Cavum septi pellucidi as a cause of shunt dysfunction.

Cavum septi pellucidi and cavum vergae are generally asymptomatic fluid collections between the leaves of the septum pellucidum and are present in approximately 15% of adult brains. There are occasional reported cases of symptomatic cysts arising in this area. This paper reports a case in which a cavum septi pellucidi was a cause of shunt malfunction. On an air ventriculogram this condition was initially confused with a subdural collection.