Case of overlap between Sturge-Weber and Klippel Trenaunay syndromes

A 9-year-old female child presented with history of seizures and right sided hemiparesis. She had extensive capillary telangiectasia over left side of her body.

Left cerebral hemisphere appears smaller as compared to the right. The calvarium on the left side is thickened.

Extensive leptomeningeal enhancement was seen along the cortical sulci of the entire left.

cerebral hemisphere, suggestive of leptomeningeal angiomatosis.

There was hypertrophy of choroid plexus of the left lateral ventricle which showed intense post-contrast enhancement.

Extensive areas of T2 shortening showing blooming on SWI images were seen involving cortex and subcortical white matter of left frontoparietal and occipital lobes with relative sparing of the temporal lobe. Serpiginous areas of calcification are seen in a few of these areas; best seen on CT images.

Multiple dilated tortuous vessels are seen in the superior aspect of quadrigeminal cistern.

Background 

Sturge–Weber syndrome is a sporadic congenital neurocutaneous disorder affecting brain, meninges (angiomatous lesion of leptomeninges), with a coexistent capillary malformation over the skin of face typically along ophthalmic (V1) and maxillary (V2) distributions of trigeminal nerve and [1].

It is believed to be caused by the persistence of a vascular plexus around the cephalic portion of neural tube. This plexus develops during the sixth week of intrauterine development but normally undergoes regression during the ninth week. [2]

The sclera/choroid of the eyes is also affected resulting in glaucoma due to episcleral venous hypertension.

Klippel-Trenaunay Syndrome is a rare mesodermal phakomatosis. It comprises of a triad of vascular malformation involving a limb, venous varicosities of the same limb, and bone/ soft tissue hypertrophy of the affected extremity [3].

The exact pathogenesis of these syndromes is still not clear. However, the widely accepted pathophysiogenetic cause is mutation of GNAQ gene in Sturge–Weber and mutations of PIK3CA in Klippel–Trenaunay syndromes [4]. These genes play a key role in angiogenesis and their mutations result in extensive vascular malformations.

Very few cases of overlap between KTS and SWS have been reported in the literature.

Clinical Perspective 

The most common clinical manifestation of Sturge weber syndrome is refractory seizures beginning in the first few years of life which are often associated with developmental delay, hemiplegia/hemiparesis and hemianopsia. The choroidal angioma may cause retinal detachment, buphthalmos or glaucoma.

The most common manifestation of Klippel Trenaunay syndrome is cutaneous capillary malformations predominantly involving a limb resulting in unilateral limb enlargement.  Varicose veins are a common occurrence that results in complications like thrombophlebitis and venous embolism.

Visceral manifestations include bowel and bladder haemorrhage due to underlying angiomas.

Imaging Perspective

Both CT and MRI are useful, however, MRI is the investigation of choice to detect and characterize the extent of Pial angioma.

Prominent leptomeningeal enhancement is seen in the affected hemisphere with enlarged ipsilateral choroid plexus.

T2 hypointense signal is seen in the underlying white matter due to pathognomonic tram-track calcification.

Dilatation of trans parenchymal veins communicating between superficial and deep venous systems is seen in some cases. Few abnormal deep venous channels can also be seen.

Outcome 

The mainstay of management of Sturge weber syndrome revolves around control of seizures, monitoring and treatment for glaucoma and physical rehabilitation for motor hemiparesis (1).

Management of Klippel Trenaunay syndrome primarily revolves around prevention of deep venous thrombosis by anticoagulants, stockings and pneumatic compression devices to the enlarged extremity. Percutaneous sclerotherapy and surgical stripping can be done for refractory superficial venous varicosities.

Take-Home Messag /Teaching Points

Patients with Sturge-Weber and Klippel-Trenaunay syndromes should have a timely diagnosis and early surveillance for associated deep venous malformations.

They also require long-term follow up to control and treat the associated ocular, skeletal and neurological complications due to underlying vascular malformations.