静脈うっ滞により急速に脳幹症状を呈した頚髄硬膜動静脈瘻の1例

Cervical Spinal Dural Arteriovenous Fistula with Rapidly Progressive Brainstem Dysfunction Due to Venous Congestion:A Case Report

Ⅰ．はじめに

　脊髄硬膜動静脈瘻（spinal dural arteriovenous fistula：S-dAVF）は脊髄動静脈奇形の1型でAnson ＆ Spetzlerの分類でType Iに属する¹⁾．好発部位は胸腰髄であり，頚髄のS-dAVFは比較的稀である．静脈うっ滞性の脊髄症で発症することが圧倒的に多いが，通常症状は緩徐進行性である．今回われわれはうっ滞が脳幹まで及び，比較的急速に脳幹症状を呈した頚髄のS-dAVFを経験したので報告する．

　Spinal dural arteriovenous fistulas（S-dAVFs）are rare vascular malformations of the spine. We experienced a case that presented with rapidly progressive brainstem dysfunction due to venous congestion of cervical dAVFs.

　A 56-year-old man diagnosed with cervical dAVF four years prior presented with gait disturbance and abnormal thermal nociception on his right side. In addition to the high-intensity lesion from the lower pons to the medulla oblongata on T2-weighted magnetic resonance imaging, diffusion-weighted imaging demonstrated cerebral infarction of the left ventrolateral medulla oblongata. Left vertebral angiography revealed that a feeding artery supplied by the radicular artery at the C4 level formed a fistula with the dilated ascending anterior perimedullary vein. We made a diagnosis of venous congestion due to cervical dAVFs. Numbness on the left upper limb occurred five days after the first symptom. Subsequently, hemiparesis on the left upper limb and swallowing disturbance occurred two weeks after the first symptom. The patient underwent surgical ligation of the dilated abnormal vein, with gradual improvement of his symptoms.

　Myelopathy due to venous congestion of S-dAVFs usually progresses slowly for several years. However, this case report warns about the possibility that some cases of S-dAVF with rapidly exacerbated symptoms may require prompt therapy.