A 3-year-old girl is referred to a pediatric neurologist because of a history of developmental delay and focal seizures since birth that are no longer being well controlled with two antiseizure medications. On physical exam, the neurologist notes a large bilateral port-wine stain on the face (Figure 207-1). The neurologist suspects that the child has Sturge-Weber syndrome and orders brain imaging and an ophthalmologic exam. The MRI reveals leptomeningeal angiomas and the ophthalmologist diagnoses glaucoma. The diagnosis of Sturge-Weber syndrome is confirmed and education is provided to the parents on this condition. The child’s anti-epileptic medications are maximized and her glaucoma is treated by the ophthalmologist.

Sturge-Weber syndrome (SWS) is a sporadic congenital neurocutaneous syndrome that is characterized by facial capillary malformation known as a port-wine stain, ocular abnormalities including glaucoma and choroidal hemangioma, and leptomeningeal angiomas. Seizures, developmental delay and glaucoma comprise the major clinical features. SWS is associated with mutations in the GNAQ gene.

Encephalotrigeminal angiomatosis and encephalofacial angiomatosis.

Port-wine stains are also called nevus flammeus.

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  SWS occur sporadically at a rate of 1 per 20,000 to 50,000 newborns and in equal frequency in both genders.¹

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  SWS is caused by somatic activating mutations in GNAQ gene, as confirmed by a whole-genome sequencing study that examined skin and brain tissue samples.¹

  
  
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  GNAQ encodes for G-alpha-q, a G-protein alpha subunit that acts as a mediator between G-protein coupled receptors and downstream signaling molecules.

  
  
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  In fetal ectodermal tissue, this mutation is thought to cause inappropriate maturation of capillaries, thus leading to capillary malformations.¹ The port-wine stain is due to a dilation of capillaries and venous blood vessels in the dermis rather than a proliferation of the capillaries.²

Clinical Features

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  Physical manifestations of SWS can be divided into cutaneous, ocular, and neurologic. The diagnosis is usually made based on the presence of the facial capillary malformations and leptomeningeal angiomas.²

  
  
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  Cutaneous:

  
  
  
  
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    The most obvious sign of SWS is the facial capillary malformation, known as a port-wine stain, due to its color (Figures 207-1 to 207-3).

    
    
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    Note that a capillary malformation is not the same as a cutaneous hemangioma even though these are often confused as the same entity. While there are ocular and CNS angiomas present in SWS, the port-wine stain is not a hemangioma.

    
    
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    It normally involves at least the distribution of the ophthalmic branch of the trigeminal nerve, overlying the forehead and the upper eyelid.

    
    
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    Although it usually does not cross the midline, those with bilateral port-wine stains are more likely to have cerebral involvement.^2,3

  
  
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  Neurological:

  
  
  
  
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    Leptomeningeal capillary-venous malformations, or angiomas can occur in children with SWS, usually ipsilaterally to the port-wine stain in the parietal or occipital areas (Figure 207-4). Underlying brain parenchyma may be atrophic and calcified.²

    
    
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    Seizures are the usual presenting neurologic manifestation of this syndrome and can occur in 23 to 83 percent of patients. They can occur at any age but often manifest before 2 years of age. Seizures are typically focal motor seizures, but secondary generalization can occur. Infantile spasms are less common but can also occur. Seizures often present initially during a febrile episode. They can be more severe in patients with bilateral leptomeningeal angiomas.²

    
    
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    Developmental delay is present in approximately half of these patients. Degree of handicap is usually correlated with younger age at onset of seizures.

    
    
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    Recurrent headaches are also common in these patients.

    
    
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    Stroke-like episodes can occur, with hemiparesis or visual field defects.

  
  
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  Ocular:

  
  
  
  
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    Glaucoma, the most common ocular manifestation of SWS, develops in 30 to 70 percent of patients with SWS in some studies, and is usually ipsilateral to the port-wine stain. It can occur early in childhood and has an insidious onset. For this reason, any newborn or child presenting with a port-wine stain in the V1 distribution of the trigeminal nerve should be referred for a complete ophthalmologic exam.²

    
    
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    Choroidal hemangioma occurs in many patients with SWS and is also usually ipsilateral to the port-wine stain (Figure 207-5). Over time, these lesions can cause retinal pigment epithelium degeneration, fibrous metaplasia, or cystic retinal degeneration, leading to vision loss. The presence of a choroid hemangioma almost always indicates presence of leptomeningeal hemangiomas.²