STURGE-WEBER SYNDROME

Sturge-Weber is a condition which consists of a birth mark always involving the forehead and a similar blood vessel abnormality on the brain surface (often called an angioma). Sometimes the birth mark may be on one side only, sometimes it is on both sides. Occasionally it may also be on the trunk or limbs, again on one or both sides. Some people have the birth mark and nothing else. Occasionally it is possible to have no birth mark at all but still have the brain angioma. The angioma also can sometimes be on both sides, although usually it is one side only. The size of the birth mark is not necessary a guide to the size of the brain angioma. If the birth mark is only one side, often the brain angioma is on the same side but there are many exceptions to this.

The problems

The birth mark may appear unsightly and it is therefore of cosmetic significance but does not otherwise do harm. This unfortunately is not true with the angioma on the brain surface. By some process which probably involves depriving the underlying brain of some of its blood supply, the underlying brain shrinks, and specks of calcium appear in it. These specks of calcium may be shown up on a CT scan or even on an ordinary x-ray. This process probably also causes the brain angioma to grow over the surface of the brain usually from the back towards the front. This however takes many years.

This brain involvement causes three main problems. Firstly, about half the people with Sturge-Weber have significant learning problems. Significant means either needing special help in ordinary schools or going to a school for slow learners. Secondly, epilepsy occurs in up to nine out of ten people with Sturge-Weber. It usually starts in the first year of life. The fits usually involve stiffness or jerking of the body on the side opposite to the brain angioma, Other types of fits may occur (see the special leaflet on Epilepsy in Sturge-Weber). Although it is not thought that the fits cause learning difficulties, there is an indirect association, so that if you are one of the fortunate minority who do not have fits, you do not have learning problems either. On the other hand, three-quarters of those with fits have learning problems as well.

The last problem is weakness or stiffness down one side of the body affecting the arm, leg and side of face. This is called a hemiplegia and looks quite like somebody who has had a stroke. This happens in about one-third of people with Sturge-Weber. Again, it occurs on the side opposite to the brain angioma. Similarly to the fits and learning problems, it is not thought to be caused by the fits. The association is indirect so that if the hemiplegia happens, it usually comes on after the fits start, and may get more obvious if the fits continue. The degree of the hemiplegia varies enormously. Often it is fairly mild, causing clumsiness in the hand and some stiffness in the leg in walking. It is rarely bad enough to stop someone walking altogether. Occasionally it can occur briefly and then go away.

Other complications

If the birth mark is on the eyelid, particularly the upper eyelid, this may cause increased pressure in the eye. This is called glaucoma. About one third of people with Sturge-Weber are at risk from this complication. The increased pressure can cause enlargement of the eye and if unchecked, blindness in that eye. It is very important, therefore, if the eyelids are involved that the eye pressure is checked regularly.

This is something that is easy for an eye specialist to do. Occasionally the eye is already affected when the child is born. The eye specialist should then see the child early.

Sometimes only half the field of vision is present in each eye. The technical name for this is hemianopia. This is actually more common than is often thought because people who have it do not realise it (for example, each of our eyes has a blind spot although we are not actually aware of it). Children with this compensate automatically, by moving their heads more to see the full range of view. People with hemianopia should not drive.

Causes

At a very early stage in the development of the embryo, the skin of the forehead overlies the structure which later becomes the back of the brain. The blood vessels in the embryo are normally modified as the baby develops during pregnancy. It is thought that in Sturge-Weber this modification to the early blood vessels in this area does not take place. It is not known why not.

It is probably not hereditary. If a first child has it, the chances of further children having it are less than one in a hundred. There are cases on record of each in a pair of identical twins having it, and also of only one in a pair having it. There is also one record of both the father and the son having it but this is so rare that it is probably a coincidence. It seems that the hitch in blood vessel development is an accident of nature. Nothing that happens or does not happen in pregnancy seems to cause it.

Neither the birth mark nor the brain angioma are painful and neither do they bleed.

Treatment

Since we do not know the basic cause we cannot prevent it. Fits need controlling. Once the first fit has occurred, others will almost surely follow, so treatment with anti-convulsants should not be delayed. With development of newer anti-convulsants fit control is improving. However, there are a few people in whom anti-convulsants seem less effective. In these people neurosurgery, even in infants, may have real advantages and should be considered seriously.

Learning problems need careful evaluation by an educational psychologist. Parents will need to discuss their child's educational needs with the person making the assessment, and together with them decide how best to meet those needs.

Physiotherapists and occupational therapists can help people cope with hemiplegia. Traditionally, physiotherapists help with walking and occupational therapists with hand function. However, there is much overlap, so they may need to collaborate and you need to check if necessary with each of them that all difficulties are being addressed. The problem with eye pressure has already been mentioned.

If the pressure in the eye is increasing, it can often be controlled by eye drops. If not surgery may be necessary.

Laser treatment for removal of the port wine stain has been steadily improving. At the moment it appears that the pulsed dye laser is overtaking the Argon laser. Children are usually less bothered by the birth mark than are their parents, and in this situation there is something to be said for waiting for further improvements to occur and long-term results to become available. This work is only done by a very few centres in the NHS. A skin specialist (dermatologist) should be able to refer you to the nearest centre for up to date information and advice.