Sturge-Weber Syndrome: Understanding Stroke Risks And Complications

Sturge-Weber syndrome (SWS) is a rare, non-inherited genetic condition that affects the development of blood vessels in the brain, skin, and eyes. It is characterised by a port-wine stain birthmark on the forehead and upper eyelid on one side of the face, caused by an overabundance of capillaries. SWS also affects the brain, resulting in abnormal blood vessels, loss of tissue, and deposits of calcium in the cerebral cortex. These abnormalities can lead to seizures, muscle weakness, developmental delays, and glaucoma. While SWS is not typically characterised by stroke, the condition may increase the risk of stroke-like episodes and venous infarction due to the underlying vascular abnormalities.

What is Sturge-Weber syndrome?

Sturge-Weber syndrome (SWS) is a rare, non-hereditary neurological disorder that presents at birth. It is characterised by a port-wine stain birthmark on the forehead and upper eyelid on one side of the face. The birthmark varies in colour from light pink to deep purple and is caused by an overabundance of capillaries (small blood vessels) around the trigeminal nerve just beneath the skin's surface.

SWS is also accompanied by abnormal blood vessels on the brain's surface and the loss of tissue (atrophy) with deposits of calcium (calcification) in the cerebral cortex of the brain on the same side as the birthmark. SWS rarely affects other body organs.

The specific symptoms and severity of SWS can vary dramatically from person to person. Some individuals may develop characteristic skin abnormalities but no neurological abnormalities, while others may develop neurological abnormalities without the characteristic skin issues. Symptoms include:

• Seizures that begin in infancy and may worsen with age
• Intermittent or permanent muscle weakness
• Developmental delays and cognitive impairment
• Glaucoma (increased pressure within the eye) at birth or later, which can cause the eyeball to enlarge and bulge out of its socket (buphthalmos)
• Headaches, including migraines, and visual field defects such as the loss of vision in half the visual field in one or both eyes (hemaniopsia)
• Risk of stroke, stroke-like episodes or mini-strokes (transient ischemic attacks)
• Behavioural problems such as attention deficit disorder, mood disorders, and poorer social skills

Treatment for SWS is directed toward the specific symptoms that are apparent in each individual. Laser treatment may be used to lighten or remove the birthmark, while anticonvulsant medications may be used to control seizures. Physical therapy may help with muscle weakness, and educational therapy may assist those with impaired cognition or developmental delays.

What are the symptoms?

Sturge-Weber syndrome (SWS) is a rare, non-inherited, genetic condition that affects the development of blood vessels in a child's brain, skin, and eyes. It is characterised by a port-wine stain birthmark on the forehead and upper eyelid on one side of the face, caused by an overabundance of capillaries around the trigeminal nerve. The birthmark varies in colour from light pink to deep purple and can thicken and darken over time.

The syndrome is also accompanied by abnormal blood vessels on the brain's surface, known as leptomeningeal angiomas, which can affect blood flow to parts of the brain and lead to seizures and one-sided muscle weakness (hemiparesis). Seizures usually occur within the first year of life, often before the child's second birthday, and can worsen with age. They typically affect the side of the body opposite the birthmark but can sometimes affect both sides.

Other symptoms of SWS include:

• Glaucoma, which is an increase in pressure in the eye from fluid buildup, leading to possible vision loss. Glaucoma usually affects the eye on the same side as the port-wine birthmark.
• Developmental delays and intellectual disabilities, which can lead to lower cognitive function and quality of life.
• Headaches or migraines.
• Stroke-like episodes, which can cause temporary weakness or paralysis on one side of the body.
• Behavioural problems such as attention deficit disorder, mood disorders, and poor social skills, particularly in children with lower cognitive function and a greater frequency of seizures.
• Endocrine disorders, such as central hypothyroidism and an increased risk of growth hormone deficiency.

The symptoms of SWS vary from person to person, and not all symptoms affect each child. The specific symptoms and severity of the disorder can vary dramatically from one person to another.

What causes it?

Sturge-Weber syndrome (SWS) is a rare vascular disorder characterised by a port-wine birthmark on the face, abnormal blood vessels in the brain, and eye abnormalities such as glaucoma. The birthmark is caused by an overabundance of capillaries around the trigeminal nerve just beneath the surface of the face. The syndrome is also accompanied by abnormal blood vessels on the brain's surface, as well as loss of tissue (atrophy) and deposits of calcium (calcification) in the cerebral cortex of the brain on the same side as the birthmark.

SWS is caused by a somatic mutation, most commonly in the GNAQ gene, which occurs randomly and for no known reason. This mutation results in alterations in the regulation of the structure and function of blood vessels, vascular innervation, and expression of extracellular matrix and vasoactive molecules. The GNAQ gene creates G protein alpha subunit q (Gaq) that plays an important role in cell function, including the regulation of blood vessels. 90% of SWS patients have R183Q mutations in GNAQ which leads to over-activation of downstream pathways to Gaq. This hyperactivation, in turn, leads to congenital vascular abnormalities.

The abnormal blood vessels that make up the port-wine birthmark vary in size, diameter, distribution, and depth from one individual to another and even within the same person in different affected areas. This means that each person's birthmark is unique and can be quite dissimilar from another person's.

The abnormal blood vessels on the brain's surface, or leptomeningeal angiomas, may affect blood flow to parts of the brain, leading to seizures and one-sided muscle weakness (hemiparesis). These angiomas can also increase the risk of calcification (calcium deposits) and loss of brain tissue (atrophy).

SWS can be classified into three main subtypes based on the presence or absence of facial and leptomeningeal angiomas:

• Type 1: The classic syndrome (most common) with both facial and leptomeningeal angiomas, with or without glaucoma. Seizures usually occur within the first year of life, and mental and physical development is impaired to varying degrees.
• Type 2: Facial angioma without evidence of intracranial disease, with or without glaucoma.
• Type 3: Isolated leptomeningeal angioma with no facial involvement, usually without glaucoma.

