What is Marcus Gunn Jaw-Winking Syndrome?
Marcus Gunn jaw-winking syndrome (MGJWS), or simply called Marcus-Gunn syndrome, is a condition often seen in those born with a droopy eyelid, also known as blepharoptosis. This syndrome was first identified by a Scottish eye doctor named Robert Marcus Gunn back in 1883, who observed it in a 15-year-old girl. The condition involved one side of her eyelid drooping but contracting, or twitching, when she moved her upper eyelid.
Apart from MGJWS, this condition is also known by various other names such as Marcus-Gunn jaw winking phenomenon (MGP), Marcus Gunn ptosis, Marcus Gunn jaw winking trigemino-oculomotor synkinesis, Maxillopalpebral synkinesis, and Pterygoid-levator synkinesis. It’s part of a group of disorders seen at birth that affect cranial nerves, which are the nerves that come directly from your brain. These disorders are called congenital cranial dysinnervation disorders (CCDD). People with this condition have varying degrees of droopy eyelid in the relaxed position.
Interestingly, what sets Marcus-Gunn syndrome apart is that the upper eyelid movements are in sync with jaw movements, like when chewing food. It usually affects only one eyelid but can, in some cases, affect both.
What Causes Marcus Gunn Jaw-Winking Syndrome?
Synkinesis is when muscles, controlled by the same nerve or different nerves, move together in a coordinated sequence. Marcus Gunn jaw-winking syndrome (MGJWS) is one such example. In this condition, an unusual connection between nerves causes the upper eyelid and the jaw to move together. Specifically, the abnormal connection links parts of the trigeminal nerve (that controls facial sensation and jaw movements) and the oculomotor nerve (that manages eye movements).
MGJWS is present from birth and the unusual nerve connection is thought to happen due to fibers of the fifth cranial nerve (or trigeminal nerve), which are directly or indirectly controlling the muscle that lifts the eyelid. This is a rare condition, and while it can sometimes run in families, cases acquired later in life are often associated with complex eye surgery or trauma.
Risk Factors and Frequency for Marcus Gunn Jaw-Winking Syndrome
Blepharoptosis, a condition that causes droopy eyelids, is congenital, or present at birth, in about 50% of cases. A specific condition named Marcus Gunn jaw-winking syndrome (MGJWS), which can cause abnormal eye movements while moving the jaw, occurs in about 2%-13% of individuals with congenital blepharoptosis. Although MGJWS can be present at birth, it can show up at any age.
- Most cases of MGJWS are unilateral, meaning they affect one side, and often, it’s the left side.
- However, there have been cases where both sides are affected.
- There is no gender preference for MGJWS – it affects males and females equally.
Signs and Symptoms of Marcus Gunn Jaw-Winking Syndrome
The Marcus Gunn jaw-winking syndrome (MGJWS) entails a brief upward movement of the upper eyelid, followed by a quick drop. It’s noticeable when the person with this condition opens their mouth, moves their jaw to the other side, chews, or sucks. People with this syndrome may also have lazy eyes, crossed eyes, or weak muscles in their superior rectus (which helps us look upward).
A small percentage of patients may have uneven focus between their two eyes. Between 30% to 60% may have a lazy eye, which could be due to a droopy eyelid, uneven focus, or crossed eyes. Rare cases may show additional symptoms. An individual may also have a cleft lip or palate, nasal sensory nerve issues, and growth and development abnormalities. This syndrome is first noticed in babies when breastfeeding or bottle-feeding.
This condition may be confirmed if the following signs are present:
- One eyelid is drooped
- The upper eyelid moves during activities that involve the mouth or jaw
- The affected eye may show a downward movement
An eye examination for this condition might include several tests:
- Checking vision
- Examining the pupil’s reaction to light
- Evaluating the focus of the lens
- Testing the movement of the eye muscles
- Observing the “Bell phenomenon” – an automatic upward movement of the eyes when the lids close
- Checking if the child lifts their chin to see better due to a drooping eyelid
The degree of the drooping eyelid should be checked while the jaw is kept steady. It might be mild (up to 2mm), moderate (3mm), or severe (at least 4mm). The distance between the upper and lower eyelids should also be measured, together with the reflex of the eye in response to light in the normal gaze position (MRD1) and the extreme upward gaze (MRD3). Another key indicator is the ‘levator function’, or movement of the upper lid from down to up while the forehead is held steady.
Testing for Marcus Gunn Jaw-Winking Syndrome
If a patient needs surgery for drooping eyelids (ptosis), doctors need to first make sure that the patient hasn’t also got dry eyes. This is important because dry eyes can complicate the surgery. In order to prepare for surgery, the patient might have to get a complete blood test, and a chest x-ray. These tests help give the doctors a better understanding of the patient’s overall health before the operation.
For patients with a condition called Marcus Gunn jaw-winking syndrome, an ECG (a test that checks your heart rhythm) should be done. These patients are more likely to have irregular heart rhythms, known as cardiac arrhythmias.
Lastly, it is very important that the anesthesiologist (doctor who provides anesthesia for the surgery) is made aware of the patient’s medical diagnosis before the surgery starts. This allows them to prepare for any complications that might arise during the operation.
Treatment Options for Marcus Gunn Jaw-Winking Syndrome
For those with Marcus Gunn jaw-winking syndrome (MGJWS), there are a few different treatment options that they might consider.
