Sturge-Weber syndrome
Sturge-Weber syndrome is a congenital, nonhereditary neurocutaneous disorder caused by a somatic mosaic activating mutation in the GNAQ gene, producing a facial port-wine capillary malformation, an ipsilateral leptomeningeal capillary-venous angioma with seizures and possible hemiparesis, and episcleral hemangioma with early-onset glaucoma. Diagnosis requires brain MRI with contrast in a patient with a high-risk facial birthmark, and management centers on prompt antiseizure treatment, pulsed-dye laser for the birthmark, low-dose aspirin in selected patients with brain involvement, and lifelong monitoring for glaucoma and neurodevelopmental decline.
- Topic reviewThe full article, organized the way the exam asks it.
- ABIM-format MCQsVignettes with an explanation for every wrong answer.
- Key factsThe numbers and thresholds worth memorizing, up front.
- AI tutorMedBrain answers the question you're stuck on.
What this article covers
- Overview
Definition: Sturge-Weber syndrome is a congenital, nonhereditary neurocutaneous disorder, also called encephalotrigeminal angiomatosis, caused by a somatic mosaic activating mutation in one copy of the GNAQ gene.
- Epidemiology
Congenital and sporadic: Sturge-Weber syndrome is present from birth and arises from a sporadic somatic mosaic mutation rather than from inherited transmission.
- Risk factors
High-risk birthmark location: a port-wine birthmark involving the forehead from the midline to a line joining the outer canthus and the upper ear carries the strongest association with brain and eye disease.
- Pathophysiology
Somatic mosaic GNAQ mutation: an activating mutation in one copy of the GNAQ gene arising after fertilization produces a mosaic pattern of affected tissue derived from neural crest cells.
- Clinical features
Facial capillary malformation (port-wine stain): present at birth, usually in the V1 or V2 trigeminal distribution; this finding alone does not establish the diagnosis of Sturge-Weber syndrome.
- Differential diagnosis
Tuberous sclerosis complex: presents with seizures (often infantile spasms), a cardiac rhabdomyoma murmur, and a leathery shagreen patch or ash-leaf hypopigmented macules, unlike the port-wine…
- Diagnosis
Diagnostic basis: Sturge-Weber syndrome is diagnosed when a facial port-wine capillary malformation is accompanied by an ipsilateral leptomeningeal capillary-venous malformation of the brain and eye…
- Management
First step, for the facial birthmark itself: offer pulsed-dye laser treatment, the first-line light-based treatment for a facial port-wine birthmark, which can begin in infancy and usually requires multiple sessions.
- Complications
Glaucoma and vision loss: unrecognized or undertreated elevated intraocular pressure from the episcleral hemangioma can progress to permanent optic nerve damage and vision loss.
- Prognosis
Variable, tied to the extent of brain involvement: outcome ranges from an isolated, cosmetically significant birthmark with no neurologic disease to severe epilepsy, hemiparesis, and intellectual…
- Prevention
Early identification of high-risk birthmarks: recognizing a port-wine stain in the high-risk forehead-to-canthus-to-ear distribution, especially with upper-eyelid or bilateral involvement, at birth…
Read the whole article
Subscribing to Internal Medicine opens every article, the full question bank and MedBrain, on the web, iPhone and Android.