Presents as sudden onset of severe, unilateral, paroxysmal pain in one or more of the distributions of the trigeminal nerve.
Vascular compression is most common cause, superior cerebellar artery being the most common culprit.
Proximal centrally myelinated portion of the nerve is more susceptibility to compression as it is thinner as compared to the relatively thicker distal peripheral myelin sheath. Distal compression may not be clinically relevant.
3D CISS/SSFP sequence is the sequence of choice.
What surgeons want to know:
Compressive vessel is an artery or vein.
Name of the vessel or vessels.
Distal or proximal half of the cisternal segment of the trigeminal nerve is compressed.
Treatment : Surgical decompression by transposing the vessel from the nerve and separating it by using non-absorbable material, most frequently Teflon pledgets. This can be seen a small hypointensity on post operative images.