1. 2022;25;E293-E298Anatomy of the Trigeminal Nerve and Its Clinical Significance Via Fusion of Computed Tomography and Magnetic Resonance Imagery
   Research Study
   YaJing Chen, MD, Xiaolan Liu, MD, ShuangShuang Xu, MD, and Bing Huang, MD.

BACKGROUND: The Gasserian ganglion (GG) is the primary neuronal aggregation area of the trigeminal nervous system and the epidural structure outside the central nervous system, thus, it has become the most commonly used target for minimally invasive treatment of trigeminal neuralgia (TN). Whether it is the classic trigeminal radiofrequency treatment or GG balloon compression therapy, the intervention target is the GG. The anatomy and imaging anatomy of the GG of the trigeminal nerve is of great importance in the minimally invasive treatment of TN.

OBJECTIVE: To study the anatomy of the trigeminal nerve and multimodal image fusion, and to provide a basis for a clinical minimally invasive interventional treatment forTN.

STUDY DESIGN: Review, clinical research study.

SETTING: Department of Anesthesiology and Pain Medical Center, Jiaxing, China.

METHODS: Dissect the general structure of the trigeminal nerve and its positional relationship with adjacent structures, and use computed tomography (CT) and magnetic resonance imaging (MRI) to observe the trigeminal nerve, and then, perform a fusion of the CT/MR images.

RESULTS: The GG of the trigeminal nerve is located in Meckel’s cave of the middle cranial fossa, and the 3 branches of the nerve fibers are intertwined. CT could only clearly show the bony structures adjacent to the GG, rather than the GG in the body, which was inconsistent with MR images. The bony structure was blurred, while the Meckel’s cave and nerve roots, where the trigeminal nerve is located, could be clearly distinguished. Fusing the CT/MR images could provide 2 complementary advantages.

LIMITATIONS: It does not prove the the balloon position thought to be a “dumbbell” shape is adequate for the successful treatment.

CONCLUSION: Based on the anatomical structure and position of the trigeminal nerve, it is difficult to achieve highly selective branch treatment of TN with radiofrequency in the GG. For the treatment of TN with percutaneous microballoon compression on the GG, the balloon catheter should be placed in Meckel’s cave. While it is not easy to insert into Meckel’s cave, the depth of the balloon catheter should be that the distal end is flush with the top of the temporal bone petrous cone.

KEY WORDS: Computed tomography, magnetic resonance imaging, image fusion, trigeminal neuralgia