To discuss the correlation between painful range of trigeminal neuralgia (TN) and location of neurovascular compression (NVC).

A total of 165 patients with single branch TN enjoying complete clinical data and having definite offending vessels were enrolled into this study; these patients underwent microsurgical treatment in cerebellopontine angle (CPA) area via suboccipital retrosigmoid approach in our hospital from March 2017 and June 2019; 22 patients had branch I TN, 84 patients had branch II TN, and 59 patients had branch III TN. The cistern part of trigeminal sensory root (CPA cistern part) was divided into four directions: cephalic, caudal, ventral and dorsal sides. The root entry zone (REZ) of trigeminal nerves was divided into four quadrants: cephalic-ventral, cephalic-dorsal, caudal-ventral and caudal-dorsal quadrants.

(1) In patients with branch I TN, 8 patients had location of NVC in the cistern part of CPA, including 5 in the cephalic side, two in the ventral side and one in the dorsal side; main offending vessels were superior cerebellar artery (SCA, n=7), mainly with cephalic compression. Another 14 patients had location of NVC in the REZ, including 11 in the cephalic-ventral quadrant, 2 in the cephalic-dorsal quadrant and one in the caudal-ventral quadrant; main offending vessels were SCA (n=11), mainly with cephalic-ventral compression (n=8). (2) In patients with branch II TN, 29 patients had location of NVC in the cistern part of CPA, including 16 in the ventral side, 10 in the dorsal side, 2 in the cephalic side and one in the caudal side; main offending vessels were SCA (n=22), mainly with ventral and dorsal compression. Another 55 patients had location of NVC in REZ, including 26 patients in the cephalic-dorsal quadrant, 20 in the cephalic-ventral quadrant, 6 in caudal-dorsal quadrant and 3 in the caudal-ventral quadrant; main offending vessels were SCA (n=41), mainly with cephalic-dorsal compression (n=23) and cephalic-ventral compression (n=17). (3) In patients with branch III TN, 26 patients had location of NVC in the cistern part of CPA, including16 in the caudal side and 10 in the dorsal side; main offending vessels were SCA (n=7), mainly with dorsal compression. Another 33 patents had location of NVC in the REZ, including 25 in the cephalic-dorsal quadrant, 6 in the the caudal-dorsal quadrant and 2 in the caudal-ventral quadrant; main offending vessels were SCA (n=22), mainly with cephalic-dorsal compression.

The location of NVC in patients with branch I TN is mainly in the cephalic direction of the cistern part of CPA and the cephalic-ventral quadrant of REZ. The location of NVC in patients with branch II TN is mainly in the ventral and dorsal direction of the cistern part of CPA, and cephalic-dorsal and cephalic-ventral quadrant of REZ. The NVC in patients with branch III TN only locates in the caudal and dorsal direction of the cistern part of CPA, and mainly in the cephalic-dorsal quadrant of REZ. In the REZ or cistern part of CPA, SCA is always the main offending vessel.

Trigeminal neuralgia; Painful range; Neurovascular compression; Location; Offending vessel