Sturge-Weber syndrome

Medical quality assurance by Dr. Albrecht Nonnenmacher, MD at August 18, 2016
StartDiseasesSturge-Weber syndrome

Sturge-Weber syndrome, often abbreviated SWS, is a rare congenital disorder. The condition is characterized by a distinctive port-wine birthmark affecting the face, abnormalities involving the eyes and brain, and possible developmental delays. It is also common for individuals with SWS to experience convulsions or seizures. The official medical term for Sturge-Weber syndrome is encephalotrigeminal angiomatosis.

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Definition & Facts

According to statistics from the National Organization for Rare Disorders, SWS only occurs once per every 20,000 to 50,000 births. A child with Sturge-Weber syndrome may not be born with a port-wine stain; however, a birthmark will typically develop soon after birth. Only about six percent of babies born with port-wine stains have SWS.

A port-wine stain is caused by an abundance of capillaries near the skin’s surface that dilate and make the skin appear red or discolored. To be diagnosed with SWS, a child must also have abnormal blood vessels in the brain affecting the same side of the body as the port-wine stain. Sturge-Weber appears to affect all races and genders with equal frequency. 

Symptoms & Complaints

In some cases, the abnormal blood vessels in the brain are asymptomatic, in others they can cause:

There is also a strong link between Sturge-Weber syndrome and eye problems. According to statistics from the American Association for Pediatric Ophthalmology and Strabismus, approximately one-half of children born with SWS will develop glaucoma during their infancy or childhood. Glaucoma causes an increase in pressure inside the eye, which can lead to eye pain, sensitivity to light, and visual impairment.

Approximately 80 percent of children with SWS also experience seizures. 75 percent of these children are able to either fully or partially control their seizures with the help of medication. Medication is ineffective in controlling seizures in approximately 25 percent of cases.

Increased vascularity involving the tissues and bones of the face and jaw can also lead to periodontal problems, including the premature eruption of permanent teeth and tooth loss. Patients with SWS are 21 times more likely to experience growth hormone deficiency and other endocrine-related issues; however, further studies are needed to fully understand the connection.

Causes

Sturge-Weber syndrome is the result of a random genetic mutation affecting the GNAQ gene; therefore, it is not inherited. The abnormal blood vessel formation associated with Sturge-Weber syndrome occurs in utero. Around the sixth week of pregnancy, a network of nerves forms around what will eventually become the baby’s head. These nerves typically disappear around the ninth week of gestation. In cases of SWS, these nerves remain. This deprives the brain of essential blood and oxygen, which can impact brain tissue development. Dr. E. Steve Roach was the first to classify SWS according to a spectrum based on the severity of symptoms.

  • Type 1 is the most common form of SWS. It involves both facial and brain vascular malformations. It is common for patients with Type 1 SWS to experience both glaucoma and seizures. The severity of physical and mental impairment varies depending on the extent of the vascular malformations in the brain.
  • Patients with Type 2 SWS have the typical facial port-wine stain and an increased risk of developing glaucoma, but they do not normally exhibit evidence of intracranial disease.
  • Type 3 is the most difficult form of SWS to diagnose. This type of SWS is characterized by abnormal blood vessels in the brain without the usual facial involvement. This form of SWS is usually only diagnosed after a contrast magnetic resonance imaging (MRI) reveals the vascular malformations in the brain. 

Diagnosis & Tests

The diagnosis of Sturge-Weber syndrome typically depends on identifying facial and brain vascular malformations. Any child born with a port-wine stain birthmark who also experiences neurological symptoms should undergo a complete neurological examination.

Even in the absence of neurological symptoms, children with an extensive port-wine birthmark that affects the eyelids or both sides of the face should also undergo a neurological screening. An MRI with contrast enhancement is the gold standard for the screening and monitoring of Sturge-Weber syndrome.

A computed tomography (CT) scan is also useful in providing information about the structures of the brain and identifying brain calcifications. It is important to remember that early scans may appear negative and are not necessarily enough to exclude a diagnosis of SWS. It may be necessary for some patients to undergo follow-up testing, especially if they start to develop neurological symptoms. 

Treatment & Therapy

Treatment for Sturge-Weber syndrome depends on the particular collection of symptoms that the patient is experiencing. The majority of SWS patients require medications to control seizure activity and prevent further cognitive and neurological decline. Surgery may be necessary in cases where medications are ineffective in preventing seizures. This may range from limited resections to a hemispherectomy when there is extensive brain involvement.

Laser surgery may help reduce the size and appearance of the port-wine birthmark. Early treatment provides the best results since the area typically thickens and darkens with age. Medications are the first line of treatment in reducing intraocular pressure and preventing glaucoma.

The increased vascularity of the tissues of the face and jaw can lead to increased bleeding during dental procedures. While patients with SWS should still get routine dental care, they should seek out a dentist who can modify treatment methods to reduce the risk of localized trauma. A specialist should perform oral surgeries and extractions because of the unique challenges involved.

Physical therapy and educational therapy are often beneficial in helping children with Sturge-Weber overcome physical and mental developmental delays. Psychotherapy and/or counseling may be beneficial in helping the child cope with the behavioral and emotional aspects of living with the condition. 

Prevention & Prophylaxis

Since Sturge-Weber syndrome is the result of a genetic mutation, there is no way to prevent the condition. SWS is rarely life-threatening. The individual’s quality of life and level of functioning largely depend on the extent of the vascular abnormalities in the brain and how well the neurological symptoms, such as seizures, are prevented or controlled.