Diagnostic accuracy of clinical tools for assessment of acute stroke: a systematic review

Abstract

Introduction Recanalisation therapy in acute ischaemic stroke is highly time-sensitive, and requires early identification of eligible patients to ensure better outcomes. Thus, a number of clinical assessment tools have been developed and this review examines their diagnostic capabilities. Methods Diagnostic performance of currently available clinical tools for identification of acute ischaemic and haemorrhagic strokes and stroke mimicking conditions was reviewed. A systematic search of the literature published in 2015-2018 was conducted using PubMed, EMBASE, Scopus and The Cochrane Library. Prehospital and in-hospital studies with a minimum sample size of 300 patients reporting diagnostic accuracy were selected. Results Twenty-five articles were included. Cortical signs (gaze deviation, aphasia and neglect) were shown to be significant indicators of large vessel occlusion (LVO). Sensitivity values for selecting subjects with LVO ranged from 23% to 99% whereas specificity was 24% to 97%. Clinical tools, such as FAST-ED, NIHSS, and RACE incorporating cortical signs as well as motor dysfunction demonstrated the best diagnostic accuracy. Tools for identification of stroke mimics showed sensitivity varying from 44% to 91%, and specificity of 27% to 98% with the best diagnostic performance demonstrated by FABS (90% sensitivity, 91% specificity). Hypertension and younger age predicted intracerebral haemorrhage whereas history of atrial fibrillation and diabetes were associated with ischaemia. There was a variation in approach used to establish the definitive diagnosis. Blinding of the index test assessment was not specified in about 50% of included studies. Conclusions A wide range of clinical assessment tools for selecting subjects with acute stroke has been developed in recent years. Assessment of both cortical and motor function using RACE, FAST-ED and NIHSS showed the best diagnostic accuracy values for selecting subjects with LVO. There were limited data on clinical tools that can be used to differentiate between acute ischaemia and haemorrhage. Diagnostic accuracy appeared to be modest for distinguishing between acute stroke and stroke mimics with optimal diagnostic performance demonstrated by the FABS tool. Further prehospital research is required to improve the diagnostic utility of clinical assessments with possible application of a two-step clinical assessment or involvement of simple brain imaging, such as transcranial ultrasonography.

Stroke mimics: incidence, aetiology, clinical features and treatment

“…In a more recent systemic review of 25 studies published between 2015 and 2018, the presence of cortical signs (gaze deviation and aphasia and neglect) was most helpful in the diagnosis of large vessel occlusion (LVO). The range of sensitivity (23-99%) and specificity (24-97%) for LVO, unfortunately, remains wide and require improvements [39]. In a study from our centre, the pre-hospital blood pressure was significantly higher in acute stroke patients compared to mimics [40].…”

Value of high-density sign on CT images after mechanical thrombectomy for large vessel occlusion in predicting hemorrhage and unfavorable outcome

“…There are, however, diagnostic difficulties to accurately predict which patient will suffer from devastating consequences. 4–7…”

Accuracy of Field Assessment Stroke Triage for Emergency Destination for Diagnosis of Acute Ischemic Stroke Patients

“…However, NIHSS is complex and timeconsuming (8). Some existing simplified stroke screens, such as Melbourne Ambulance Stroke Screen, the Face Arm Speech Test (FAST), Cincinnati Prehospital Stroke Severity Scale (CPSSS) and its modification and Recognition of Stroke in the Emergency Room (ROSIER) were designed to detect strokes (1,8,9). The accuracy of these clinical scales varies between 0.75 and 0.80 and differs slightly from each other (8)(9)(10).…”