Women experiencing a minor stroke or transient ischemic attack (TIA) are less likely to be diagnosed with a stroke compared to men – even though they describe similar symptoms in emergency departments.
“In our study, men were more likely to be diagnosed with TIA or minor stroke, and women were 10 per cent more likely to be given a non-stroke diagnosis, for example migraine or vertigo, even though men and women were equally likely to report atypical stroke symptoms,” says study lead author Dr. Amy Yu, MD, a stroke neurologist at Sunnybrook Health Sciences Centre and assistant professor at the University of Toronto.
The findings of the study are published in JAMA Neurology and were presented May 22 at the European Stroke Organisation Conference in Milan, Italy.
The study found men and women equally described atypical stroke symptoms such as dizziness, tingling or confusion which are not commonly thought of as related to stroke.
Typical symptoms of stroke are sudden weakness, face drooping, or speech difficulties.
A TIA occurs when there is temporary interruption of blood flow to the brain, and is often a warning sign of another stroke.
TIAs can also be associated with permanent disability.
Currently it can be argued that the approach to investigating transient ischemic attack (TIA) and minor stroke is a compromise between timeliness of investigation and accuracy of diagnosis.
Diagnostic accuracy hinges on identification of tissue injury, i.e., infarction.
However, the tools that can be used to achieve this degree of accuracy, e.g., magnetic resonance imaging (MRI), are not always readily available at the point of care.
This dilemma is also linked to the evolving definition of TIA and stroke, which has changed over the past few decades to accommodate both clinical utility and biological significance.
The initial description of TIA as a transient neurological deficit of suspected vascular origin lasting <24 h has been used widely throughout epidemiological studies and for pragmatic clinical decision-making.
As such, it has been a useful construct that could be applied in any clinical setting requiring nothing more than the clinician’s judgment from the patient’s history and examination findings, facilitating rapid diagnosis.
However, this definition has been abandoned in light of recent imaging data that demonstrates that about 50% of these patients have evidence of infarction on diffusion-weighted MRI (DWI; Easton et al., 2009).
Therefore, TIA has been re-defined as a transient neurological deficit of any duration without evidence of parenchymal injury, while symptoms that are accompanied by evidence of infarction now constitute stroke and portend a much greater risk of recurrent stroke (Easton et al., 2009).
While the new definitions of TIA and stroke are much more accurate regarding the biological consequences of cerebral ischemia (Johnston et al., 2000; Kleindorfer et al., 2005; Coutts et al., 2012), they create new dilemmas for clinicians and investigators.
The new TIA definition is heavily reliant on MRI scan, which is not readily available in most Emergency Departments on a 24-h basis, making it more difficult to differentiate TIA from stroke. Conversely, patients without parenchymal damage often have uneventful recoveries and many are likely to not have had cerebral ischemia at all but rather a mimic of stroke or TIA, such as migraine (Prabhakaran et al., 2008).
In these patients, the diagnostic label of TIA is therefore inaccurate and could lead to unnecessary investigations and interventions.
Despite recent remarkable advances in imaging cerebral ischemia, the discordance between clinical utility (i.e., rapid diagnosis) and biological insight (i.e., accurate assessment of tissue injury) is not fully resolved. In 2013, the American Heart Association (AHA) proposed a modification of the TIA definition to allow for the diagnosis of TIA to be made without MRI (Sacco et al., 2013) but this still does not clarify the possibility of concurrent parenchymal damage, as computed tomography (CT) alone is insufficient to rule this out.
For those who have no evidence of infarction on MRI scan, it is often unclear if these patients had transient cerebral ischemia at all.
Further confounding these issues is recent evidence showing that some TIA patients may experience persistent deficits undetected by conventional clinical and imaging assessments.
Markers of brain injury following TIA remain an active area of research but to date no supplementary tests have been approved for use in clinical practice.
Current techniques that are used in the diagnosis of stroke and TIA have important limitations for both rapid clinical decision-making and for understanding the functional consequences of cerebral ischemia.
In this review article, we will examine the role that anatomical imaging, neurophysiological investigations and functional/behavioral assessment may have in providing accurate biological insight in a timely manner for TIA/minor stroke diagnosis.
Discrepancy in diagnoses
“Our study also found the chance of having another stroke or heart attack within 90 days of the diagnosis was the same for women and men,” adds senior author Dr. Shelagh Coutts, MD, a stroke neurologist with Alberta Health Services at Foothills Medical Centre, associate professor at the University of Calgary’s Cumming School of Medicine (CSM) and member of the Hotchkiss Brain Institute at the CSM.
Researchers say while further research is needed, it is possible that patient reporting of symptoms, interpretation of symptoms by clinicians, or a combination of both, could explain the discrepancy in diagnosis among men and women.
“Our findings call attention to potential missed opportunities for prevention of stroke and other adverse vascular events such as heart attack or death in women,” adds Coutts.
Previous studies on this topic have focused on patients diagnosed with stroke. Researchers in the current study included 1,648 patients with suspected TIA who were referred to a neurologist after receiving emergency care from 2013-2017, regardless of their final diagnosis.
Spotlight on atypical symptoms
Researchers note it is an important opportunity for the public and clinicians to be aware of atypical symptoms of TIA.
“What’s important to recognize in stroke is that the brain has so many different functions and when a stroke is happening, people can feel different things beyond the typical stroke symptoms,” says Yu.
“Accurately diagnosing TIA and stroke would change a patient’s treatment plan and could help prevent another stroke from happening.”
More information: Amy Y. X. Yu et al. Sex Differences in Presentation and Outcome After an Acute Transient or Minor Neurologic Event, JAMA Neurology (2019). DOI: 10.1001/jamaneurol.2019.1305
Journal information: Archives of Neurology
Provided by University of Calgary