Sturge-Weber Syndrome

KEY FACTS

TERMINOLOGY

• Synonyms: Sturge-Weber-Dimitri, encephalotrigeminal

angiomatosis

IMAGING

• Imaging features are pial angioma with sequelae of chronic

venous ischemia

○ Pial angiomatosis unilateral (80%), bilateral (20%)

○ Cortical Ca++, atrophy, and enlarged ipsilateral choroid

plexus

○ "Tram-track" calcification in cortex (not angioma)

• Early: Transient hyperperfusion → "accelerated" myelin

maturation

• Late: Increased signal in region of gliosis and decreased

cortical signal in regions of calcification

• Early: Serpentine leptomeningeal enhancement, pial

angiomatosis of subarachnoid space

• SWI delineates enlarged, tortuous medullary white matter

veins providing collateral drainage to deep veins

PATHOLOGY

• Somatic mutation of GNAQ causes Sturge-Weber syndrome

and nonsyndromic "port-wine" stains

CLINICAL ISSUES

• "Port-wine" stain, seizures, hemiparesis

• Rare: 1:20,000-50,000

• ↑ extent of lobar involvement and atrophy leading to

increased likelihood of seizures

• Seizures cause further brain injury

DIAGNOSTIC CHECKLIST

• FLAIR C+ most sensitive sequence to detect pial angioma

(especially in infancy)

• T2 hypointensity of white matter underlying angioma is

clue to early diagnosis

• Identification of retinal angioma critical in subtle/early cases

(Left) Coronal graphic shows

extensive pial angiomatosis ſt

surrounding affected gyri,

prominent deep medullary

collaterals ﬈, shunt venous

blood to deep system,

enlarged ipsilateral choroid

plexus ﬊, and atrophy of the

right cerebral hemisphere.

(Right) Coronal T1C+ MR in an

8 year old with Sturge-Weber

syndrome (SWS) shows

atrophy of the right

hemisphere with vessels st

crossing the prominent

subarachnoid space from the

pial angioma ﬇. Note

enlarged ipsilateral choroid

plexus ſt.

(Left) T1 C+ FS scan in another

patient with SWS shows

enlarged convexity sulci that

are entirely filled with an

intensely enhancing pial

angioma ſt. (Right) T2* SWI

in the same case shows

multiple enlarged, tortuous

medullary veins ﬈ draining

the left hemisphere into the

deep venous system. There is a

paucity of normal cortical

veins in SWS, so the enhancing

pial angioma must drain into

the ipsilateral subependymal

veins and choroid plexus.

Brain: Pathology-Based Diagnoses: Malformations,

Trauma, and Stroke

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