Trigeminal Neuralgia Attributable to Intraneural Trigeminocerebellar Artery: Case Report and Review of the Literature.

Background: The trigeminocerebellar artery (TCA) is a branch of the basilar artery supplying both the trigeminal nerve root and the cerebellar hemisphere. Despite its proximity to the trigeminal nerve, only a few cases of trigeminal neuralgia (TN) caused by TCA compression of the trigeminal nerve have been reported. Moreover, TN caused by blood vessel penetration of the trigeminal nerve is very rare.

Methods: We present a case of an 82-year-old female patient with typical episodes of TN. The radiologic studies showed that the offending artery was a unique branch of the basilar artery originating at a higher level than that of the usual anterior inferior cerebellar artery. During microvascular decompression surgery we were able to identify the offending vessel supplying the trigeminal nerve root and traveling between the sensory and motor root of the trigeminal nerve as an intraneural TCA. To shift the TCA away from the root entry zone, we dissected the epineurium of trigeminal nerve parallel to its axis and anchored the proximal portion of the TCA to the petrous dura. The patient's pain was completely gone immediately after the operation, with no neurologic deficits reported.

Conclusions: The TCA is a potential offending vessel in TN because of trigeminal nerve compression, and the longitudinal dissection of the trigeminal nerve to make space between the vessel and the nerve roots may be an effective procedure to relieve TN caused by pressing intraneural vessels.