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

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.

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.

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.

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).