両側大脳脚病変による"locked-in"syndromeの1剖検例

"LOCKED-IN" SYNDROME WITH BILATERAL MIDBRAIN INFARCTS:REPORT OF AN AUTOSPY

　抄録　両側大脳脚梗塞病変による"locked-in"syndromeの1例を報告した。症例は死亡時51歳の男性で頭部外傷後に記銘力障害や性格変化をきたし，その後"locked-in"syndromeを呈した。すなわち，痙性四肢麻痺と核上性球麻痺がみられ，眼球運動は保たれていた。左逆行性椎骨動脈造影で脳底動脈の描出が不良で，上小脳動脈と後下小脳動脈の吻合が認められた。病理学的には，大脳脚は両側性に帯状に軟化し，橋では正中部と腹側正中部に梗塞巣がみられたが，橋での病巣は錐体路をまきこんではいなかつた。また頭部外傷による左前頭葉眼窩回の脳挫傷とこれによる左前頭葉白質の虚血性梗塞がみられ，その他，延髄右外側部や左中小脳脚などに梗塞巣がみられた。左前頭葉眼窩回病巣による左視床内側核の逆行性変性や，左中小脳脚病巣によるPurkinje細胞や橋核の脱落などの副次的所見がみられた。中脳，橋，延髄の脳幹被蓋は保たれていて，これは上小脳動脈と後下小脳動脈の吻合によるものと考えた。本例の"locked-in"syndromeの成因は両側大脳脚の梗塞病変に求められ，脳底動脈の閉塞部位との関連を考察した。

A case of "Locked-in" syndrome with bilateral midbrain infarcts was reported.

A 51-year-old man had a memory disturbance and a change of his personality after head trauma, and then became rapidly "Locked-in" state. He was quadriplegic and bulbar paralytic, but ocular movements were preserved. Left VAG showed the narrowing of the basilar artery and there was a striking anastomosis between the SCA and PICA.

Neuropathological findings were as the fol-lowing ;

1) The lateral two third of bilateral cerebral peduncles were extensively infarcted.

2) There were contusion of the left frontal orbital surface and the ischemic infarction of the left frontal white matter.

3) Two small infarcted lesions were found in the ventral puns without involving the pyramidal tracts.

4) Additional findings were retrograde degene-ration of the medial nucleus of the left thalamus from the left frontal orbital lesion, and were loss of the Purkinje cells and neurons of pontine nucleus from the infarction of the middle cerebel-lar peduncle.

Tegmentum of the midbrain, pons and medulla were preserved, which was considered to be due to the anastomosis of the SCA and PICA.

Bilateral midbrain infarcts are responsible lesions in this case and it seems that "Locked-in" state is not synonymous with the "Ventral pon-tine syndrome".