about the condition and name was put forward by Paul Julius Moebius in 1888

Pathophysiology:

Patients with MS shows symptoms of paralysis of that facial nerve (CN VII) in about 96% of cases leading difficulties with facial movement such as swallowing, sucking, speaking and making facial expressions . Additionally eye movement nerve paralysis (CN VI) in approximatel85% of the cases resulting in problem with eye movement, dry eyes and various patterns of eyes abnormalities are observed that can help in understanding the physiological type of nerve damage. MS can cause with bone and muscular issues like club foot, fuse fingers and toes curved spines condition like kyphosis and and scoliosisThe exact pathophysiology of the disease is not clear; theories suggest that both genetic and environmental factors may contribute to the development of the diseases affecting the baby before birth. It is considered that around the sixth week of pregnancy, the fetus may not receive enough oxygen supply to the brain-stem, possibly and this due to blood flow problem in sub-clavian artery such as blood clot or narrowing of vessels. This may be linked to the used of certain drugs during pregnancy like misoprostolor or cocaine. The abnormal flow of blood could affect parts of the brain causing tissue damage, scarring and calcium buildup. However, the specific impact of blood flow on the sub-clavian artery and its effect on the facial and abducens nerves in MS is not fully understood .Other factor that could contribute to this disease is genetic it has been suggest that MS may be linked to abnormalities in two specific loci of chromosomes 3 and 10 and some cases of MS shows de-novo mutation in gene associated with the facial muscle weakness such as REV3L and PLXND1 .Other less common gene implicated in MS includes HOXA1, HOXB1, and TUBB3, In very few cases diseases appear to be inherited passed down from generation to generation.

Causes:

Due to multifaceted manifestation of the disease it is difficult to find out the exact cause of the disease however, some studies suggest some potential causes that mainly include genetic factor and Ischemic & Embryonic origin.

Genetic cause:

Some studies suggest that changes in certain genes are associated with MS these include PLXND1 and REV3L as well as homeobox genes such as HOXA1, HOXB1, and SOX14 which are found at certain area of chromosomes that are linked to the disease. These genes are responsible of development of facial and brain structures. Mostly MS cases are sporadic but there are some cases where it seems to run in families.

Ischemic & Embryonic Basis:

Some researchers believe that MS may be caused by issues during early fatal development, hypothesis suggest that abnormal blood flow or lack of blood flow to specific part of the body of developing fetus could be the key feature of the diseases that can lead to the MS.

Other Causes:

Some harmful substance such as teratogens like alcohol, cocaine and ergotamine as well as the drug thalidomide, misoprostol are the cause of the disease and in rare cases there is some consideration of linked between reproductive technologies and Moebius syndrome, a study suggest that as unusually shaped uterus of the mother like a unicornuate or bicornuate uterus may also linked to the diseases.

Epidemiology and Demographics :

A recent survey of the diseases suggests that about 0.3 out of every 100,000 babies are born

with MS.

Gender:

There is no difference of incidence among male and female.

Race:

No difference of diseases is observed in races.

Diagnosis:

To differentiate MS from other diseases various tests and imaging techniques are performed that help in diagnosis including electromyography (EMG), nerve conduction studies (NCS), ultrasound, MRI, genetic testing

EMG and NCS:

These tests help to distinguish diseases from other facial conditions that resembles to MS.

MRI:

It is helpful to find the clear image of cranial nerve and related structures revealing the absence of facial and abducens nerves which are the key sign of the MS Additionally other findings include an underdeveloped brain stem characterized by flattened floor of the fourth ventricle, calcification in the pons (specifically where the sixth cranial nerve nuclei are located), absence of normal structure of medulla and an underdeveloped cerebellum. These abnormalities in the brain stem, such as pons and medulla support the diagnosis of MS.

Diffusion tensor imaging (DTI):

It is highly sensitive imaging technique that helps to detect small abnormal areas in the brain which are the characteristics of the brain.

Polyhydramnios:

MS can sometime be diagnosed before birth through the presence of excess amniotic fluid and reduced fetal breathing movement and in this case genetic are performs

Treatment:

MS affects multiple aspects of a patient’s health therefore a team of specialist is required to ensure that each and every problem is properly identified and treated in a well manner, minimizing the risk of worsening the patients overall health.

Tracheostomy:

Patients with MS often experience difficulty in swallowing and breathing. They may be treated with specialized diet and if necessary, a tracheostomy to resolve the breathing related issues

Smile surgery:

In order to improve facial movement particularly the ability to smile surgery intervention may be used this involve using muscles from the leg to restore facial movement this muscle is connected to the facial nerve that help in smile

Rehabilitation techniques:

FIT-SAT is a neurorehabilitation technique use special exercise that helps to improve patient’s smile this can be done at hope through audio or visual tool

Tarsorrhaphy:

MS patients often experience issues with eye and it surrounding such as an inability to close the eyelids completely, which can lead to dry eyes, ulcers and infections usually this condition is treated with the lubricanmts but surgery is also offered to improve eyelid movement a small gold weight placed in the upper eyelid and sometime muscle graph is also use useful to close the eyelid and issue with the lower eyelid is resolved through tarsorrhaphy

Botulinum Toxin Injections:

To prevent muscle tightening and eye alignment botox is used in eye muscles to help with eye movement affected by nerve palsy.

Surgical option for eye alignment:

Treatment options include Medial Rectus Recession, Lateral Rectus Resection, Muscle Transposition and Double-Augmented Vertical Recti Transposition are helpful to improve eye movement and alignment