What is Sturge-Weber Syndrome?
Sturge-Weber syndrome (SWS) is a certain type of disorder that comes with skin-related and nervous system symptoms. It often comes with a skin condition called ‘angiomas’ which show up as particular kinds of birthmarks known as ‘port-wine stains’ or ‘nevus flammeus’, usually on the area of the face serviced by the trigeminal nerve. The term ‘encephalotrigeminal angiomatosis’ is another name used for it. Of all the disorders having symptoms with both the nervous system and the skin, it’s the third most usual kind, coming after neurofibromatosis and tuberous sclerosis. The impact on the nervous system can lead to different types of seizures, which can cause sudden, uncontrolled bodily movements or make the body stiff or limp.
What Causes Sturge-Weber Syndrome?
Sturge-Weber syndrome is a rare condition that isn’t inherited but happens because of changes in a gene known as GNAQ, which is found on chromosome 9. This syndrome might cause facial and pial angiomas (clusters of blood vessels). One theory suggests that these angiomas exist because certain primitive blood vessels do not go away as they should during development.
Another possibility is that the brain’s system for draining blood through veins does not fully mature. So, the smaller blood vessels and capillaries (tiny, thin-walled blood vessels) might get bigger or dilate to pick up the slack. This syndrome, therefore, reflects some issues with the development and maintenance of the body’s blood vessels.
Risk Factors and Frequency for Sturge-Weber Syndrome
Sturge-Weber syndrome, often referred to as SWS, is a rare condition. Its exact frequency is unclear, but it’s estimated that about 1 in 20,000 to 50,000 newborns are affected. SWS doesn’t play favorites: it affects both boys and girls, and doesn’t appear to be more common in any particular race.
Signs and Symptoms of Sturge-Weber Syndrome
Sturge-Weber syndrome is a medical condition and seizures are usually the first signs of it. Babies who are affected often experience a type of seizure called infantile spasms during their first year of life. These can then develop into other types of seizures such as atonic, tonic, or myoclonic. As the condition progresses, these seizures become more difficult to control with medication . It’s also common for affected individuals to have increasing weakness on one side of the body (hemiparesis) which often accompanies the seizures.
Another common symptom of Sturge-Weber Syndrome is a particular kind of birthmark called a ‘port-wine stain’. This usually appears on the forehead or cheeks, typically on one side and is present from birth. Unlike infantile hemangioma, another type of birthmark, a port-wine stain does not change as the person ages.
The risk of brain involvement in a child with a facial port-wine stain is between 10% and 35%. If both the upper and lower eyelids are involved, the risk of developing glaucoma goes up to 50%. Note, however, that not all individuals with port-wine stains have Sturge-Weber syndrome, and some may experience symptoms related to the brain without any facial symptoms.
When the syndrome affects the eyes in infancy, it can cause symptoms like increased blood vessels in the white part of the eyes, larger than usual eyes, cross-eyes, and excessive tearing. Other symptoms include intellectual disability, as well as preferences for using one hand and looking one way. It’s also not uncommon for about 20% of patients with Sturge-Weber syndrome to have slow-growing tumors in the vascular layer of their eyes (choroidal hemangiomas), usually on the same side as the port-wine stain. These tumors typically don’t cause any symptoms, but can sometimes lead to changes in the overlying retina.
Testing for Sturge-Weber Syndrome
The diagnosis of Sturge-Weber syndrome, a rare condition that can affect the skin, eyes, and nervous system, is based on several factors. These include common symptoms, facial appearance, and results from a brain scan known as a magnetic resonance imaging (MRI).
Doctors will often conduct an eye examination to check for glaucoma, a condition that can damage your eye’s optic nerve. An ultrasound of your eye can also be used to check for a condition known as choroidal hemangioma, which is when blood vessels grow abnormally under the retina.
X-rays of the skull can sometimes show unusual patterns, often referred to as “tram-track sign.” A computerized tomography (commonly called a CT scan) can help doctors see these patterns more clearly and gets a better view of the brain. Although CT scans are very useful, they expose the body to a small amount of radiation. Because of this, they are not typically recommended for routine use in children.
