英國學者的一項前瞻性基于人群的研究發現：在患有明確的椎基底動脈卒中的患者中，卒中發生前常見單獨的短暫性腦干癥狀，但是大多數癥狀不符合TIA的傳統定義。單獨的短暫性腦干癥狀的預后還有待更多研究來證實。該論文于近日在線發表于《柳葉刀·神經學》雜志。
單獨的短暫性腦干癥狀如單獨的眩暈，構音困難，復視等并沒有一貫地劃分為短暫性腦缺血發作（TIAs）且預后方面的數具有限。如果這些短暫的神經發作（TNAs）是由于椎基底動脈缺血，那么這些癥狀在后循環卒中發作前的幾天或幾周期間應該很常見。
該研究旨在評價椎基底動脈缺血性卒中發作前TNAs的發作頻率。
該項在英國牛津夏州進行的前瞻性基于人群的發生率研究中，研究人員研究了缺血性卒中發生前90天期間的所有潛在缺血性事件，并對比了椎基底動脈缺血性卒中和頸動脈卒中前TNA的發生率。TNAs的劃分在不同區域有所不同：在椎基底動脈區域為腦干癥狀如單獨的眩暈，眩暈伴非局灶性癥狀，單獨的復視，短暫的全身虛弱和雙眼視覺障礙；在頸動脈區域為非典型一過性黑朦和肢體抖動；在不確定區域為單獨的言語不清，變異性偏頭痛，短暫的意識模糊和單側麻木綜合癥。
結果顯示，在1141名缺血性卒中患者中，有1034名（91%）患者發生在可分類的血管分布區，其中275人椎基底動脈卒中和759人頸動脈卒中。與頸動脈卒中前相比，椎基底動脈卒中前單獨的腦干TNAs更頻繁（p<0·0001），尤其是卒中前2天。在椎基底動脈卒中前的所有59例TNAs中，只有5例達到了美國國家神經疾病和卒中研究所（NINDS）的TIA標準。其他54例為單獨的眩暈，非NINDS雙眼視覺障礙，眩暈伴有其他非局灶性癥狀，單獨的言語不清，單側肢體麻木或復視，和非局灶性事件。伴有單獨的腦干TNAs的患者只有22%在卒中發生前就醫，這些病例中只有一例患者的醫生懷疑是血管原因引起的。
因此，通過該研究，作者認為在明確的椎基底動脈卒中患者中，卒中之前有短暫性孤立性腦干癥狀是常見的，并且大多數癥狀未符合TIA的傳統定義。短暫性孤立性腦干癥狀的發生后需警惕椎基底動脈卒中。
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.