Trigeminal neuralgia: When does neurovascular contact turn into a conflict?

Abstract

Background: The most common cause for trigeminal neuralgia is contact of the trigeminal nerve with an offending vessel which is also observed routinely in many asymptomatic patients. Therefore, the aim of this study was to determine when an asymptomatic Neuro Vascular Contact (NVC) turned into a neurovascular conflict and made the patient symptomatic. Methods: All patients who underwent Magnetic Resonance Imaging (MRI) brain with clinical diagnosis of trigeminal neuralgia formed the study group and all cases of sensorineural hearing loss formed the control group. Results: Out of 51 cases of trigeminal neuralgia 27 were males and 24 were females. The neurovascular contact was seen in 41 (80.4%) cases and 17 (28.3%) controls. Change in caliber of trigeminal nerve was seen in 27 (52.9%) cases and only in 01 (1.66%) control. Arterial imprint on nerve was seen in 26 (50.9%) cases and 01 (1.66%) control. Distortion of the course of nerve was seen in 12 (23.5%) cases and 01 (1.66%) control. Superior cerebellar artery was commonest vessel seen in contact with nerve on affected side in 25 (61%) cases. Conclusion: Demonstrating neurovascular contact alone is not enough for diagnosis of conflict as it is also present in some asymptomatic individuals, therefore it is important to identify thinning of nerve, arterial imprint or grooving and distortion in course of nerve, as these are more reliable signs of a conflict between the vessel and the nerve, and these cases are best treated surgically by Micro Vascular Decompression (MVD).

A Combination of 3D TOF MRA and FIESTA Predicts Surgery-Needed Primary Trigeminal Neuralgia and Specific Offending Vessels

“…However, these patients may have the tendency to develop into classical paroxysmal pain, which indicates the importance of followup for asymptomatic patients with observed NVC. To answer the question that when neurovascular contact turns into a conflict, several studies have reported the significant TN predictors, including thinning nerve, distortion of the course of nerve, and nerve indentation or displacement [4,24].…”

Surgical and Clinical Outcomes of Microvascular Decompression: A Comparative Study between Young and Elderly Patients

“…For each patient, the following data were gathered: Clinical pre-operative data: age, sex, affected side, TN type, pain duration (years), Barrow Neurological Institute Pain Intensity (BNI) score [ 15 ], previous surgery; Intraoperative data: craniotomy size; use of neuronavigation during surgery [ 16 ]; surgical duration and mastoid opening. Intraoperative conflict was classified as: “contact only” when the offending artery was in contact with the nerve root but without any visible indentation and “distortion and/or indentation” when there was a distortion and/or an indentation of the nerve root caused by the offending artery [ 17 , 18 ]; Post-operative/follow-up data: acute pain relief (APR) (pain-free at hospital discharge); cerebrospinal fluid (CSF) leak after surgery and complication other than CSF leak; length of stay; pain-free survival determined at the most recent follow-up visit, need for re-operation and BNI at follow-up. …”

“…Intraoperative data: craniotomy size; use of neuronavigation during surgery [ 16 ]; surgical duration and mastoid opening. Intraoperative conflict was classified as: “contact only” when the offending artery was in contact with the nerve root but without any visible indentation and “distortion and/or indentation” when there was a distortion and/or an indentation of the nerve root caused by the offending artery [ 17 , 18 ];…”

Neurovascular Compression in the Anterior Visual Pathway: A Case Series

“…11 It is important to radiologically identify nerve thinning, arterial imprint or grooving, or distortion of the course of the nerve, which may lead to the symptomatic presentations. 11 Arterial imprint or grooving is focal thinning of the nerve at the neurovascular compression site. Intraoperative histopathological study in patients with trigeminal neuralgia secondary to NVCS has shown demyelination and axonal loss.…”

“…In patients with trigeminal neuralgia who have similar pathomechanism resulting in compressive neuropathy, it has been noted that a neurovascular contact alone is not enough for diagnosis of NVCS. 11 It is important to radiologically identify nerve thinning, arterial imprint or grooving, or distortion of the course of the nerve, which may lead to the symptomatic presentations. 11 Arterial imprint or grooving is focal thinning of the nerve at the neurovascular compression site.…”