The Importance of Trigeminal Cisternography in the Percutaneous Treatment of Idiopathic Trigeminal Neuralgia.

Objective: To investigate whether the tip of the spinal needle was accurately positioned within the trigeminal cistern (TC) in patients with idiopathic trigeminal neuralgia undergoing percutaneous treatments through the foramen ovale. Methods: Transovale trigeminal cisternography (TOTC) was performed to ascertain the location of the spinal needle tip within the TC in 35 patients who underwent percutaneous retrogasserian glycerol rhizotomy (PRGR) procedures and 112 patients who underwent percutaneous controlled radiofrequency trigeminal rhizotomy (PCRF-TR) where the preganglionic trigeminal rootlets (PGTRs) could not be stimulated by radiofrequency. When TOTC revealed that the needle tip was in the subtemporal subarachnoid compartments, the needle insertion site at the foramen ovale was adjusted and redirected toward the dorsum sellae under intraoperative fluoroscopy guidance. Results: In 17 (15%) patients who underwent PCRF-TR, PGTR stimulation was unsuccessful, and TOTC revealed the needle tip within the subtemporal subarachnoid space. In five (14%) patients who underwent PRGR, the needle tip was inside the subtemporal subarachnoid space, according to the TOTC evaluation. Conclusion: The findings of this study underscore the significance of TOTC in both PRGR and PCRF-TR procedures, particularly when PGTRs cannot be stimulated by the radiofrequency electrode.