13 Jul How Quickly and Accurately Can Ischemic Stroke Be Diagnosed and Treated with tPA?
MedicalResearch.com Interview with:
Perttu J. Lindsberg, MD, PhD
Professor of Neurology
Clinical Neurosciences and Molecular Neurology
Research Programs Unit, Biomedicum Helsinki
University of Helsinki Helsinki, Finland
MedicalResearch.com: What is the background for this study?
Response: The past 20 years in shaping the Helsinki model in stroke thrombolysis have proven that we can be very fast in examining the patient, completing the imaging and starting thrombolytic therapy. This is a university hospital center that receives roughly three stroke suspects per day for evaluation of recanalization therapies. Already seven years ago we were able to push the median ’door-to-needle’ time permanently below 20 minutes. What we had not been monitoring was how well we had kept up the accuracy of our emergengy department (ED) diagnostic process. Prehospital emergency medical services (EMS) have been trained to focus on suspecting thrombolysis-eligible stroke and we usually get also pre-notifications of arriving stroke code patients during transportation, but the diagnosis on admission is an independent clinical judgment as the CT findings are largely nondiagnostic for acute changes.
The admission evaluation of suspected acute stroke is therefore a decisive neurologic checkpoint, building the success of acute treatments such as recanalization therapy, but is complicated by differential diagnosis between true manifestations of stroke and numerous mimicking conditions. Although we have invested a lot on training and standardized ED procedures, time pressure and therapy-geared expectations may blur the diagnostic process.
With this background, we embarked on an in-depth-analysis of the admission and final diagnoses of stroke code patients, as well as misdiagnoses, immediate treatment decisions and their consequences.
MedicalResearch.com: What are the main findings?
Response: In a prospectively collected cohort of 1015 stroke suspect patients the final diagnosis was acute cerebral ischemia (ischemic stroke or TIA) in 663 (65.3%) of the patients. The rate of correct admission diagnosis of acute cerebral ischemia was 91.1%. The overall rate of misdiagnosis in admission evaluation was 14.8% for all arriving stroke code patients when CT-based imaging was used. But for every 100 stroke code patients, only two received unnecessary thrombolytic therapy (tPA), or was left without indicated tPA, due to incorrect admission diagnosis.
Two thirds of the misdiagnosed patients had very mild symptoms, with an admission NIHSS score of only 0-2, which is known to make rapid evaluation demanding. We found that misdiagnosis affected medical management in some way in only half (46.7%) of the misdiagnosed patients, with most of these effects being mild. Importantly, in detailed analysis we identified only 8 cases, less than 1 percent, in which misdiagnosis was likely or possible to have contributed to a worsened outcome, none of which included death.
MedicalResearch.com: What should clinicians and patients take away from your report?
Response: The most important result was that the data supported the safety of highly optimized ’door-to-needle’ times when sufficient task-specific neurological expertise had been accumulated through years of development in a high volume center.
But our findings also illustrate many of the great difficulties of quickly diagnosing stroke patients – especially those with milder symptoms and normal CTs – which should remind us of the importance of focused neurological training for all physicians evaluating stroke code patients. After all, the patients are entitled to a diagnosis that has a rational basis and deserve a doctor with experience and aptitude to treat diverse acute neurological illnesses, only a part of which involve reversing brain tissue ischemia.
MedicalResearch.com: What recommendations do you have for future research as a result of this study?
Response: Optimization of rapid medical management is always possible, but should build on existing expertise, nested monitoring and quality assurance.
One area of future development in emergency department stroke evaluation is more active utilization of rapid magnetic resonance imaging, especially in patients with challenging or unusual clinical syndromes as well as in those stroke thrombolysis candidates with unknown symptom onset time.
Today we face another challenge of detecting early the candidates for rapid endovascular thrombectomy treatment, i.e. large vessel occlusions, which further augments the requirements of neurological and imaging evaluation of a stroke code patient.
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Saana Pihlasviita, Olli S. Mattila, Juhani Ritvonen, Gerli Sibolt, Sami Curtze, Daniel Strbian, Heini Harve, Mikko Pystynen, Markku Kuisma, Turgut Tatlisumak, Perttu J. Lindsberg. Diagnosing cerebral ischemia with door-to-thrombolysis times below 20 minutes. Neurology, 2018;
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