A cross-sectional feasibility study of neurovascular ultrasound in Malawian adults with acute stroke-like syndrome

BackgroundIn sub-Saharan Africa, there is a dearth of epidemiologic data on the burden of cerebral atherosclerosis. This is explained by the limited availability and the high cost of standard vascular imaging techniques. Neurovascular ultrasound is portable, cheaper and non-invasive and could, therefore, represent a reasonable alternative to fill this knowledge gap. We explored the feasibility of neurovascular ultrasound in Malawian adults with acute stroke-like syndrome to inform the design of future large stroke studies comparing its diagnostic performance to that of gold standard vascular imaging techniques in sub-Saharan Africa.MethodsWe enrolled consecutive patients diagnosed with acute stroke-like syndrome based on the World Health Organization definition. Clinical and demographic data were recorded, and a comprehensive neurovascular ultrasound was performed. Fisher’s exact and Kruskal-Wallis tests were used to study the relationship between atherosclerosis and potential risk factors.ResultsSixty-six patients were enrolled (mean age: 58.7 years). The frequency of extracranial atherosclerosis was 39.4% (n = 26, 95% CI: 28.6–52.2). There were 12 patients with abnormal carotid intima media thickness (18.2%, 95% CI: 9.8–29.6) and 14 patients with a carotid plaque (21.2%, 95% CI: 12.1–33.0). The frequency of intracranial atherosclerosis was 19.2% (95%CI: 6.6–39.4) in 26 patients with successful transcranial insonation. Hypertension (80.8 versus 52.5%, p = 0.03) and hypercholesterolemia (11.5 versus 0.0%, p = 0.05) were more prevalent in patients with extracranial atherosclerosis.ConclusionsThis study demonstrates the feasibility of neurovascular ultrasound to assess cervical arteries in adults with stroke-like syndrome in sub-Saharan Africa. There is a high rate of transcranial insonation failure in this setting, highlighting the need for echocontrast agents.

**背景**：在撒哈拉以南非洲地区，脑动脉粥样硬化疾病负担的流行病学数据极为匮乏。这一现状源于标准血管成像技术可及性有限且成本高昂。神经血管超声（neurovascular ultrasound）具备便携、廉价且无创的优势，或可作为填补这一认知空白的合理替代方案。本研究旨在探索针对马拉维成年急性类卒中综合征患者开展神经血管超声检查的可行性，为未来在撒哈拉以南非洲地区开展大规模卒中研究提供依据——此类研究将对比神经血管超声与金标准血管成像技术的诊断效能。

**方法**：本研究纳入符合世界卫生组织（World Health Organization, WHO）定义的急性类卒中综合征连续就诊患者。收集患者的临床与人口学资料，并完成全面的神经血管超声检查。采用Fisher确切概率法与Kruskal-Wallis检验分析动脉粥样硬化与潜在危险因素之间的关联。

**结果**：本研究共纳入66例患者，平均年龄为58.7岁。颅外动脉粥样硬化的检出率为39.4%（n=26，95%置信区间[CI]：28.6~52.2）。其中12例患者存在颈动脉内膜中层厚度异常（18.2%，95%CI：9.8~29.6），14例患者存在颈动脉斑块（21.2%，95%CI：12.1~33.0）。在26例成功完成经颅超声探查的患者中，颅内动脉粥样硬化的检出率为19.2%（95%CI：6.6~39.4）。合并颅外动脉粥样硬化的患者中，高血压（80.8% vs 52.5%，P=0.03）与高胆固醇血症（11.5% vs 0.0%，P=0.05）的患病率更高。

**结论**：本研究证实，在撒哈拉以南非洲地区，针对类卒中综合征成年患者开展神经血管超声评估颈部动脉的方案具备可行性。该人群中经颅超声探查失败率较高，提示亟需使用超声造影剂。