Trigeminal Neuralgia-MRA

An adult with left trigeminal neuralgia on MRA shows a tortuous enlarged vascular loop of anterior inferior cerebellar artery pressing upon ipsilateral trigeminal nerve. This MRA was done by 3 Tesla MR scanner. Case submitted by Dr MGK Murthy, Mr Hariom, Mr Sahadev

 

Teaching Points :

• Trigeminal neuralgia (Tic Douloureux) is by definition intermitant shooting pain lasting from few seconds to less than 2 minutes, along the distribution of the trigeminal nerve.

• Commonest cause is an enlarged looping artery / vein pressing upon the nerve, others being multiple sclerosis / neoplasms / other space occupying lesions in  the vicinity.

• MRI along with MRA is considered as an ideal modality for delineation of the vessels.

• Anterior inferior cerebellar artery, a branch of the same, vertebral artery, superior cerebellar arteries are usually responsible for this syndrome.

• Commonest area of the contact is root entry zone of preganglionic segment  of the trigeminal nerve.

• Slow flow / Thrombous could occasionally be demonstrated.

• Coronal projection shows AICA vessels leading to the nerve with superior  cerebellar vessel in the cranial aspect.