Sturge-Weber syndrome (SWS): Causes, symptoms, diagnosis and treatment

Sturge-Weber syndrome

Sturge-Weber syndrome (SWS) is a rare condition present from birth. It causes blood vessels in the head to become too large and form growths, called angiomas. These growths can lead to a facial birthmark called a port-wine stain, complications in brain development and vision problems.

Current estimates show that around one baby in every 20,000 to 50,000 is affected by SWS. It occurs randomly in newborns due to a gene mutation, which means anyone can be born with SWS. Because it is caused by a mutation, it is not passed from parent to child. It affects males and females at equal rates, and can affect people of any ethnic or racial group.

Newborns with a facial port-wine stain have a 6% to 15% risk of developing SWS. The risk of having SWS increases to 25% if the port-wine stain covers half the face and if the ophthalmic branch of the trigeminal nerve is involved. (The ophthalmic nerve is responsible for providing sensation to parts of the eyes, face and skull.) The risk further increases to 33% when both sides of the face are involved. 

There are three types of Sturge-Weber syndrome:

• Type I is the most common. It features the facial port-wine stain, abnormal blood vessels that form growths in the brain (called leptomeningeal angiomas) and possible eye conditions like glaucoma.

• Type II also features the facial port-wine stain and possible eye disorders, but the brain is rarely affected.

• Type III only affects the brain.

How is Sturge-Weber syndrome diagnosed?

Sturge-Weber Syndrome can be detected early on in infancy if a child has a port-wine stain on their eyelids or forehead and is taken to see an ophthalmologist.

Imaging tests, such as an MRI or CT scan, can detect SWS in the brain. However, due to the progressive nature of SWS, initial scans may not show anything and should be followed up around age 2 or 3.

Symptoms of Sturge-Weber syndrome

The symptoms of Sturge-Weber syndrome vary in severity and are highly individual to each patient, starting with the type of SWS a person has. The most characteristic symptom is the facial port-wine stain, though this birthmark is absent in Type III SWS. 

The port-wine stain usually affects at least one eyelid, the temples and/or one side of the forehead. In some cases, the stain affects half the face or even the whole face. A port-wine stain can vary in color from light pink to dark purple, and may grow darker with age. It may also thicken and can lead to blood blisters in some cases.

Other symptoms of Sturge-Weber syndrome include:

• Glaucoma

• Visual impairment secondary to eye complications

• Increased risk for migraines

• Seizures

• Developmental delays

• Cognitive impairment

• Intermittent or permanent muscle weakness on one side of the body

• Stroke, mini-strokes or stroke-like episodes

Some symptoms are present at birth while others appear as a baby grows and SWS progresses.

Seizures caused by SWS usually affect the side of the body opposite from the port-wine stain. So, if a person with SWS has a port-wine stain on the left side of their face, the seizures would occur on or affect the right side of their body. Sometimes, both sides of the body may be affected. The frequency and severity of SWS-related seizures vary among patients and may worsen with age.

These seizures can be tonic, atonic or myoclonic. 

• A tonic seizure causes a person’s muscles to suddenly become stiff.

• An atonic seizure causes the muscles to suddenly relax, which makes the body go limp.

• A myoclonic seizure causes a muscle jerk, and can happen in clusters. 

Developmental delays and cognitive impairment are more common in patients who have severe or uncontrolled seizures. The younger a patient is when these seizures start, the more likely they are to have lower cognitive function. 

These delays and impairments range from mild learning disabilities to severe cognitive deficits. In some children with frequent seizures and decreased cognitive function, behavioral problems and difficulty with social skills may be present.

How does Sturge-Weber syndrome affect the eyes?

In addition to glaucoma, SWS can also lead to some other eye-related conditions or symptoms, including:

• Angiomas (growths) near or on the eyes

• Enlarged eyeballs

• Poor vision due to shrinkage of the optic nerve

• Cloudy vision

• Retinal detachment

• Appearance of streaks in the retina (angioid streaks)

• Vision loss following damage to the visual cortex of the brain (cortical blindness)

People with Type III SWS generally don’t develop eye problems, but can have cortical blindness due to its origin in the brain. This usually manifests as deficits in the visual field.

SWS and glaucoma

Glaucoma is a serious eye condition associated with Sturge-Weber syndrome. Around 60% of SWS patients have glaucoma at birth, and around 40% develop it later in life. Glaucoma is more likely to occur when a port-wine stain involves an eyelid. Overall, 30% to 70% of people with SWS have glaucoma.

Glaucoma associated with SWS often only affects the eye on the same side of the face as the port-wine stain, but it can occasionally affect both eyes.

If a child is born with a facial port-wine stain, they should be tested annually for glaucoma. SWS-related glaucoma is a complex disorder, and should be managed by a glaucoma specialist.

SWS and choroidal hemangiomas

Choroidal hemangiomas — benign blood vessel tumors — are present in up to 40% of people with SWS, though some sources cite a prevalence of up to 70%. They are more likely to occur if a person’s port-wine stain affects their upper eyelid. 

There are two types of choroidal hemangiomas: Diffuse choroidal hemangiomas and circumscribed choroidal hemangiomas.

A diffuse choroidal hemangioma (DCH) is a non-cancerous, non-life-threatening tumor usually located in the back portion of one eye in people with SWS. If a port-wine stain covers both sides of a person’s face, DCH can occur in both eyes. It is typically present at birth and grows over time.

Complications that can result from DCH include:

• Refractive error 

• Amblyopia (lazy eye)

• Retinal detachment

• Glaucoma

DCH can be identified early by an eye doctor, and should be screened for twice a year if a baby is born with a facial port-wine stain.

A circumscribed choroidal hemangioma is typically a single, raised reddish lesion that is not associated with a systemic disease. It is very rare in Sturge-Weber syndrome.

Living with Sturge-Weber syndrome

Due to Sturge-Weber syndrome’s variety of symptoms, every person has different experiences with the condition. It is possible for someone to be born with a port-wine stain on their face and not have any of the neurological symptoms of SWS, or not have SWS at all. 

It is also possible, though less common, for someone with SWS to have neurological symptoms even if they were born without a port-wine stain. Regardless of the type of SWS someone has, there may be treatment options to address the complications and symptoms.

Treatment for Sturge-Weber syndrome

The primary goal of treatment for Sturge-Weber syndrome is to decrease the frequency of seizures. To lessen seizure activity, anticonvulsive medication is typically prescribed. Low-dose aspirin has also been shown as effective in some cases.

If medication fails to control a person’s seizures, surgery may be considered. However, surgery is not recommended for patients affected by SWS on both sides of the brain.

Since glaucoma is a common symptom, an annual eye exam is recommended even if glaucoma is not found during the initial evaluation. Treatments for glaucoma include topical medications like eye drops and possible surgery.

Though this change is primarily cosmetic, port-wine stains can be lightened through laser surgery.

Physical therapy is also an option for patients with muscle weakness, and educational therapy is common for those with impaired cognition or developmental delays.

Page published on Wednesday, August 3, 2022

Medically reviewed on Monday, July 18, 2022