Carotid-basilar Anastomosis—Arteria Hypoglossica Primitiva

CAROTID-BASILAR ANASTOMOSIS:ARTERIA HYPOGLOSSICA PRIMITIVA

I．はじめに

　脳血管写の普及に伴つて，従来剖検でまれに認められるにすぎなかつた脳血管系の発生異常が生体においてもあいついで報告されるようになつた。

　胎生初期において，内頸動脈系と脳底動脈系との間にはいくつかの吻合路がある。通常これらは個体発生の途上次第に吸収されるが，まれにこれが完全なかたちで，または部分的に，遺残することがある。この種のいわゆるcarotid-basilar anastomosisとしては，従来prirnitive trigeminal artery, primitive acoustic （otic） artery, primi—tive hypoglossal arteryの3種が記載されている。

A 21-year-old lady was involved in a traffic accident but not rendered unconscious. She experienced a syn-copal attack associated with headache and nausea 7 weeks after the accident.

On neurologic examination 10 weeks after the ac-cident, hyperreflexia and diminished sensation to touch and pain were noted on the right side.

Left carotid arteriography, performed to exclude a chronic subdural hematoma, incidentally disclosed a persistent primitive hypoglossal artery. Right carotid arteriogram were normal. No hematomas were dis-closed on either side. Vertebral arteriographies were not attempted.

Available literature was reviewed and the embryo-logical and clinical aspects of the carotid-basilar anas-tomosis were discussed.

Causal relations between the persistence of the hypo-glossal artery and syncopal attack in this particular case remains unsolved.