Trigeminal nerve: MRI anatomy and case presentation of trigeminal neuralgia due to arterial compression.

Trigeminal neuralgia (TN), also known as tic douloureux is a chronic neuropathic pain disorder characterized by sporadic episodes of extreme, sudden burning or shock-like face pain that last from a few seconds to 2 minutes. Trigeminal neuralgia has a reported incidence of 5.9/100,000 women and 3.4/100,000 men in USA. The exact pathophysiology is still unclear, but demyelization leading to abnormal discharge in fibers of the trigeminal nerve is a probable cause. In the majority of cases, no structural lesion is detected but in almost 15% of patients medical imaging methods like MRI, CT or angiography can identify a vein or artery that compresses the nerve which results in focal demyelization. The authors present a case of trigeminal neuralgia investigated by MRI, which identified a vascular compression of the nerve 9 mm after emerging the pons by the superior cerebellar artery (SCA) and one of its branches. The authors also realize a review of the MRI anatomy of the trigeminal nerve.