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Nearly 10 Percent of Strokes Are Misdiagnosed (At Least Initially) in the Emergency Department

ARTICLE IN BRIEF

Misdiagnoses of stroke in the emergency department — particularly for patients who present with milder conditions, as well as comorbid headache and vertigo — point to the need for greater education and collaboration among emergency physicians and neurologists, a new study suggests.

About 9 percent of patients who present to the emergency department (ED) with stroke, transient ischemic attack (TIA), or subarachnoid hemorrhage are initially misdiagnosed, according to a new analysis published in the March 29 online edition of Neurology. Many of these misdiagnosed patients present with mild, non-specific or transient neurological complaints, the study authors reported.

Responding to the report, neurologists and ED physicians told Neurology Today they need to find new ways to work together to reduce mistakes. They cautioned, however, that because symptoms such as headache, vertigo, and nausea are so common in the ED and have so many different causes, that it would be challenge to eliminate errors completely without conducting neuroimaging on all patients with such symptoms.

Stroke is the fourth most common misdiagnosis among major diagnostic errors, and the study aimed to clarify the true rate of stroke misdiagnosis in the ED. In previous studies, the rate ranged from as low as 4 percent to as high as 64 percent, compared to an ED misdiagnosis rate of 2 percent for myocardial infarction.

The current paper analyzed studies that reported on 15,721 patients and found that roughly 9 percent of cerebrovascular events are missed at initial ED presentation. When complaints were mild, non-specific, or transient, misdiagnoses ranged from 24 to 60 percent. The study authors suggested that approximately 100,000 cerebrovascular events are missed every year in the United States.

Study author Jonathan A. Edlow, MD, FACEP, professor of medicine and emergency medicine at Harvard Medical School and vice-chair of the department of emergency medicine, said the patient with the slurred speech and unilateral drooping face is not [usually] misdiagnosed; rather misdiagnoses occur for inpatients with the transient, mild, and non-localizing symptoms, who may have become dizzy at home but then presented as completely fine in the ED.

Sometimes the patients do not offer a “crisp and clean” history, and sometimes doctors don't ask the right questions, he said. Especially important is establishing an abrupt onset of symptoms. In a typical shift, he said he sees many cases of headaches and dizziness, and a very small percent is due to a serious cerebrovascular problem — most are migraines or a headache from a febrile illness or urinary tract infection. The same is true with dizzy patients.

“I think we can do better than we are [currently doing], and we can certainly do better with patients who have dizziness,” he said. “The traditional diagnostic algorithm that has been taught for decades is not evidence-based or helpful. It's built on flawed data from 40 years ago. Newer data focus on timing of the dizziness and potential triggers, and it is a much more rational way of creating a differential diagnosis.”

“But the notion that we're going to get to 100 percent is not right, and not doable,” Dr. Edlow said. “It would mean massive over-testing on patients who don't have strokes. It wouldn't be cost-effective, and it would gum up the works in the ED. The notion that we can hit perfection is not realistic.”

EXPERTS COMMENT

“This study seemed very thorough with excellent statistical analysis. The findings are very important and coincide with my clinical experience,” said Marilyn Rymer, MD, professor of neurology at the University of Kansas Medical Center.

Issues with dizziness and vertigo needed to be looked at closely, she said, recalling a case that was dismissed involving a young patient who presented with neck pain, dizziness, and a headache; the patient was subsequently diagnosed with a vertebral artery dissection,

“We need increased awareness by ED physicians, particularly with mild symptoms, maybe a checklist, but there's no foolproof way to detect some issues without imaging, and that's the catch-22,” she said. “How do we responsibly select patients for advanced imaging?”

S. Andrew Josephson, MD, FAAN, director of the University of California, San Francisco neurohospitalist program and medical director of inpatient neurology, said that the study was well done but that the limitations of the data were clear. For example, it would be interesting to know what the rate of misdiagnosis of these same patients would have been among neurologists. “We assume it's not zero,” he said.

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DR. JONATHAN A. EDLOW: “The traditional diagnostic algorithm that has been taught for decades is not evidence-based or helpful. Its built on flawed data from 40 years ago. Newer data focus on timing of the dizziness and potential triggers, and it is a much more rational way of creating a differential diagnosis.”

He also would have liked to know what the consequences were to the people who were misdiagnosed. Were they hurt because of the delay, or were they such minor symptoms that the delay was unimportant?

It's important not to read the study as a criticism of emergency department physicians, he said, who see thousands of cases a year that involve headache or dizziness, and have to determine which ones need additional testing.

