Identification of Meckel cave during percutaneous glycerol rhizotomy for tic douloureux.

A new percutaneous treatment of tic douloureux has been developed . Transovale injection of glycerol into the retrogasserian trigeminal fibers in Meckel cave results in complete pain relief in 77%-89% of patients [1-3]. The major advantages of percutaneous retrogasserian glycerol rhizotomy include simplicity, radiograph ic confirmation of accurate need le placement, and a much reduced incidence of postoperative facial sensory loss. The technique is dependent upon proper intraoperative recognition of the trigeminal cistern for placement of the glycerol, which is identified in postoperative radiographs by tantalum dust mixed with the glycerol as a permanent marker of Meckel cave .