EAN 2023 | Diagnostic criteria for transient ischemic attacks and the challenges facing accurate diagnosis
Hanne Christensen, MD, PhD, MSci, from the University of Copenhagen, Copenhagen, Denmark, discusses current diagnostic criteria and the difficulties faced by clinicians in diagnosing transient ischemic attacks (TIAs). Traditional definitions of a TIA assume that rapid symptom resolution is indicative of a transient ischemic insult. For example, the World Health Organization (WHO) criteria for diagnosing a TIA is based on a rapidly developed focal neurological deficit, with symptoms of less than 24 hours and no apparent non-vascular cause. However, updated criteria from the American Heart Association published in 2009 recommended a tissue-based approach, necessitating the absence of infarction on brain imaging in addition to symptom resolution for a TIA diagnosis. This change was based on the observation that MRI with DWI demonstrates lesions in ~40% of patients presenting with TIA symptoms, and DWI positivity is associated with a 6-fold increased risk of recurrent stroke at 1 year. Ischemic stroke is typically diagnosed where a DWI-positive lesion is identified. However, some evidence suggests that patients without these DWI lesions can have similar risks of stroke as those with lesions. This makes it difficult for neurologists to effectively determine risk from TIAs. Recorded at the 9th Congress of the European Academy of Neurology (EAN) 2023 held in Budapest, Hungary.
These works are owned by Magdalen Medical Publishing (MMP) and are protected by copyright laws and treaties around the world. All rights are reserved.
Transcript (edited for clarity)
We have two different criteria, which makes things a little bit difficult. We have the WHO criteria originating from somewhere in the 70s, and those were made primarily to support epidemiological research because people wanted to see, is this TIA thing really that innocent? So, that criterion is neurological deficit originating from one vascular territory and with symptoms lasting less than 24 hours, and that is what we’re working with in Europe in general...
We have two different criteria, which makes things a little bit difficult. We have the WHO criteria originating from somewhere in the 70s, and those were made primarily to support epidemiological research because people wanted to see, is this TIA thing really that innocent? So, that criterion is neurological deficit originating from one vascular territory and with symptoms lasting less than 24 hours, and that is what we’re working with in Europe in general.
Then like five, seven, eight years ago, some new criteria were published in the US based on the fact that we realized that often you can see in people with clinical TIA with complete remission, at least if they see the neurologist within 24 hours, that they actually have a lesion, a DWI lesion if you do an MRI scan. And so, they set up a new tissue-based criteria, which included if there was a DWI lesion, then this was no longer a TIA because then there was an infarction on the scan. So that a TIA would be neurological symptoms originating from one vascular territory, leaving no trace behind on the MRI scan. And this basically means that we end up with three groups of patients, those with an infarction on the scan and symptoms lasting for more than 24 hours, those with an infarction on the MRI and symptoms lasting at least according to neurologists shorter than 24 hours, and then those with symptoms lasting below 24 hours and nothing on the MRI scan. This makes a lot of sense. This is about looking at what happens on imaging and testing, especially for doctors, we love to see our clinical impression, the patient history confirmed by something that you can actually see and measure. In that way, it’s good, but what is really complicated, and that’s still the same problem, are those with no MRI signs, because there is certainly evidence that these might have as poor a prognosis as those who do have a DWI lesion. So, at the end of the day whatever you do, you will end up needing somebody clinically to work up these patients, you will need a stroke expert because it’s also deleterious to receive secondary prevention for absolutely no reason. It’s not just cakes you eat.
I mean, I don’t think that has ever really been evaluated, but it is certainly a support for the physician. And we have to be aware that even very experienced neurologists are in doubt. I’ve been working with stroke for 24 years, and I’m not sure all the time but regularly in doubt with these patients. Is it really a TIA or is it not? And in that way, you can be kind of supported by seeing or not seeing a DWI. It could also be an option for organization that if people do have a DWI deficit, then they do not have to be seen by an expert. That could be a consequence which would be good for resources, and experts should only focus on those that do not have a lesion, but it certainly complicates matters.
Read more...
