Sturge-Weber syndrome

Definition

Sturge-Weber syndrome (SWS) is a rare, congenital (present at birth), noninherited disorder characterized by the vascular malformation (birthmark) called a port wine stain, usually seen on an infant's face. Sturge-Weber also is characterized by neurological abnormalities including seizures, weakness on one side of the body, developmental delay , and glaucoma (increased pressure within the eye). Other terms for SWS are: encephalotrigeminal angiomatosis, encephalofacial angiomatosis, or Sturge-Weber-Dimitri syndrome.

Sturge-Weber syndrome is named for the British physicians William A. Sturge (1850–1919), who first described the condition, and Frederick Parkes Weber (1863–1962) who demonstrated its intracranial calcifications.

Description

SWS is a rare congenital disorder whose most apparent indication is a port wine stain on the face that is associated with neurological abnormalities. The port wine stain is a benign tumor just under the surface of the skin, made up of overabundant blood vessels (angiomas). Port wine stain may affect either or both sides of the face and can vary in size. Other neurological abnormalities may be present, including angioma on the brain's surface.

Demographics

The incidence of SWS is estimated at one per 50,000 live births in the United States. No regional or gender differences have been noted. An estimated 13 percent of individuals with SWS will not have the port wine stain. In addition, some children with port wine stain may not have Sturge-Weber syndrome.

Causes and symptoms

The exact cause and incidence of Sturge-Weber syndrome was as of 2004 not understood. It is not thought to be genetic.

Frequency of symptoms

A child born with SWS has a higher likelihood of the following clinical signs of the disorder:

port wine stain: 8–15 percent
bilateral (both sides) brain involvement: 15 percent
seizures: 72–93 percent
hemipareis (weakness on one side of body): 25–56 percent
hemianopsia (loss of half of the field of vision): 44 percent
headaches: 44–62 percent
developmental delay/mental retardation: 50–75 percent
glaucoma (increased pressure within the eye): 30–71 percent
choroidal hemangioma (nonmalignant blood vessel tumors in the eye): 40 percent

The following manifestations of SWS may be present:

Port wine stain: The port wine stain is caused by excess capillaries (tiny blood vessels) just below the skin's surface. It may vary in color, shape, and location on the face. Sometimes the port wine stain covers other parts of the body as well as the face.
Seizures: Angiomas on the surface of the brain cause seizures in nearly all children with SWS. As the child grows, the affected part of the brain can atrophy (waste away). Deposits of calcium also may occur. This can cause seizures to become more frequent and to last longer.
Hemipareis (weakness on one side of body): In SWS, this results from frequent seizures.
Hemianopsia (loss of half of the field of vision): Angiomas can affect the optic nerve, causing blindness in half of the eye.
Headaches: About one-third of children aged ten years and younger with SWS suffer from migraines.
Developmental delay/mental retardation: Seizures are responsible for learning difficulties in two out of three children with SWS.
Glaucoma (increased pressure within the eye): Glaucoma is present in 70 percent of children with SWS whose upper eyelids have port wine stain. Fluid produced within the eye (aqueous humor) cannot exit normally. This leads to increased pressure within the eye and eventual damage to the optic nerve.
Choroidal hemangioma (nonmalignant blood vessel tumors in the eye): Noncancerous tumors can grow within the eye on the choroid blood vessel, the vessel that nourishes the eye. If the tumor is in the central area of vision, visual function can be affected.

When to call the doctor

An infant born with a port wine stain will be immediately evaluated by healthcare staff. In some cases, infants with SWS will not have a port wine stain present at birth. In these cases, suspicion of SWS may not arise until a child has a seizure or other neurological problem.

Diagnosis

Clinical diagnosis of SWS begins with the observation of port wine stain in an infant. The port wine stain may not be obvious in children of color. Not all children with port wine stain will have SWS, however; and some children with SWS will not have port wine stain. In the absence of port wine stain, other neurological abnormalities will help determine the diagnosis. Seizures may be the first symptoms of SWS in a child, usually by the first year. The seizures are usually frequent and may be prolonged. If glaucoma is involved, there may be no symptoms in older children. Infants may avoid bright light as a result of enlarged corneas.

