Yang Hui, Zhong Shuisheng, Hu Yunxin, Bao Zeyan
Department of Neurology, Guangdong 999 Brain Hospital, Guangzhou, China.
Br J Neurosurg. 2023 Aug;37(4):650-652. doi: 10.1080/02688697.2018.1540763. Epub 2019 Jan 17.
Basilar invagination (BI) is a congenital or acquired craniovertebral junction (CVJ) anomaly with odontoid process superiorly migrating into the foramen magnum. Compression of neural structures is the most relevant complication of BI. However BI is also a rare cause of ischemic stroke. In this case we reported a 30-year-old female with BI who developed recurrent ischemic stroke in posterior circulation. Before the onset of ischemic stroke, she didn't present neck pain or clinical signs of lower cranial nerve dysfunction, brainstem compression or transient ischemic attack. At first she suffered from sudden onset of left-sided hemidysesthesia. Magnetic resonance imaging from a local hospital revealed an acute infarction in the right thalamus. Cerebral MR angiography was unremarkable at that time. The tip of the odontoid process had protruded into the foramen magnum and could be observed at the level of the lower medulla, but unfortunately it was ignored by the clinicians and the radiologists. She was given antiplatelet therapy and the sensory disturbance disappeared gradually. However she experienced a recurrence in the pontine and midbrain region 2 months later. At this time she was transferred to our hospital, and reconstructed computed tomography of cervical spine demonstrated basilar invagination, atlanto-axial dislocation, and atlanto-occipital assimilation. Computed tomographic angiography (CTA) revealed a dominant right vertebral artery (VA) and a redundant loop in its third segment. Dynamic cerebral angiogram demonstrated that the patient had a Bow Hunter's type phenomenon, with dynamic occlusion of the right dominant VA during contralateral head turn. This case highlighted the necessary of hemodynamic evaluation in asymptomatic basilar invagination.
基底凹陷症（BI）是一种先天性或后天性的颅颈交界区（CVJ）异常，齿状突向上移入枕骨大孔。神经结构受压是BI最相关的并发症。然而，BI也是缺血性卒中的罕见病因。在本病例中，我们报告了一名30岁患有BI的女性，其在后循环发生复发性缺血性卒中。在缺血性卒中发作前，她没有出现颈部疼痛或下颅神经功能障碍、脑干受压或短暂性脑缺血发作的临床体征。起初，她突然出现左侧半身感觉异常。当地医院的磁共振成像显示右侧丘脑急性梗死。当时的脑磁共振血管造影未见明显异常。齿状突尖端已突入枕骨大孔，可在延髓下部水平观察到，但不幸的是被临床医生和放射科医生忽视了。她接受了抗血小板治疗，感觉障碍逐渐消失。然而，2个月后她在脑桥和中脑区域复发。此时她被转到我院，颈椎重建计算机断层扫描显示基底凹陷症、寰枢椎脱位和寰枕融合。计算机断层血管造影（CTA）显示右侧椎动脉（VA）优势及第三段迂曲环。动态脑血管造影显示该患者存在Bow Hunter型现象，对侧转头时右侧优势VA动态闭塞。本病例强调了对无症状基底凹陷症进行血流动力学评估的必要性。
