Large Vessel Occlusion in Acute Stroke

Study Questions:

Would incorporation of “cortical signs” such as aphasia and neglect, as compared to hemiparesis alone, increase the sensitivity of a prehospital tool for identifying large vessel occlusion (LVO) stroke patients?

Methods:

This was a retrospective analysis of 543 consecutive ischemic (n = 504) and hemorrhagic (n = 39) stroke patients admitted to a single center’s neurology department in 2015. Patients were included if they presented within 4.5 hours of last known normal. Sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) for cortical signs and hemiparesis were calculated.

Results:

Of the 543 patients, 181 had LVO. The sensitivity, specificity, PPV, and NPV for the different markers for LVO are as follows:

 

Sensitivity

Specificity

PPV

NPV

Hemiparesis only

0.85

0.53

0.47

0.87

Cortical sign(s) only

0.91

0.70

0.60

0.94

Cortical sign(s) and hemiparesis

0.79

0.82

0.68

0.88

Cortical sign(s) or hemiparesis

0.97

0.41

0.45

0.97

Conclusions:

Neuroanatomic considerations suggest that the presence of cortical signs such as aphasia and neglect may help predict the presence of an LVO. The results of this study suggest that the incorporation of cortical signs, as compared to hemiparesis alone, would increase the sensitivity of a prehospital tool to identify LVO patients. The results suggest that the highest sensitivity would be achieved if the prehospital tool includes cortical signs OR hemiparesis.

Perspective:

Not all medical centers are thrombectomy-capable. Identifying in the prehospital setting which stroke patients have LVO and thus should be diverted to a thrombectomy-capable center has important implications for EMS systems of care. Given that untreated LVO strokes are associated with high morbidity and mortality, a practical prehospital tool should sacrifice high specificity for high sensitivity and should sacrifice a high PPV for a high NPV. This study suggests that the evaluation and inclusion of cortical signs should be a standard feature of prehospital tools for identifying LVO.

Clinical Topics: Cardiac Surgery, Invasive Cardiovascular Angiography and Intervention, Prevention, Cardiac Surgery and Arrhythmias

Keywords: Aphasia, Coronary Occlusion, Intracranial Hemorrhages, Myocardial Ischemia, Neurology, Paresis, Secondary Prevention, Stroke, Thrombectomy, Vascular Diseases


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