Pseudotumor cerebri.

Pseudotumor cerebri (PTC) is a syndrome of increased intracranial pressure without hydrocephalus or mass lesion and with normal cerebrospinal fluid (CSF) composition. Although often considered to be "idiopathic," detailed investigation has revealed a high incidence of venous outflow abnormalities in PTC syndrome patients. The thought that elevated intracranial venous sinus pressure is a "universal mechanism" for PTC syndrome of varying etiologies has been called into question by a study indicating that the increased venous pressure in idiopathic PTC patients is caused by the elevated intracranial pressure and not the reverse, suggesting that "the chicken is the CSF pressure elevation and the egg is the venous sinus pressure elevation." Vitamin A toxicity may play a role in the pathogenesis of idiopathic PTC. The treatment of PTC has two major goals: the alleviation of symptoms and preservation of visual function. When medical therapy fails or when visual dysfunction deteriorates, surgical therapies for PTC should be considered. The two main procedures performed include lumboperitoneal shunt and optic nerve sheath fenestration. Because of the association of PTC with venous sinus hypertension, some authors are considering venous sinus stenting for refractory cases of PTC. It is still unclear if primary treatment of the observed venous stenosis benefits patients with idiopathic PTC. This should be no surprise, as it is not certain whether the stenoses are the cause or the result of idiopathic PTC.