Telestroke Accurately Distinguishes Ischemic Stroke From Stroke Mimics

Jason Poon, MD

Data from a recent study suggest that telestroke consultations can accurately differentiate between acute ischemic stroke (AIS) and stroke mimics.

These findings were presented at the 2021 American Academy of Neurology (AAN) Annual Meeting, April 17-22, by Jason Poon, MD, neurology department, University of Utah. Poon and colleagues sought to investigate the accuracy of stroke versus stroke mimics diagnoses made while evaluating patients via telestroke, as stroke mimics account for up to 50% of telestroke consults, yet it is unknown if telestroke can accurately differentiate between stroke and mimics.

Intravenous tissue plasminogen activator (IV-tPA) is currently underutilized for AIS in the US, while telestroke has been demonstrated to increase accuracy of AIS diagnosis, decrease time to delivery of iv-tPA, and increase the use of IV-tPA for AIS, according to Poon’s presentation.

“From the standpoint of the patient, [telestroke] gives them access to a vascular neurologist in the scenario of stroke consult. But from a management standpoint, it has been shown to improve adherence to stroke protocols, utilization of IV-tPA, and more appropriate and quicker referrals to higher centers that allow for mechanical thrombectomy,” Poon told NeurologyLive.

WATCH NOW: Applications of Telestroke and Teleneurology: Jason Poon, MD

Poon and colleagues conducted a retrospective review of 476 telestroke cases with the University of Utah as the “hub” and 27 outside facilities as the “spokes.” Of those cases, 71 were excluded for lack of discharge diagnosis, leaving 405 cases for analysis. Altogether, the patients involved in the telestroke consults had an average age of 66.4 years (interquartile range [IQR], 55-79) and 218 (53.8%) were women. Mean National Institutes of Health Stroke Scale score was 5.13 (IQR, 1-6), tPA was administered in 103 (45%) patients, and 85 were transferred to hub hospitals.

Out of the cases reviewed, 225 were diagnosed with AIS over telestroke; 10% were later diagnosed with stroke mimics. Stroke mimics, overall, were diagnosed in 180 patients; 27 (15%) of those were diagnosed with AIS by discharge. Out of the stroke mimics diagnosed, 29 were diagnosed with a migraine-related mimic and this diagnosis was 79.5% accurate. Nineteen patients were diagnosed with a seizure; this diagnosis was 70.8% accurate. Twenty-two were diagnosed with conversion/anxiety and this diagnosis was 86.4% accurate.

Altogether, AIS diagnosis over telestroke had a high diagnostic agreement (89.8%) with a kappa of 0.75 for stroke and mimics. Telestroke mimic diagnosis had a positive predictive value (PPV) of 85% and a negative predictive value (NPV) of 90%, while telestroke diagnosis of AIS had a PPV of 90% and an NPV of 85%.

“The purpose of this study was to try to understand what the accuracy for telestroke was in making the diagnosis of stroke mimic as well as stroke. And the ultimate end goal of that was to be able to say that teleneurology had appropriate accuracy for the management of patients, whether it be in the inpatient or outpatient setting,” Poon said to NeurologyLive. 

Additionally, Poon noted in his presentation that the low mimic rate and high tPA use may reflect bias from the spoke sites to only seek telestroke consult for patients that likely require tPA. He also called for improved documentation from hub and spoke sites to advance understanding of the telestroke system.

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REFERENCE

Poon JT, Hoversten K, Tkach A, et al. Telestroke consultation can accurately diagnose ischemic stroke mimics. Presented at 2021 American Academy of Neurology Annual Meeting; April 17-22. Abstract P5 164