Neurovascular conflict (NVC) is the most common cause of trigeminal neuralgia, which paved the way for the success of microvascular decompression. While the correlation between severe neurovascular conflict and trigeminal neuralgia is established, a comprehensive understanding of the qualitative measures of trigeminal nerve distortion is lacking. Leveraging advanced imaging technology, we investigated the three-dimensional (3D) morphology of the trigeminal nerves in patients with trigeminal neuralgia, aiming to correlate deformities with the side, distribution of pain, and intraoperative findings.

Patients with trigeminal neuralgia and an high-resolution magnetic resonance imaging (MRI) utilizing 3D constructive interference in steady state (CISS) were selected. Blinded evaluations of MRI scans were conducted, and trigeminal nerves were meticulously segmented using Brainlab Elements Software. The study included 41 patients with trigeminal neuralgia. Length, volume, and deformities in axial, sagittal, and coronal planes were blindly analyzed for each nerve.

The average age at the time of MRI was 58 years, with a mean pain duration of 4 years. Continuous pain components were observed in 9 patients, 4 patients had concomitant multiple sclerosis, and 9 patients presented with preoperative hypaesthesia. The mean slice thickness of scans was 0.5 mm (range 0.3-0.7). Painful side exhibited severe coronal deformities in 17%, moderate in 22%, and mild in 44% of patients, while non-painful side had 17% moderate, and 51% mild deformities. Sagittal deformities was present in 56% of nerves on the painful side, and in 39% of the nerves on the non-painful side. Coronal and sagittal deformities were associated with side and distribution of pain. Arachnoid adhesions contributed in sagittal and axial deformity of the trigeminal nerve.

This study establishes that deformities in coronal, sagittal, and axial planes of the trigeminal nerve are associated factors in the pathogenesis of trigeminal neuralgia. Understanding these morphological nuances contributes to a better comprehension of the disorder and may aid in refining treatment approaches.