Epilepsies

Sturge-Weber syndrome

A neurocutaneous disorder — facial port-wine birthmark, leptomeningeal angiomatosis, often epilepsy and glaucoma — caused by a somatic GNAQ mutation, with low-dose aspirin and targeted treatments now standard.

Sturge-Weber syndrome (SWS) is a sporadic neurocutaneous disorder caused by a somatic mutation in the GNAQ gene (rarely GNA11) that occurs in a small population of cells in early embryonic life. The mosaic distribution explains the typical triad: a facial port-wine birthmark in the V1 (forehead) territory, a leptomeningeal angiomatosis underneath the affected side of the brain (almost always ipsilateral), and ocular involvement with glaucoma. Most children develop drug-resistant focal seizures in the first two years of life, often with subsequent hemiparesis and learning difficulties — but a meaningful minority have a milder course. The understanding of why the brain manifestations progress (low cerebral perfusion underneath the abnormal vessels, with secondary venous stasis, mineralisation and cortical injury) underpins the modern use of low-dose aspirin as a vascular preventive therapy. Hemispherotomy remains the most effective treatment for severely drug-resistant, hemispheric SWS.

At a glance

Cause: Somatic post-zygotic GNAQ p.R183Q mutation (rarely GNA11)
Triad: Facial port-wine birthmark (V1) · leptomeningeal angiomatosis · glaucoma
Common features: Drug-resistant focal seizures in infancy, contralateral hemiparesis, learning difficulties, hemianopia
Risk by facial pattern: V1-only port-wine carries 35–50% brain involvement risk; V1 + V2/V3 (or bilateral) significantly higher
Prevention: Low-dose aspirin from infancy reduces seizure burden and stroke-like events in most centres

What it is

Sturge-Weber syndrome arises from a somatic activating mutation in GNAQ (the alpha subunit of a G-protein) that occurs in a clone of cells early in embryogenesis. Cells carrying the mutation form abnormal capillary-venous vessels in the skin (the port-wine birthmark), in the leptomeninges of the brain (leptomeningeal angiomatosis) and in the eye (choroidal angioma, with secondary glaucoma).

Because the mutation occurs in only some cells, the distribution is mosaic. This explains both the segmental pattern of skin and brain involvement (almost always unilateral) and the fact that the same GNAQ mutation, when limited to skin only, causes isolated port-wine staining without brain involvement.

How it presents

Most children are recognised at birth by the facial port-wine birthmark. The risk of brain (and eye) involvement is determined more by the distribution of the birthmark than its size — V1-only birthmarks (forehead and upper eyelid) carry a 35–50% risk; bilateral, or V1 + V2/V3 patterns, carry a higher risk and warrant a brain MRI in infancy.

Seizures typically begin between 6 and 24 months, often triggered by a febrile illness, and are usually drug-resistant focal motor seizures (with or without secondary generalisation). Status epilepticus, with stroke-like episodes during prolonged events, is a recognised complication. Cognitive and motor development can be normal until the first seizure cluster, then plateau or regress. Glaucoma can present at birth or develop later; lifelong ophthalmology follow-up is essential.

Diagnosis

Brain MRI with gadolinium contrast is the cornerstone — showing leptomeningeal enhancement over the affected hemisphere, often with associated cortical calcification (the 'tram-track' pattern on CT), enlarged choroid plexus, deep medullary vein collaterals, and progressive cortical atrophy in time. Susceptibility-weighted imaging (SWI) shows the abnormal venous drainage particularly well.

Genetic confirmation can be made by sequencing the affected skin or, less commonly, brain tissue — though this is rarely needed clinically.

Treatment

Modern SWS care has three pillars — vascular prevention, seizure control and reconstructive ophthalmology / dermatology:

Low-dose aspirin (3–5 mg/kg/day) from infancy in children with confirmed brain involvement — observational evidence and a 2022 randomised pilot suggest fewer stroke-like events and fewer seizures, with minimal bleeding risk in this dose range. Started at diagnosis, continued lifelong
Antiseizure medicines — phenytoin and carbamazepine have traditionally been used because most seizures are focal-onset. Levetiracetam and oxcarbazepine are widely used; many centres also use clobazam as add-on. Vigabatrin and valproate are options
Hemispherotomy / hemispherectomy — the most effective treatment for severely drug-resistant SWS limited to one hemisphere. Performed in selected centres in the second year of life or later, with seizure freedom in 75–85%, often allowing cognitive recovery and reduced developmental loss compared with prolonged seizures
Sirolimus and other mTOR inhibitors — under investigation given the downstream signalling effects of the GNAQ mutation; some open-label data, no licensed indication yet
Ophthalmology — early and lifelong glaucoma management, with topical medications, laser or surgery as needed
Dermatology — pulsed-dye laser treatment of the facial port-wine birthmark, starting in infancy in many centres, with multiple treatments throughout childhood

Prognosis

Outcomes vary widely. About a quarter of children with brain involvement have a relatively mild course with infrequent seizures and normal cognition; the remainder have varying degrees of motor, visual-field and cognitive impact related to the seizure burden in early childhood and the underlying vascular injury. Early diagnosis, low-dose aspirin and aggressive seizure management — including timely surgery when indicated — improve long-term outcomes meaningfully.

How an educational review can help

Families navigating SWS often face difficult decisions about MRI timing, when to start aspirin, the role of hemispherotomy and how aggressive to be with epilepsy treatment. An educational review can pull together the most recent literature — particularly the 2022 aspirin trial data and the current surgical outcomes — and help you prepare focused questions for your treating team.

It is an educational second opinion — not a diagnosis, treatment or prescription — and it does not replace the care of your child's own clinicians.

Selected sources

Comi AM et al. Sturge-Weber syndrome: review of the literature and updated treatment recommendations. Neuropediatrics 2020.
Shirley MD et al. Sturge-Weber syndrome and port-wine stains caused by somatic mutation in GNAQ. New England Journal of Medicine 2013; 368(21): 1971–9.
Lance EI et al. Aspirin use in Sturge-Weber syndrome: side effects and clinical outcomes. J Child Neurol 2013; pilot RCT 2022.
Sturge-Weber Foundation / Brain Vascular Malformation Consortium consensus statements 2022–2024.

Last reviewed: 2026-05-27

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