To describe the rare association of trigeminal neuralgia (TGN) with a brain arteriovenous malformation (bAVM) of the posterior fossa.

This is a report of three patients presenting with TGN due to vascular compression by a bAVM of the posterior fossa, with emphasis on clinical presentation, diagnostic imaging, management and follow-up. Magnetic resonance imaging (MRI) was performed with sequences in thin slices in the same section plane using a 3D time of flight (TOF) and axial T2-weighted driven equilibrium (DRIVE) of the posterior fossa.

No bleeding episodes were documented in the three patients. MRI and digital subtraction angiography (DSA) showed a posterior fossa bAVM with a nidus surrounding the trigeminal nerve, fed by arteries from the carotid and vertebrobasilar systems. Within a few days, medical treatment effectively alleviated the symptoms, with no more pain during follow-ups at 6, 10 and 18months. No invasive treatment was performed because the bAVMs were considered to have a low risk of bleeding.

TGN related to a bAVM can mimic classical TGN. MRI and DSA are the imaging methods of choice. Medical treatment remains the first line of therapy, but if that fails, multimodal invasive treatment may be an alternative for pain relief.