Sturge-Weber syndrome (SWS)

David Goldemund M.D.
Updated on 09/11/2023, published on 02/11/2023
  • Sturge-Weber syndrome (SWS), also known as encephalotrigeminal angiomatosis, is a neurocutaneous disorder manifested by leptomeningeal and facial angiomas
    • the facial lesion, also referred to as a nevus flammeus or port-wine birthmark (PWB), is the hallmark of the disease
      • it is typically located in the ophthalmic and maxillary distributions of CN V with a sharp midline demarcation
      • it is caused by dilated dermal capillaries
    • leptomeningeal angiomatosis results in vascular steal affecting the adjacent cortex and white matter, causing localized ischemia
    • unilateral involvement occurs in ~ 80% of cases
  • SWS is not typically characterized by stroke, but the venous malformation may predispose to venous (hemorrhagic) infarction (due to venous or sinus thrombosis)
  • SWS-related stroke-like episodes may cause DDx difficulties (stroke mimics)
Port wine stain in Sturge-Weber syndrome


  • SWS is a sporadic disease not associated with hereditary transmission (unlike other neurocutaneous disorders, such as neurofibromatosis or tuberous sclerosis)
  • SWS occurs due to somatic mutations that are not inherited; mutation appears to cause alterations in the regulation of the structure and function of blood vessels, vascular innervation, and expression of extracellular matrix and vasoactive molecules
    • an associated gene mutation has been identified in the GNAQ gene (p.Arg183Gln) on chromosome 9 (at 9q21.2)
      • development of isolated port wine stains or SWS depends on what stage of embryonic development is affected
      • somatic pathogenic variants in GNAQ occurring at a later stage in embryogenesis may affect only precursors of vascular endothelial cells and lead to nonsyndromic port wine stains, while those occurring at an earlier stage affect a variety of precursor cells and cause SWS
    • atypical SWS associated with variants in GNA11 has been reported


SWS can be classified according to the presence/absence of facial and leptomeningeal angiomas (Roach, 1992):

  • type I: classic syndrome (most common) with both facial and leptomeningeal angiomas ± glaucoma
    • seizures usually occur within the first year of life
    • in rare cases, the facial and brain involvement is bilateral
    • mental and physical development is impaired to varying degrees
  • type II: facial angioma without evidence of intracranial disease ± glaucoma
  • type III: isolated leptomeningeal angioma with no facial involvement, usually without glaucoma

Clinical presentation

  • a congenital facial cutaneous capillary malformation (also known as port wine stain or nevus flammeus)
    • almost always present (95%)
    • usually involves the V1 or V2 portion of the trigeminal nerve
    • the nevus is most commonly unilateral and ipsilateral to the intracranial abnormality
  • childhood epilepsy (up to 90% of cases)
    • seizures usually occur in the first few years of life and are often associated with developmental delay and hemispheric symptoms, including hemiplegia/hemiparesis and hemianopsia
    • often refractory to medical therapy
  • ocular manifestations
    • choroidal or (epi)scleral angiomatosis
    • hemangioma-like superficial changes in the eyelid
    • retinal detachment
    • tortuous retinal vessels
    • buphthalmos (enlarged eyeball due to increased intraocular pressure)
    • glaucoma
  • developmental delay, learning disabilities, attention deficit hyperactivity disorder
  • macrocephaly
  • stroke-like episodes
    • weakness or paresthesias on one (or both) sides of the body
    • a wide range of recovery times to baseline motor function was reported  (1 minute to 6 months, median: 24 hours)
    • exact etiology is unknown; it may be triggered by seizures or migraines, but it may also develop without any evidence of epilepsy
    • brain MRI rarely shows permanent infarcts typical for cerebrovascular events of arterial origin
  • hemorrhagic venous infarction (rare)

Factors suggesting a progressive course of cortical damage in SWS include:

  • initial focal seizures progressing to frequent secondarily generalized seizures
  • increasing seizure frequency and duration despite the use of antiseizure medication (ASMs)
  • increasing duration of a transient postictal deficit
  • increase in focal or diffuse atrophy (demonstrated by serial neuroimaging)
  • progressive calcifications
  • development of hemiparesis
  • cognitive deterioration

Diagnostic evaluation


  • gyriform calcifications of subcortical white matter
  • CT/MRI has replaced this method
  • subcortical calcifications associated with parenchymal atrophy
  • enlarged ipsilateral choroid plexus
  • orbital choroidal hemangiomas
  • asymmetric cavernous sinus enlargement
Sturge-Weber syndrome cases with extensive unilateral hemispheral calcifications
  • T1: usually normal, atrophy occurs at an older age
  • T1 C+ (Gd) 
    • leptomeningeal enhancement in the affected area due to congested internal cerebral veins (pial angiomatosis) resulting in venous congestive ischemia
    • later, the angioma may lose its enhancement
    • enlarged ipsilateral choroid plexus Sturge-Weber syndrome - enlarged chorid plexus and leptomeningeal enhancement
    • dilatation of transparenchymal veins communicating between the superficial and deep venous systems
  • T2 – low signal in white matter near to the angioma represents:
    • calcifications
    • abnormal deep venous drainage (with flow voids)
  • GE/SWI/EPI:  subcortical hypointense lesions
  • MR spectroscopy: decreased NAA
Sturge-Weber syndrome cases showing unilateral leptomeningeal enhancement on postcontrast MRI
  • angiography demonstrates absent superficial cortical veins with abnormal and enlarged deep venous drainage
  • decreased arterial blood flow velocity and increased pulsatility were found in the MCA and PCA, suggesting high resistance
  • these results may reflect high venous stasis, potentially contributing to chronic hypoperfusion

Other methods

  • ophthalmologic examination (glaucoma, etc.)
  • cerebrospinal fluid (CSF) examiantion
    • protein may be elevated, presumably secondary to microhemorrhage
  • electroencephalography (EEG)

Differential diagnosis

DDx of intracranial calcifications + cerebral hemiatrophy + leptomeningeal enhancement

  • cerebral arteriovenous malformation (AVM)
  • infection
    • TORCH infection (vertically transmitted infections that may cause severe fetal anomalies or fetal loss)
      • Toxoplasmosis
      • Other infections (e.g., Varicella-Zoster Virus, HIV, Syphilis)
      • Rubella
      • Cytomegalovirus (CMV)
      • Herpes Simplex Virus (HSV)
    • neurocysticercosis
  • PHACE syndrome
    • also known as cutaneous hemangioma–vascular complex syndrome or Pascual-Castroviejo type II syndrome
  • radiation-induced injury
  • Gobbi syndrome
    • combination of celiac disease, epilepsy, and bioccipital calcifications
  • calcification secondary to intrathecal methotrexate therapy and meningitis
  • Dyke-Davidoff-Masson syndrome
    • one cerebral hemisphere is partially or completely atrophic as a result of an intrauterine or perinatal carotid artery infarction


  • seizure control (ASM ± surgery)
  • symptomatic and prophylactic treatment of headaches
  • glaucoma treatment
  • laser therapy for skin lesions

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Sturge-Weber syndrome