Sturge-weber syndrome: a unified pathophysiologic mechanism.

According to a new, unifying view of the pathogenesis of Sturge-Weber syndrome and related syndromes, signs and symptoms all arise from localized primary venous dysplasia, with effects of venous hypertension transmitted to nearby areas via persisting communicating venous passageways and compensatory collateral venous channels. Port-wine stains result from a vascular disorder rather than a neural disorder. Symptoms depend upon the extent and location of the venous dysplasia. This hypothesis is supported by published data and by original observations and Doppler ultrasonographic studies of orbital venous flow in patients with the Sturge-Weber syndrome. This new understanding of underlying pathophysiology also elucidates the mechanism for tissue hypertrophy. Therapies aimed at obliterating port-wine stains to minimize the cosmetic blemish will reduce collateral venous blood-flow passageways. In some instances, this reduction may worsen blood stasis within the brain and potentially exacerbate neurologic symptoms.