英国学者的一项前瞻性基于人群的研究发现：在患有明确的椎基底动脉卒中的患者中，卒中发生前常见单独的短暂性脑干症状，但是大多数症状不符合TIA的传统定义。单独的短暂性脑干症状的预后还有待更多研究来证实。该论文于近日在线发表于《柳叶刀·神经学》杂志。

　　单独的短暂性脑干症状如单独的眩晕，构音困难，复视等并没有一贯地划分为短暂性脑缺血发作（TIAs）且预后方面的数具有限。如果这些短暂的神经发作（TNAs）是由于椎基底动脉缺血，那么这些症状在后循环卒中发作前的几天或几周期间应该很常见。

　　该研究旨在评价椎基底动脉缺血性卒中发作前TNAs的发作频率。

　　该项在英国牛津夏州进行的前瞻性基于人群的发生率研究中，研究人员研究了缺血性卒中发生前90天期间的所有潜在缺血性事件，并对比了椎基底动脉缺血性卒中和颈动脉卒中前TNA的发生率。TNAs的划分在不同区域有所不同：在椎基底动脉区域为脑干症状如单独的眩晕，眩晕伴非局灶性症状，单独的复视，短暂的全身虚弱和双眼视觉障碍；在颈动脉区域为非典型一过性黑朦和肢体抖动；在不确定区域为单独的言语不清，变异性偏头痛，短暂的意识模糊和单侧麻木综合症。

　　结果显示，在1141名缺血性卒中患者中，有1034名（91%）患者发生在可分类的血管分布区，其中275人椎基底动脉卒中和759人颈动脉卒中。与颈动脉卒中前相比，椎基底动脉卒中前单独的脑干TNAs更频繁（p<0·0001），尤其是卒中前2天。在椎基底动脉卒中前的所有59例TNAs中，只有5例达到了美国国家神经疾病和卒中研究所（NINDS）的TIA标准。其他54例为单独的眩晕，非NINDS双眼视觉障碍，眩晕伴有其他非局灶性症状，单独的言语不清，单侧肢体麻木或复视，和非局灶性事件。伴有单独的脑干TNAs的患者只有22%在卒中发生前就医，这些病例中只有一例患者的医生怀疑是血管原因引起的。

　　因此，通过该研究，作者认为在明确的椎基底动脉卒中患者中，卒中之前有短暂性孤立性脑干症状是常见的，并且大多数症状未符合TIA的传统定义。短暂性孤立性脑干症状的发生后需警惕椎基底动脉卒中。

　　BACKGROUND: Transient isolated brainstem symptoms (eg, isolated vertigo, dysarthria, diplopia) are not consistently classified as transient ischaemic attacks (TIAs) and data for prognosis are limited. If some of these transient neurological attacks (TNAs) are due to vertebrobasilar ischaemia, then they should be common during the days and weeks preceding posterior circulation strokes. We aimed to assess the frequency of TNAs before vertebrobasilar ischaemic stroke. METHODS: We studied all potential ischaemic events during the 90 days preceding an ischaemic stroke in patients ascertained within a prospective, population-based incidence study in Oxfordshire, UK (Oxford Vascular Study; 2002-2010) and compared rates of TNA preceding vertebrobasilar stroke versus carotid stroke. We classified the brainstem symptoms isolated vertigo, vertigo with non-focal symptoms, isolated double vision, transient generalised weakness, and binocular visual disturbance as TNAs in the vertebrobasilar territory; atypical amaurosis fugax and limb-shaking as TNAs in the carotid territory; and isolated slurred speech, migraine variants, transient confusion, and hemisensory tingling symptoms as TNAs in uncertain territory. FINDINGS: Of the 1141 patients with ischaemic stroke, vascular territory was categorisable in 1034 (91%) cases, with 275 vertebrobasilar strokes and 759 carotid strokes. Isolated brainstem TNAs were more frequent before a vertebrobasilar stroke (45 of 275 events) than before a carotid stroke (10 of 759; OR 14·7, 95% CI 7·3-29·5, p<0·0001), particularly during the preceding 2 days (22 of 252 before a vertebrobasilar stroke vs two of 751 before a carotid stroke, OR 35·8, 8·4-153·5, p<0·0001). Of all 59 TNAs preceding (median 4 days, IQR 1-30) vertebrobasilar stroke, only five (8%) fulfilled the National Institute of Neurological Disorders and Stroke (NINDS) criteria for TIA. The other 54 cases were isolated vertigo (n=23), non-NINDS binocular visual disturbance (n=9), vertigo with other non-focal symptoms (n=10), isolated slurred speech, hemisensory tingling, or diplopia (n=8), and non-focal events (n=4). Only 10 (22%) of the 45 patients with isolated brainstem TNAs sought medical attention before the stroke and a vascular cause was suspected by their physician in only one of these cases. INTERPRETATION: In patients with definite vertebrobasilar stroke, preceding transient isolated brainstem symptoms are common, but most symptoms do not satisfy traditional definitions of TIA. More studies of the prognosis of transient isolated brainstem symptoms are required. FUNDING: Wellcome Trust, UK Medical Research Council, Dunhill Medical Trust, Stroke Association, National Institute for Health Research (NIHR), Thames Valley Primary Care Research Partnership, and the NIHR Biomedical Research Centre, Oxford.