The specific symptoms and severity of SWS can vary dramatically from one person to another. While SWS is not typically characterised by stroke, the venous malformation may predispose individuals to venous (hemorrhagic) infarction (due to venous or sinus thrombosis). SWS-related stroke-like episodes may be triggered by seizures or migraines, but they can also develop without any evidence of epilepsy.

What are the complications?

Sturge-Weber syndrome (SWS) is a rare vascular disorder that can lead to a variety of complications. The condition is characterised by a port-wine stain birthmark on the forehead and upper eyelid on one side of the face, caused by abnormal blood vessels in the brain and eye abnormalities such as glaucoma. The abnormal blood vessels can vary in size, distribution and depth, even within the same person. The specific symptoms and severity of the disorder can vary dramatically from person to person.

Seizures

Seizures are a common symptom of SWS, often beginning in infancy or childhood and usually affecting the opposite side of the body to the port-wine birthmark. Seizures can vary in frequency and intensity and sometimes worsen with age. They can be treated with anti-seizure medications or surgery.

Muscle Weakness

Individuals with SWS may experience muscle weakness or paralysis on one side of the body, usually on the side opposite the brain involvement and the port-wine birthmark. This can be treated with physical therapy.

Developmental Delays and Intellectual Disability

SWS can cause developmental delays and intellectual disabilities ranging from mild learning difficulties to severe cognitive deficits. Special education courses can help manage these symptoms.

Glaucoma

Glaucoma is a common complication of SWS, marked by increased pressure within the eye, which can cause the eyeball to enlarge and bulge out of its socket. Glaucoma can be treated with medicated eye drops or surgery.

Headaches and Visual Field Defects

Headaches, including migraines, and visual field defects such as the loss of vision in half of the visual field in one or both eyes, can occur in individuals with SWS.

Stroke-like Episodes

SWS is associated with a risk of stroke, stroke-like episodes or mini-strokes (transient ischemic attacks). These episodes can cause temporary weakness or paralysis of half of the body and visual field defects. The exact cause of these episodes is unknown, but they may be triggered by seizures or migraines.

Eye Abnormalities

Other eye abnormalities can occur, such as the development of angiomas in the membranes lining the eyelids, the layer of blood vessels and connective tissue between the white of the eye and the retina, and the clear membrane covering the cornea. Eye colour may vary between the two eyes. Additional ocular symptoms can include an abnormal accumulation of fluid inside the eyeball, degeneration of the cranial nerve, clouding or displacement of the lenses, retinal detachment, streaks in the retina, and loss of vision due to an organic lesion in the visual cortex.

Endocrine Disorders

Endocrine disorders such as central hypothyroidism and an increased risk of growth hormone deficiency have also been reported in individuals with SWS.

Other Symptoms

Other possible complications of SWS include an abnormally large head, overgrowth of soft tissues underlying the port-wine birthmark, and lymphatic malformations, which are non-malignant masses consisting of fluid-filled channels or spaces.

The complications of SWS can vary widely between individuals, and not all symptoms will affect every patient. Treatment options are available to help manage the symptoms and improve quality of life.

How is it treated?

Sturge-Weber syndrome (SWS) is a rare disorder that affects the brain, skin, and eyes. While there is no cure for the condition, there are treatments available to help manage symptoms and improve a patient's quality of life. Treatment is tailored to each individual, depending on their unique symptoms and needs. Here is a detailed overview of how Sturge-Weber syndrome is treated:

Laser Therapy for Birthmarks

The port-wine birthmark, a common symptom of SWS, can be treated with laser therapy. Laser treatment can lighten or remove the birthmark by destroying the abnormal blood vessels without damaging the surrounding skin. This treatment is available for children as young as one month old and may require multiple sessions as the birthmark tends to return or darken.

Anticonvulsant Medications for Seizures

Seizures, another common symptom of SWS, can be controlled with anti-seizure medications such as levetiracetam, low-dose aspirin, and oxcarbazepine. In severe cases of seizures that are resistant to medication, surgery may be considered. Surgical options include hemispherectomy (removing half of the brain affected by seizures), focal cortical resection (removing a specific area of the brain causing seizures), and vagal nerve stimulation (implanting a device to transmit mild electrical impulses to the brain to prevent seizures).

Glaucoma Treatment

Glaucoma, or increased pressure within the eye, can be treated with medicated eye drops or oral medications to decrease fluid production in the eye. In more severe cases, surgery may be necessary to improve fluid flow and prevent vision loss. Regular ophthalmological exams are recommended to monitor and treat glaucoma and increased intraocular pressure.

Physical Therapy for Muscle Weakness

Physical therapy can help patients with muscle weakness or paralysis on one side of the body (hemiparesis) to improve muscle strength and function.

Educational Therapy for Developmental Delays

Educational therapy can assist patients with developmental delays or cognitive impairments. Special education courses can help address intellectual disabilities and improve quality of life.

Low-Dose Aspirin for Adults

Healthcare providers may recommend low-dose aspirin for adults with SWS to reduce the risk of stroke and stroke-like symptoms. However, children should not take aspirin unless specifically recommended by their healthcare provider.

Migraine Treatment

Preventative treatment for migraines, which are common in patients with SWS, may include medications such as propranolol or verapamil. Some anti-seizure medications, such as gabapentin, topiramate, and valproic acid, may also help treat migraines.

Endocrine Abnormalities Treatment

Endocrine abnormalities, such as central hypothyroidism and growth hormone deficiency, require screening and treatment. For example, central hypothyroidism can be treated with synthroid to relieve symptoms.

Frequently asked questions