責任血管が三叉神経を貫通していた三叉神経痛の1例

Trigeminal Neuralgia with the Offending Artery Transfixing the Trigeminal Nerve : a case report

I．はじめに

　Dandy^2），Gardner^4），Jannetta^5）らにより神経血管減圧術が三叉神経痛の治療法として確立して以来，本法が広く普及してきた^1）．今回われわれは神経血管減圧術時に，責任血管の上小脳動脈（SCA）がroot entry zone（REZ）を圧迫した後に三叉神経を貫通する所見を認めた．このような症例は稀であり，手術手技に工夫を要したため若干の文献的考察を含め報告する．

We report a rare case of a patient manifesting trigeminal neuralgia with the offending artery transfixingthe trigeminal nerve. A 67-year-old woman was admitted with typical episodes of trigeminal neuralgia onthe right side. Magnetic resonace angiograms revealed the right superior cerebellar artery (SCA) com-pressing the nerve. Through a retromastoid suboccipital craniotomy on the right side, the right SCA wasfound to compress the root entry zone (REZ) and then penetrate the portio major of the trigeminal nerve.The nerve was dissected parallel to the axis, 7mm distally from the transfixing point to facilitate transposi-tion of the SCA. In addition to anchoring the distal portion of the SCA to the tentrium, a prosthesis wasinterposed between the proximal portion and the pons to secure the decompression. The pain was com-pletely relieved immediately after operation with no neurological deficit.

Procedures, such as the longitudinal rhizotomy employed in this case, must be carried out for microcom-pression, in response to individual anatomical variations in neurovascular structures.