What is this, in one plain sentence?
Sturge-Weber Syndrome is a non-hereditary neurocutaneous disorder caused by a somatic GNAQ mutation affecting both dermal and leptomeningeal vessels — producing a facial port wine stain, brain surface capillary-venous malformations causing seizures and progressive neurological injury, and glaucoma.
What causes it?
A somatic activating GNAQ mutation (p.R183Q) — the same gene as isolated capillary malformations. In SWS, the mutation occurs early enough in embryonic development to affect both dermal and leptomeningeal vessels. The mutation is mosaic — present in affected tissues, absent from blood. Not heritable: a parent with SWS does not transmit it to children.
How does it present?
The facial port wine stain is present at birth. Seizures typically begin in the first year of life — often focal, contralateral to the side of brain involvement. Seizures may be refractory and can trigger Todd’s paralysis (temporary post-ictal weakness). Progressive features over time: cognitive impairment (variable), behavioral challenges, headaches, hemiplegia in extensive cases. Neurological burden depends substantially on extent of leptomeningeal involvement and seizure control.
How is it diagnosed?
| MRI Brain with gadolinium | Essential. Leptomeningeal enhancement is the diagnostic finding. Cortical atrophy and calcification develop over time. |
| EEG | Characterizes seizure pattern. Identifies affected hemisphere. |
| Ophthalmologic exam | IOP measurement, gonioscopy, fundoscopy. Begin in the neonatal period for at-risk patients. |
| GNAQ tissue testing | Confirms molecular diagnosis when needed. Not required for clinical diagnosis in typical presentations. |
What are the treatment options?
| Antiseizure medications | First-line neurological management. Seizure control is the primary goal — uncontrolled seizures accelerate cortical damage. |
| Low-dose aspirin | Evidence in some studies for reducing stroke-like episodes. Specialist guidance required. |
| Hemispherectomy | For medically refractory seizures with focal unilateral involvement. Carefully selected patients. |
| Glaucoma management | Medical or surgical. Lifelong monitoring required. |
| PDL for facial CM | Treats the surface capillary malformation only. Does not affect leptomeningeal or ocular involvement. ~2% complete clearance. |
| Early intervention | Developmental, physical, and occupational therapy. Early intervention associated with better developmental outcomes. |
What are the risks if undertreated?
Uncontrolled seizures drive neurological deterioration — each episode contributes to cortical ischemia and accelerates atrophy in the affected hemisphere. Untreated glaucoma causes progressive irreversible vision loss. Stroke-like episodes occur from the chronic ischemia mechanism even without seizures.
How does SWS differ from isolated port wine stain and KTS?
| Feature | SWS | Isolated CM | KTS |
|---|---|---|---|
| Brain involvement | Yes — defining | No | No |
| Glaucoma risk | Yes — ~30-70% | No | No |
| Seizures | Yes — ~75-90% | No | No |
| Limb hypertrophy | No | No | Yes |
| Flow type | Slow-flow | Slow-flow | Slow-flow |
| Genetic driver | GNAQ | GNAQ | PIK3CA |
| Core management | Neurology + ophthalmology | Dermatology / laser | VA multidisciplinary |
Source References
| GNAQ / SWS | Shirley MD et al. NEJM 2013 |
| Neurological management | Comi AM — Sturge-Weber and stroke-like episodes |
| Aspirin | Lance EI et al. — aspirin in SWS |
| PDL | Chapas AM et al. — PDL outcomes in CM (~2% complete clearance) |
| Full spectrum | care4rare.blog — PWS Addendum A: Sturge-Weber Syndrome |
| ISSVA | issva.org/classification — SWS under syndromic CM |