罕見椎基底動脈分支畸形－左側單一下小腦動脈

A Rare Branch Anomaly of Vertebral-Basilar Artery-Only One Left Inferior Cerebellar Artery

陳建志(Jiann-Jy Chen) ； 劉智仰(Chih-Yang Liu) ； 孫盛義(Sheng-Yih Sun) ； 蔡芳生(Fang-Sheng Tsai) ； 陳登郎(Dem-Lion Chen)

《台灣耳鼻喉頭頸外科雜誌》 45卷1期 (2010/02) Pp. 25-30

https://doi.org/10.6286/2010.45.1.25

摘要

基底動脈的主要分支為後大腦動脈、上小腦動脈與前下小腦動脈，上小腦動脈、前下小腦動脈與源自於椎動脈之後下小腦動脈供應整個小腦與部分腦幹的血液循環，它們在末梢會有吻合。一66歲男性，持續兩側耳鳴、反覆眩暈及頭痛發作已半年，搖頭測試與向左之推頭測試為陽性，純音聽力檢查顯示兩側高頻性的聽力障礙，聽性腦幹電波反應檢查顯示左側I與III波潛值及潛值差較右側延長，向左之視運動性眼振及兩側視運動性後眼振呈現異常，左側前庭誘發肌性電位檢查之P13與N23波潛值較右側延長。診斷為偏頭痛性眩暈，可能造成左側腦幹與左側前庭的功能障礙。最後，飛行時間效應血管磁振造影顯示後方威利氏環不完整與椎基底動脈分支畸形―左側前下小腦動脈與後下小腦動脈被單單一條源自於基底動脈之「下小腦動脈」所取代。該椎基底動脈之分支畸形相當罕見，文獻中尚無人提及，尚不明瞭其臨床意義，無法證實與本個案病症間的關聯，可能在偏頭痛發作時，增加偏頭痛性眩暈發生的機會。

關鍵字

偏頭痛性眩暈 ； 椎基底動脈 ； 後顱窩循環 ； 下小腦動脈

並列摘要

The main branches of basilar artery (BA) are posterior cerebral arteries, superior cerebellar arteries (SCA), and anterior inferior cerebellar arteries (AICA). SCA, AICA and posterior inferior cerebellar arteries (PICA) from vertebral arteries (VA) supply the whole cerebellum and partial brainstem, and they are peripherally anastomosed. A 66-year-old male presented with persistent bilateral tinnitus, and frequent episodes of vertigo and headache for half a year. Head shaking test and left-rotated head thrust test were positive. Pure tone audiometry showed bilateral high tone sensori-neural hearing loss. Auditory brainstem-evoked response showed the latency and inter-latency of I and III wave were more prolonged in the left than the right. Left-directed optokinetic nystagmus test and bilateral optokinetic after nystagmus test showed abnormal waves. Vestibular evoked myogenic potential showed more prolonged latency of P13 and N23 wave in the left than the right. Therefore, migrainous vertigo was diagnosed, and impairment of left brainstem and left vestibule were highly suspected. Finally, time-offlight magnetic resonance angiogram showed a defect of posterior circle of Willis and a branch anomaly of vertebral-basilar artery (VBA)-only one left inferior cerebellar artery, instead of left AICA and left PICA, originated from BA. Because the branch anomaly of VBA is rare and limited in the literature, we reported the case. Though it is yet of unknown significance, and did not explicate any relation with his symptoms, we suggest it encourages migrainous vertigo during migraine attack.

並列關鍵字

migrainous vertigo ； vertebral-basilar artery ； posterior circulation ； inferior cerebellar artery