Sturge-Weber Syndrome (SWS) is an extremely rare epilepsy syndrome that the most recent figures indicate only occurs in around 1 in 20,000 births, but could be as few as 1 in 50,000.
With this syndrome, there is often a birthmark on one side of the face that’s often the first sign of SWS. This can informally be referred to as a ‘port wine’ stain. The syndrome itself is caused by a brain abnormality which affects the blood vessels on the surface of the brain, most commonly on the occipital lobe (the back part of the brain), and it’s this abnormality often leads to seizures.
This abnormality often forms during the first 3 – 4 months of pregnancy within the GNAQ gene. This happens sporadically, which means there is no genetic disposition to this syndrome (it doesn’t run in families).
Sturge-Weber Syndrome has been known by other names, including Encephalofacial Angiomatosis and Encephalotrigeminal Angiomatosis.
As previously mentioned, the birthmark is usually the first sign of this syndrome which will be prevalent during or after the birth. The birthmark is often flat and deep red and occurs due to the abnormalities in the small blood vessels under the skin. Medically, this is known as an ‘angioma’ and most commonly is first noticed on the forehead or on one side of the face, rarely both. Smaller birthmarks may be noticed on other areas of the body.
Two thirds of children with SWS will experience seizures, which may start from birth or within the first year of life. It’s rare for seizures to start any time after the age of 1. The seizures are usually focal in nature and cause a rhythmic jerk in one side of the body (face, limbs or both). However, seizures can become generalised and affect both sides of the body.
Atonic seizures can also be common in some children with SWS, also known as ‘drop attacks’. Myoclonic seizures and infantile spasms have also been recorded in children with SWS. These seizures can often be prolonged and in some cases result in status epilepticus, which requires emergency treatment.
As a result of frequent and prolonged seizures, many children with SWS will experience a weakness in one side of the body, which is called hemiparesis or hemiplegia. The extent of the weakness is often dictated by the frequency and severity of the seizures.
Disturbance of vision is a common symptom associated with SWS, and often affects peripheral vision on the weakened side. In addition, the child may experience difficulty with the drainage of the fluid in their eye, which can result in increased pressure (glaucoma) and can cause visual impairment if not treated. Any child who is diagnosed with SWS should be referred to a specialist in paediatric eye disorders.
Diagnosis of SWS is often fairly uncomplicated due to the telltale birthmark. However, this can be more difficult if the birthmark is pale or is hidden on the scalp and covered by hair. A computerized tomography (CT) scan will be used to confirm a diagnosis and show the typical abnormalities associated with SWS.
Controlling the frequency of the seizures is the key to managing Sturge-Weber Syndrome and gaining a favourable outcome for the child. This is most commonly done with the use of anti-seizure medications (ASDs). Almost any anti-seizure medication can be used to treat SWS, although carbamazepine, levetiracetam, lamotrigine, sodium valproate and topiramate are the most common choices.
In some cases, SWS can be resistant to medication. If this is the case then consideration may be given to brain surgery. With SWS, the surgery would likely consist of disconnecting the part of the brain that is linked to the abnormal blood vessels that are causing the seizures. This surgery is known as a hemispherectomy.
If glaucoma does develop, it will most likely be managed by daily eye drops and in some cases may require an operation.
The birthmark may be managed by camouflage or laser treatment for cosmetic purposes and will likely need to be checked regularly by a dermatologist and ophthalmologist.
Sturge-Weber Syndrome is what is known as a slowly progressive condition. As the abnormal blood vessels affect the supply of blood to the brain, this can deteriorate over time as the blood flow reduces with age. Over time this can cause injury to the brain and can result in an atrophy (shrinking) of the affected side of the brain.
Weakness in one side of the body can also deteriorate as the child gets older and seizures can become more frequent. This is why early control of seizures is very important with SWS to prevent many of the symptoms from becoming worse over time.
Intellectual difficulties can also be prevalent with SWS, the severity of which can depend on whether the seizures have been managed from an early age. Early control offers a much more optimistic outlook.
If the abnormality is present on both sides of the brain (which is rare) there is often an increased chance of weakness, intellectual difficulties and more severe / frequent seizures.
National Epilepsy Training can help
For more information on Sturge-Weber Syndrome, please call us on 01706 373075 or email firstname.lastname@example.org.