Medical Care
If the patient is encountering weak or blurred vision known as amblyopia, then they need to be treated as quickly as possible. This might involve occlusion therapy (where one eye is either partially or fully covered to improve the weaker eye) or correcting anisometropia (which is the difference in refractive power between the two eyes). It’s important to have regular check-ups while undergoing therapy for amblyopia. Clinical photographs might also be used to keep track of the patient’s progress.
Surgical Care
The approach towards surgery for MGJWS presents some controversy. Some surgeons believe that children shouldn’t undergo surgery until they are around one or two years old, when the use of general anesthesia is safer. It’s also important to note that surgical correction that addresses only ptosis (drooping of the upper eyelid) without fixing the unusual eyelid movement that occurs when the jaw moves could worsen the eyelid movement. This could potentially result in a cosmetic disfigurement for the patient. Deciding on the need for surgery depends on a few different factors like the presence of amblyopia and vertical squinting, severe ptosis with or without levator muscle dysfunction (levator muscles are responsible for lifting the upper eyelid).
The unusual eyelid movements caused by MGJWS are often only a cosmetic concern if they’re 2 mm or more. If the unusual eyelid movement is not significantly noticeable or if the ptosis is mild, it’s usually best not to have surgery. But if the patient desires correction for mild ptosis, then certain procedures like Muller muscle and conjunctival resection, a Fasanella– Servat procedure, or a standard external levator resection might be recommended.
For a moderate to severe ptosis, then a surgical treatment known as resection of LPS with bilateral frontalis suspension could be an option. This procedure offers good results in eliminating unusual eyelid movement and improving bilateral symmetry. Some surgeons suggest doing more resection than normal to avoid complications. In cases of severe ptosis, a maximum levator resection with frontalis suspension is necessary.
Keep in mind, there are a few conditions that may make surgical treatment of MGJWS less favorable, such as poor Bell phenomena (a protective mechanism where your eye rolls upwards when you close your eyes), reduced corneal sensations (decreased feeling in the front surface of the eye), and dry eyes. All of these could lead to a risk of exposure keratitis, a disease that damages the front surface of the eye, threatening vision.
What else can Marcus Gunn Jaw-Winking Syndrome be?
Marcus Gunn jaw-winking syndrome (MGJWS) is a condition that can be mistaken for several other medical issues, all of which are related to abnormal movements, commonly referred to as “synkinetic abnormalities”. To accurately diagnose MGJWS, doctors have to consider and rule out these conditions:
- Inverted Marcus Gunn Phenomenon: In this case, drooping of the eye (ptosis) worsens when the mouth is opened. This is opposite to MGJWS where the drooping improves with mouth opening. The issue here involves an abnormal connection between the nerves controlling eye movements and the jaw.
- Marin-Amat syndrome: In this condition, there’s an irregular connection between the nerve that supplies the muscles used for chewing and the nerves that control the muscles of the forehead and cheeks. When a person with Marin-Amat syndrome opens their mouth, both eyes momentarily close due to a muscle response.
- Chronic progressive external ophthalmoplegia: This is a rare genetic disorder that affects eye movements and can cause drooping of the eyelids.
- Congenital fibrosis syndrome: This is a group of rare, genetic eye disorders that are present at birth and affect the muscle movements of the eyes.
- Myasthenia Gravis: This is a neuromuscular disorder that leads to weakness in the skeletal muscles, including those controlling eye movement.
Diagnosing MGJWS accurately requires careful investigation and consideration of these and other potential conditions.
What to expect with Marcus Gunn Jaw-Winking Syndrome
The outlook is typically positive for most cases. With careful observation and treatment, amblyopia, a condition where vision in one or both eyes does not develop properly during childhood resulting in decreased vision, can be successfully managed.
Possible Complications When Diagnosed with Marcus Gunn Jaw-Winking Syndrome
After undergoing surgery to correct droopy eyelids (ptosis surgery), there can be several complications. These include not enough correction or too much correction, inability to fully close the eye, formation of a small inflammatory mass due to the surgical suture, the surgical sling (used to suspend the eyelid) slipping or protruding, an uneven eyelid crease, and inflammation of the cornea due to the eye being unable to close properly. It’s also important to note that a condition called amblyopia (also referred to as ‘lazy eye’) is reported to be prevalent amongst 30% to 60% of people affected by Marcus Gunn Jaw-winking Syndrome (MGJWS).
Complications of Ptosis Surgery:
- Under-correction
- Overcorrection
- Inability to close the eye fully (lagophthalmos)
- Formation of a small mass due to surgical suture (suture granuloma)
- Slippage of the surgical sling
- Protrusion of the surgical sling
- Uneven eyelid crease
- Inflammation of the cornea due to eye being unable to close (exposure keratitis)
Additionally, half the people with Marcus Gunn Jaw-winking Syndrome experience lazy eye (amblyopia).
Preventing Marcus Gunn Jaw-Winking Syndrome
Marcus Gunn jaw-winking syndrome (MGJWS) is a condition that mostly causes only one symptom: jaw-winking. Most individuals won’t experience any other issues apart from this. Treatment is only needed if the condition is moderate to severe and causes vision problems or if the person wants to address it for appearance reasons. Also, it’s crucial for parents to understand that MGJWS can be related to other eye and general health issues. They should also be aware of what to expect post-surgery if their child has to undergo one for droopy eyelid (ptosis). Additionally, it’s important to stress the need for regular check-ups with an eye care professional.
