Transoval trigeminal cisternography.

A new water-soluble contrast medium, metrizamide (Amipaque) was used to visualize the subarachnoid space within Meckel's cave. By a needle introduced through the foramen ovale, successful filling of the trigeminal cistern was accomplished in 48(80%) of 60 patients. Transoval trigeminal cisternography offers a possibility to control the position of the tip of the needle in various blocking procedures of the trigeminal ganglion, and may also be used for target localization in stereotactic radiosurgery in the treatment of trigeminal neuralgia.