未經治療自發性消退的腦動靜脈畸形

Spontaneous Partial Regression of Cerebral Areteriovenous Malformations

腦部動靜脈畸形為一種動態性病灶。他的動脈供應和靜脈回流會隨著時間而有所改變。通常動靜脈畸形如果沒有治療，常常隨著時間而變大，但在很少數的病例可以見到動靜脈畸形未經治療而有自發性消退的情形。已經有許多的假說被用來解釋動靜脈畸形自行消退的原因：像是自發性出血後血流動力學的改變，腦部經手術的刺激，腦腫瘤的影響，高凝血病變，顱內動脈硬化和動脈瘤相關的血栓形成。臨床上大多數自發性消退的腦動靜脈畸形具有體積小，表淺性和單一靜脈回流的影像學特徵。60-70%的自發性消退腦動靜脈畸形在消退前至少會有一次顱內出血的臨床表現。我們報告一個自發性消退的腦動靜脈畸形病例，此病人在動靜脈畸形消退前並無任何顱內出血或相關的神經症狀表現。其自發性消退的原因依影像學判斷最可能是靜脈回流的栓塞引起。

Cerebral arteriovenous malformations (AVMs) are dynamic lesions. Their arterial supply and/or venous drainage may change over time. They usually increase in size with time, but in rare instances may spontaneously regress due to thrombosis. Several causes of regression have been postulated, for example, hemodynamic alterations due to spontaneous hemorrhage, surgery, the presence of a brain tumor, hypercoagulability, atherosclerosis, and thromboembolism from associated aneurysms. We present a case of spontaneous and asymptomatic partial occlusion of an AVM associated with thrombosis of the draining cortical vein. Possible mechanisms leading to the occlusion are discussed.