Intracranial hypertension in Sturge-Weber/Klippel-Trenaunay-Weber overlap syndrome due to impairment of cerebral venous outflow.

Klippel-Trenaunay-Weber syndrome (KTWS) is a rare mesodermal phakomatosis characterized by (1) cutaneous haemangiomata (usually unilateral and involving an extremity) (2) venous varicosities and (3) osseous and soft tissue hypertrophy, also of the affected limb. Sturge-Weber Syndrome (SWS), also a mesodermal phakamatosis, is characterized by meningofacial angiomatosis with cerebral calcification. Overlap between KTWS and SWS is recognized. We describe the case of a young woman with features of both KTWS and SWS who presented with symptoms of acute intracranial hypertension, including headache, vomiting and marked visual impairment. Cerebral angiography revealed paucity of the superficial cortical veins overlying one of the cerebral hemispheres and centripetal venous drainage via small deep venous channels. Based upon this pattern of cerebral venous outflow, we postulate a mechanism to explain the acute episode of intracranial hypertension.