If neurological involvement is suspected, the following tests may be used to help make a diagnosis:

X ray of the skull to show calcifications (calcium deposits)
CT scan of the skull to show calcifications, abnormal veins, and brain atrophy
MRI to show angiomas (benign tumors made up of blood vessels)
single-photon emission computed tomography to measure blood flow in the brain
EEG to evaluate seizures

Treatment

Treatment for SWS depends on the disorder involved.

Port wine stain: Laser treatment is used to lighten or remove port wine stain. Pulsed-dye laser therapy successfully treats port wine stain without significant scarring. Treatment should start as soon as possible. Multiple treatments will be necessary.
Seizures: Drug therapy may be used to control seizures. However, the seizures often are resistant to treatment. In some cases, early surgical removal of the part of the brain with the abnormal blood vessels may be considered.
Vision problems: Drug therapy may be used to treat glaucoma. Photodynamic therapy also is used to treat choroidal hemangiomas that affect the eye.
Headaches: Medications may be taken to treat migraines. Children age two and under should not take aspirin due to the risk of Reye syndrome.
Developmental delay and learning problems: A wide range of treatment options is available to children with developmental delay and learning problems associated with SWS.
Hemipareis (weakness on one side of body): Hemipareis can be treated with physical and occupational therapy.

Prognosis

SWS is not a fatal disease. The prognosis for SWS depends on the specific neurological abnormalities present. Some abnormalities associated with SWS may worsen with age. Successful treatment of seizures improves the outlook for children with SWS.

Prevention

There was as of 2004 no known way to prevent SWS. Nothing a parent has done or did not do causes the disorder.

Parental concerns

The seizures that are often present with SWS can place children in potentially dangerous situations.

KEY TERMS

Angioma —A tumor (such as a hemangioma or lymphangioma) that mainly consists of blood vessels or lymphatic vessels.

Anomaly —Something that is different from what is normal or expected. Also an unusual or irregular structure.

Capillaries —The tiniest blood vessels with the smallest diameter. These vessels receive blood from the arterioles and deliver blood to the venules. In the lungs, capillaries are located next to the alveoli so that they can pick up oxygen from inhaled air.

Choroidal hemangioma —A nonmalignant blood vessel tumor in the eye.

Hemianopsia —Loss of half of the field of vision.

Hemiparesis —Weakness on one side of the body.

See also Seizure disorder .

Resources

PERIODICALS

Baselga, E. "Sturge-Weber syndrome." Seminars in Cutaneous Medicine and Surgery 23, no. 2 (June 2004): 87–98.

Lam, Samuel, et al. "Practical Considerations in the Treatment of Capillary Vascular Malformations, or Port Wine Stains." Facial Plastic Surgery (2004): 71–6.

Thomas-Sohl, K. A., et al. "Sturge-Weber syndrome: a review." Pediatric Neurology 30 (May 2004): 303–10.

ORGANIZATIONS

American Academy of Dermatology. 930 E. Woodfield Rd., Schaumburg, IL 60168. Web site: http://www.aad.org/

Children's Hemiplegia and Stroke Association. Suite 305, PMB 149 4101 W. Green Oaks. Arlington, TX 76016. Web site: http://www.hemikids.org/hemiplegia.htm.

FACES: The National Craniofacial Association. PO Box 11082, Chattanooga, TN 37401. Web site: http://www.facescranio.org/.

National Association for Rare Disorders. 55 Kenosia Avenue, PO Box 1968, Danbury, CT 06813–1968. Web site: http://www.rarediseases.org/info/contact.html.

Sturge-Weber Foundation. PO Box 418, Mount Freedom, NJ 07970. Web site: http://www.sturge-weber.com/.

WEB SITES

"NINDS Sturge-Weber Syndrome Information Page." National Institute of Neurological Disorders and Stroke , 2001. Available online at http://www.ninds.nih.gov/health_and_medical/disorders/sturge_doc.htm (accessed November 30, 2004).

Sturge-Weber Foundation. Available online at http://www.sturgeweber.com (accessed November 30, 2004).

"Sturge-Weber Syndrome." eMedicine , 2001. Available online at http://www.emedicine.com/neuro/topic356.htm#section~workup (accessed November 30, 2004).

"Sturge-Weber Syndrome." Epilepsy Action. Available online at http://www.epilepsy.org.uk/info/sturge.html (accessed November 30, 2004).

Christine Kuehn Kelly