10.4081/btvb.2022.31
In the current literature, the utility of transient ischemic attack (TIA) diagnosis is under revision by the scientific community and experts. If initially this term was considered a valid diagnostic category, over the years the definition of TIA has been completely subverted, underlining the scientific lability of this nosological entity [...]
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Diego Centonze
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Bleeding, Thrombosis and Vascular Biology
Neurovascular Medicine
Is transient ischemic attack a minor stroke?
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Bleed Thromb Vascul Biol
Diego Centonze
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Department of Neurology, IRCCS Neuromed, Pozzilli; Synaptic Immunopathology Lab, Department of Systems Medicine, University of Rome Tor Vergata, Rome
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Pan Y, Elm JJ, Li H, et al. Outcomes associated with clopidogrel-aspirin use in minor stroke or transient ischemic attack. JAMA Neurol 2019;76:1466.
Is transient ischemic attack a minor stroke?
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                                                                                                                       EDITORIAL

Is transient ischemic attack a minor stroke?
Ettore Dolcetti,1 Antonio Bruno,1 Diego Centonze1,2

Department of Neurology, IRCCS Neuromed, Pozzilli, Italy; 2Synaptic Immunopathology Lab, Department of Systems Medicine,
1

University of Rome Tor Vergata, Rome, Italy




    In the current literature, the utility of transient is-                  covery of the neurological disorder, for a long time TIA
chemic attack (TIA) diagnosis is under revision by the                       was considered a relatively benign condition compared
scientific community and experts.1 If initially this term                    with minor or major stroke, reflected in a strong minimiz-
was considered a valid diagnostic category, over the years                   ing of associated medium- and long-term consequences.
the definition of TIA has been completely subverted, un-                     Further studies on patients affected by TIA showed an in-
derlining the scientific lability of this nosological entity.                creased long-term risk of recurrent stroke and accumula-
In 1975, a committee from the US National Institutes of                      tion of disability similar to patients affected by minor
Health decided to provide a temporal framework defini-                       ischemic stroke (or minor stroke).3




                                                                                                       ly
tion of TIA, including in this diagnosis all those focal neu-                    In particular, it has been demonstrated that prediction




                                                                                              on
rological syndromes lasting between 2 and 15 minutes and                     of recurrent major stroke in patients with high risk factors,
sometimes up to 24 hours, characterized by a complete                        identified in a clinical score assigned by using the ABCD2
spontaneous resolution in the absence of apparent brain                      and ABCD3 I scale (Age, Blood pressure, Clinical fea-



                                                                                         e
injury (Table 1).2 Due to its transience and to the full re-                 tures, Duration, Diabetes / Dual TIA) is comparable in pa-
                                                                                  us
                                                                             tients affected at onset by TIA or minor stroke.4-6
                                                                                 The marked improvement of neuroimaging and the
                                                                             broader awareness of patients to rapidly access to emer-
                                                                             al

    Correspondence: Diego Centonze, Synaptic Immunopathology                 gency care allowed the acquisition of new insights regard-
                                                                   ci

    Lab, Department of Systems Medicine, University of Rome Tor              ing clinical presentation and course of stroke, thus making
    Vergata, Via Montpellier 1, 00133 Rome, Italy.                           TIA an outdated stand-alone entity of scarce use in clini-
                                                                 er



    E-mail: centonze@uniroma2.it
                                                                             cal neurological practice.
                                                                m




    Key words: TIA, Minor stroke, Neurovascular medicine.                        In particular, the introduction of magnetic resonance
                                                                             imaging (MRI) in the clinical practice since 1990 showed
                                                     om




    Contributions: The authors contributed equally.                          that many TIA diagnoses were characterized by a central
    Conflict of interest: DC is an Advisory Board member of Almirall,
                                                                             nervous system (CNS) damage radiologically detectable.
                                                                             In 2009, the American Heart Association renamed TIA as
                                               -c




    Bayer Schering, Biogen, GW Pharmaceuticals, Merck Serono, No-
    vartis, Roche, Sanofi-Genzyme, and Teva and received honoraria           a transient entity represented by focal ischemia of the
                                                                             brain, retina or spinal cord in the absence of acute radio-
                                      on




    for speaking or consultation fees from Almirall, Bayer Schering,
    Biogen, GW Pharmaceuticals, Merck Serono, Novartis, Roche,
    Sanofi-Genzyme, and Teva. He is also the principal investigator in       logical infarction. If this statement, on one hand, has led
                                                                             to a more accurate definition of the diagnosis, on the other
                                N




    clinical trials for Bayer Schering, Biogen, Merck Serono, Mit-
    subishi, Novartis, Roche, Sanofi-Genzyme, and Teva. His preclin-         hand it has increasingly contributed to the development
    ical and clinical research was supported by grants from Bayer
                                                                             of technology for high-field MRI (3T and more recently
    Schering, Biogen Idec, Celgene, Merck Serono, Novartis, Roche,
    Sanofi-Genzyme and Teva. ED and AB declare that the research             7T) that have allowed to detect even relatively small or
    was conducted in the absence of any commercial or financial rela-        transient lesions associated with a brain injury. The in-
    tionships that could be construed as a potential conflict of interest.   creasingly widespread use of MRI in the study of neuro-
                                                                             logical syndromes in hyperacute phase, which partially
    Funding: None.
                                                                             replaced computerized tomography over the years, al-
    Received for publication: 31 March 2022.                                 lowed to further circumscribe the TIA as an acute transient
    Accepted for publication: 30 April 2022.                                 neurological deficitary entity associated with a restricted
    This work is licensed under a Creative Commons Attribution Non-
                                                                             diffusivity in the sequences of diffusion weighted images
    Commercial 4.0 License (CC BY-NC 4.0).                                   in the absence of findings in T2 sequences (i.e. T2
                                                                             FLAIR), or absence of findings both in DWI and in T2
     Copyright: the Author(s), 2022                                          sequences,7 identifying brain infarction as a risk factor for
    ©

    Licensee PAGEPress, Italy
    Bleeding, Thrombosis and Vascular Biology 2022; 1:31
                                                                             increased long-term disability.8,9
    doi:10.4081/btvb.2022.31                                                     This clarification allows TIA to be classified as a
                                                                             purely radiological entity, as it is indistinguishable from

                                                Bleeding, Thrombosis and Vascular Biology 2022; 1:31
                                               Is transient ischemic attack a minor stroke?                                                   49



Table 1. Time evolution of the definition of transient ischemic attack.
Year   Reference                                             Definition
1975   US, National Institutes of Health (NIHSS), Bethesda   Focal neurological syndromes between 2 minutes to 24 hours with complete
                                                             spontaneous resolution in absence of apparent brain injury
2009   American Heart Association (AHA)                      Transient entity represented bifocal ischemia of the brain, retina or spinal cord in
                                                             absence of acute radiological infarction
2014   Brazzelli et al.7                                     Acute transitory neurological deficit associated in MRI with a restricted diffusivity
                                                             in absence of findings in T2 sequences, or absence of findings both in DWI and in T2
                                                             sequences




a minor stroke without residual clinical neurological
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                                     om




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                                         Bleeding, Thrombosis and Vascular Biology 2022; 1:31