“It's wrong to let neurologists off the hook here,” Dr. Josephson said. “This should be a call to action for us to help our emergency medicine colleagues and give them tools to know when to call us and when to order additional testing. Some of these consultations may be through telemedicine or other remote technologies — it's a partnership.”

Hugo J. Aparicio, MD, MPH, assistant professor of vascular neurology at the Boston University School of Medicine, said he would like to see more attention paid to “stroke mimics,” a nonvascular disease that presents with stroke-like symptoms, like hypoglycemia, epilepsy and multiple sclerosis.

“In the study, only 25 percent of the patients presented with stroke mimics. In our institution, with a stroke consultation service, we likely evaluate a higher proportion of stroke mimics because the threshold to consult neurology is low,” Dr. Aparicio said.

He agreed with Dr. Josephson that a push for better education for the emergency department is needed, acknowledging that many centers of care do not have neurologists or the ability to do telemedicine. Outreach is needed to those in non-teaching hospitals, non-urban areas, and rural centers to find out how they address stroke systems of care, he said, adding: “Very often the ED may be overwhelmed or understaffed and they are going to miss strokes simply due to gaps in the system.”

David Wang, DO, FAHA, FAAN, director of the Comprehensive Stroke Center at OSF Saint Francis Medical Center in Illinois and the chair-elect of the AAN Stroke Section, said that to minimize misdiagnosis, a good history and neurological exam coupled with brain imaging can help. For example, patients presenting with TIA or vague symptoms like vertigo or headache often have a normal neurological examination. These patients should have a brain magnetic resonance image (MRI) rather than computed tomography since MRI is much more sensitive to detect any strokes.

“A good history and neurological exam can often give the physician some clue as to what imaging test should be done to help with the diagnosis; in the instance of headache, it might be a recurrent migraine rather than an intracranial hemorrhage,” Dr. Wang said.

“The particular challenge we all face is not to miss a stroke that is in the treatment time window – a misdiagnosis can potentially have a major impact on the brain and patient,” he added.

“It is a learning process for ED physicians and neurologists can be of help,” Dr. Wang continued. “Using tools such as the Face Arm Speech Time (FAST) exam can help them recognize strokes. Stroke should be suspected if a patient presented with vertigo plus other neurological deficits.”

Dr. Edlow, the study author, said that he thinks ED physicians will want to work with neurologists, particularly after seeing the data. But he pointed out that most neurologists have significantly more time to work with a patient, whereas he and his ED colleagues often have a few minutes to make an assessment. In addition, neurologists are almost always seeing the patient after some time has elapsed compared to when the initial physician sees the patient, and during this time, additional history, physical findings, and results of investigations are usually available.

“Educational solutions are important, but the reality is that these things take time to penetrate,” he said. “Neurological emergencies are more complicated than some other issues that come in. If someone has chest or belly or back pain, there is a clear algorithmic approach, but if someone has dizziness, it's a much more vague place to start and there are limitations to the diagnostic tests.”

EXPERTS: ON STROKE MISDIAGNOSES IN EMERGENCY DEPARTMENTS

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DR. MARILYN RYMER: “We need increased awareness by ED physicians, particularly with mild symptoms, maybe a checklist, but theres no foolproof way to detect some issues without imaging, and thats the catch-22. How do we responsibly select patients for advanced imaging?”

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DR. HUGO L. APARACIO said outreach is needed to those in non-teaching hospitals, non-urban areas, and rural centers to find out how they address stroke systems of care. “Very often the ED may be overwhelmed or understaffed, and they are going to miss strokes simply due to gaps in the system.”

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DR. S. ANDREW JOSEPHSON: “This should be a call to action for us to help our emergency medicine colleagues and give them tools to know when to call us and when to order additional testing. Some of these consultations may be through telemedicine or other remote technologies — its a partnership.”

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DR. DAVID WANG: “Tools like the positive FAST exam or [looking for] vertigo plus other neurological findings can make one think of stroke. It is an ongoing learning process, and any missed diagnosis should be reviewed by both ED physicians and neurologists at the department level as part of the quality improvement process.”

LINK UP FOR MORE INFORMATION:

•. Tarnutzer AA, Lee S-H, Robinson KA, et al. ED misdiagnosis of cerebrovascular events in the era of modern neuroimaging: A meta-analysis http://neurology.org/lookup/doi/10.1212/WNL.0000000000003814. Neurology 2017; Epub 2017 Mar 29.