Anaesthetic management of a parturient with a colloid cyst of the third ventricle

A colloid cyst in the third ventricle near the foramen of Monroe can obstru ct cerebrospinal fluid (CSF) flow from the lateral ventricles. Any change i n the CSF pressure on either side of the cyst can lead to displacement and thus precipitate acute hydrocephalus. Management of the confinement of a pa tient with a colloid cyst must therefore aim to minimize changes in CSF pre ssure. We describe our management of a patient with a small colloid cyst wh o was permitted to labour with the assistance of patient-controlled epidura l analgesia. The available alternatives are discussed.