Trigeminal nerve-artery contact in people without trigeminal neuralgia: MR study

Background: Neurovascular conflict is regarded as the most common cause of idiopathic trigeminal neuralgia. It is suspected that a blood vessel in contact with the root entry zone of a trigeminal nerve causes its irritation. The aim of the study was to evaluate how signs of neurovascular conflict can be found in people without trigeminal neuralgia.
Material and Methods: The study was conducted retrospectively. The authors analyzed MR examinations of 60 patients (120 nerves), aged 22–77 years, who did not have trigeminal neuralgia or related symptoms. Nerve-artery contact at the root entry zone of a trigeminal nerve, nerve deformation, and atrophy were searched for in angio-3D-TOF images (slice thickness: 1 mm).Results: Contact between a trigeminal nerve and an artery was found in 30 cases (25% of nerves). The blood vessel was parallel to the nerve root in 14 cases (11.7%) and crossed it at a right or acute angle in 15 cases (12.5%). Contact between artery and atrophic nerve was found in one case. Modeling of the trigeminal nerve by an artery was not found.
Conclusions: Contact between a trigeminal nerve root and an artery in the prepontine cistern is a frequently seen anatomical variant. Therefore, detection of such a variant is not equivalent to finding the cause of a patient’s complaints.

Keywords: Adult, Aged, 80 and over, Arteries - anatomy & histology, Magnetic Resonance Imaging, Trigeminal Nerve - pathology, Trigeminal Neuralgia - pathology