Diagnostic value of transcranial ultrasonography for selecting subjects with large vessel occlusion: a systematic review

Abstract

IntroductionA number of pre-hospital clinical assessment tools have been developed to triage subjects with acute stroke due to large vessel occlusion (LVO) to a specialised endovascular centre, but their false negative rates remain high leading to inappropriate and costly emergency transfers. Transcranial ultrasonography may represent a valuable pre-hospital tool for selecting patients with LVO who could benefit from rapid transfer to a dedicated centre.MethodsDiagnostic accuracy of transcranial ultrasonography in acute stroke was subjected to systematic review. Medline, Embase, PubMed, Scopus, and The Cochrane Library were searched. Published articles reporting diagnostic accuracy of transcranial ultrasonography in comparison to a reference imaging method were selected. Studies reporting estimates of diagnostic accuracy were included in the meta-analysis.ResultsTwenty-seven published articles were selected for the systematic review. Transcranial Doppler findings, such as absent or diminished blood flow signal in a major cerebral artery and asymmetry index ≥ 21% were shown to be suggestive of LVO. It demonstrated sensitivity ranging from 68 to 100% and specificity of 78–99% for detecting acute steno-occlusive lesions. Area under the receiver operating characteristics curve was 0.91. Transcranial ultrasonography can also detect haemorrhagic foci, however, its application is largely restricted by lesion location.ConclusionsTranscranial ultrasonography might potentially be used for the selection of subjects with acute LVO, to help streamline patient care and allow direct transfer to specialised endovascular centres. It can also assist in detecting haemorrhagic lesions in some cases, however, its applicability here is largely restricted. Additional research should optimize the scanning technique. Further work is required to demonstrate whether this diagnostic approach, possibly combined with clinical assessment, could be used at the pre-hospital stage to justify direct transfer to a regional thrombectomy centre in suitable cases.

Aplicaciones clínicas de Doppler Transcraneal en Neurología y Cuidados Neuro críticos.

“…En enfermedad cerebrovascular oclusiva o estenónica se describe el uso de DTC para detectar cambios hemodinámicos asociados a variación del calibre de los vasos intracraneales del polígono de Willis. En enfermedad vascular oclusiva para la arteria cerebral media se describe sensibilidad de 85-95 % y sensibilidad de 90-98 % y para arterias carótidas internas, arterias vertebrales y arteria basilar sensibilidad de 55-81 % y especificidad de 96 % 9 .…”

“…En HSA, el uso de DTC tiene como principal aplicación la identificación de vasoespasmo en los segmentos basales de las arterias intracraneales; complicación que puede desarrollarse las primeras dos semanas 16 , teniendo el estudio doppler para su detección, sensibilidad para la arteria cerebral media de 39-94 % y especificidad de 70-100 %, para la arteria cerebral anterior sensibilidad de 13-71 % y especificidad de 65-100 %, para arterias cerebrales posteriores sensibilidad de 48-60 % y especificidad de 78-87 %, para arterias vertebrales sensibilidad de 44-100 % y especificidad de 82-88 % y para arteria basilar sensibilidad de 77-100 % y especificidad de 42-79 % 9 . En HSA los hallazgos de las velocidades de flujo de las arterias detectadas por DTC se correlaciona con el grado clínico y localización radiológica por neuroimagen del vasoespasmo 16 .…”

“…El doppler transcraneal permite identificar en niños con edades entre 4-20 años el riesgo de ictus, determinando las velocidades medias, determinándose la relación de aumento de riesgo entre mayor es la velocidad. Se ha descrito una sensibilidad de 86 % y especificidad del 91 % 9 .…”

“…Se ha descrito una sensibilidad de 70-100 % y especificidad de más de 95 % 9 . La causa más frecuente es el embolismo paradójico a través de un foramen oval persistente, que es causa de evento cerebrovascular en adultos jóvenes 20 .…”

The use of transcranial ultrasound and clinical assessment to diagnose ischaemic stroke due to large vessel occlusion in remote and rural areas

“…Portable transcranial ultrasound has emerged as a potential method for rapidly assessing the intracranial circulation [10,11] demonstrating sensitivity ranging from 68% to 100% and specificity 78% to 99% for detecting acute vessel occlusion and stenosis [12]. It can detect haemorrhagic lesions in the deep brain structures [13], and a shift of intracranial midline structures � 0.25cm can be used as an indicator of a large brain haemorrhage [14].…”