上方注視麻痺を初期徴候とした小脳梗塞によるtranstentorial upward herniationの1例

A Case of Transtentorial Upward Herniation due to Cerebellar Infarction Manifesting Upward Gaze Palsy as an Initial Sign

　一側小脳半球の広汎な梗塞により，transtentorial upward herniationを生じた症例を報告した。本例は上方注視麻痺出現の後，徐々に意識障害が出現し，MRIでtranstentorial upward herniationが確認されたため，緊急の後頭蓋窩減圧術を施行した。ヘルニアの初期徴候として上方注視麻痺を呈することは稀であるが，本ヘルニアの早期診断上注意すべき徴候と考えられた。

Transtentorial upward herniation is a rare com-plication of cerebellar infarction and its develop-ment indicates an emergency and necessity of poste-rior cranial fossa decompression.

A 63-year-old man with a history of myocardial infarction was admitted to the hospital complaining of sudden onset of vertigo and headache. Neuro-logical examination revealed marked upward gaze palsy, right blepharoptosis, facial weakness, hearing loss on the left side and ataxia of the left upper and lower extremities. A few hours later, he rapidly lost consciousness and MRI revealed massive infarction in the left cerebellar hemisphere and transtentorial upward herniation. Immediate surgical decompres-sion of the posterior cranial fossa was performed, thereafter patient gradually improved. This case suggests that upward gaze palsy is an important initial sign of transtentorial upward herniation with massive cerebellar infarction.