That’s where MRI scans come in handy. They are generally the recommended method for imaging the brain as they do not expose the body to radiation. MRIs are especially helpful in examining the back part of the brain, where the majority of issues related to Sturge-Weber syndrome are found.
Depending on what stage the disease is in, MRI scans can show different things. In the early stage, they can often show abnormal blood flow in the brain and quickened maturation of the protective coating around nerves called myelin. If a patient has experienced a recent event that has cut off the blood flow to part of their brain, the MRI may also show this.
In later stages of the disease, MRIs usually show an area in the brain where cells are not working correctly, leading to a process known as gliosis. Once this stage has been reached, the protective coating previously discussed often begins to shrink and the superficial veins in the brain may not be as easily seen.
A particular type of MRI, known as susceptibility-weighted images (SWI), can show unusual patterns in the folds of brain tissue. If a child with Sturge-Weber syndrome has normal results on a brain MRI at one year old, it is unlikely that they will have issues related to the brain later in life.
Additionally, a type of scan called a Fluorodeoxyglucose-Positron Emission Tomography (FDG-PET) may also be used. This can help doctors understand how the brain is processing energy, which can be helpful for planning surgeries to treat unmanageable seizures. In the early stages of the syndrome, the affected brain area usually processes energy faster than usual, but this slows down in the later stages.
Treatment Options for Sturge-Weber Syndrome
Sturge-Weber syndrome doesn’t have a specific treatment. The main goal is to control the seizures that the condition can cause. To do this, doctors often prescribe medication meant to prevent seizures. There are times when this medication may not work completely and the person continues to have seizures. In these instances, doctors might consider surgery as an option. This could involve removing half of the brain (hemispherectomy) or just removing the part of the brain that’s causing the seizures (focal resection).
However, surgery isn’t a good option for everyone. For instance, if the syndrome affects both sides of the brain, the patient would not be a good candidate for surgery. There is some evidence that low-dose aspirin can help reduce the frequency of seizures and episodes that are similar to stroke.
This syndrome can also affect patient’s eyes, causing a condition called glaucoma. Doctors recommend that patients get their eyes checked every year, even if they didn’t find glaucoma in the earlier tests. If the patient does develop glaucoma, the main goal is to reduce the fluid inside the eye to decrease the pressure, which can potentially stop further vision loss. Eye drops are often the first treatment for glaucoma that presents later in life. If glaucoma develops early in life and comes with certain other conditions, surgery might be considered to help drain the fluid (goniotomy or trabeculotomy). More intense surgeries might be used for resistant cases.
Patients with Sturge-Weber syndrome often have a birthmark often called a ‘port-wine stain’. This can be treated with a special laser treatment which destroys the blood vessels causing the birthmark, without harming the rest of the skin.
What else can Sturge-Weber Syndrome be?
Sturge-Weber syndrome can be clearly distinguished from other conditions. This can be done based on a person’s medical history, physical checkup, and results from a brain MRI scan. These other conditions include:
- Blue rubber bleb nevus syndrome
- Klippel-Trenaunay-Weber syndrome
- PHACES (this stands for abnormalities in the back of the brain, hemangiomas which are blood vessel malformations, abnormalities in the arteries, heart issues, anomalies in the eyes, and anomalies in the chest)
- Wyburg-Mason syndrome
What to expect with Sturge-Weber Syndrome
The outlook for these patients can vary and is largely dependent on how serious the associated health issues are.
Possible Complications When Diagnosed with Sturge-Weber Syndrome
Possible Health Issues:
- Seizures
- Events resembling stroke
- Glaucoma (a condition that damages your eye’s optic nerve)
Preventing Sturge-Weber Syndrome
The patient and their parents need to understand that unfortunately, there isn’t a complete cure for this disease. What we can do to help is provide treatments that can ease the symptoms and manage the effects of the condition on the nervous system and vision. Essentially, this means we’re treating the symptoms and problems the disease causes, rather than the disease itself.
