Do TIAs cause syncope? – give your opinion

HI All

A new trick.  I am trying out this online survey feature.

Let me know if you have an opinion or experience in TIAs and syncope.


  1. Seth Trueger says

    My official answer was “yes if in the posterior circulation” (i.e. VB insufficiency) but I still think it’s a fairly uncommon cause of syncope.

  2. It’s a great question and always good to challenge dogma and rethink things.

    IMHO the only mechanism that TIAs would cause transient loss of consciousness with full return to normal neurologic status would be if the thromboembolic TIA affected the reticular activating system and then it self-thrombolysed without permanent neurologic sequellae. My thought is that this cannot happen to the anterior or middle cerebral circulation as you have to wipe out both cerebral cortices to get loss of consciousness and that would not present as syncope.

    However even in the posterior VB circulation, in reality, is it possible to have a transient thromboembolic event that hypoperfuses the RAS enough to cause true syncope without any neurologic sequellae afterwards of brainstem cranial nerve findings, ataxia, etc? For the thromboembolism to be big enough to hypoperfuse the RAS, is it too big to not leave neurologic sequellae? Not sure if there is any evidence out there for that (haven’t looked yet).

    If that is the case, then does that mean that for all high risk factors for stroke, if they present to ED with true syncope (no neuro findings or sx, no head injury, no blood thinners, no headache to suggest SAH) they need CT then MRI (CT bad for posterior fossa) to rule out CVA as a cause and rest of CVA workup?

    Neuro ain’t my bag so FOAMed help is always appreciated.

    • by the way, for me, a good story of true syncope (not vertigo, not ataxia, not dysequilibrium, not seizure, no headache to suggest SAH, no neurologic findings as should be in syncope, no head injury) means my workup will not include CT (nor MRI)

  3. UptoDate and Steve Dunjey said no.
    Thats good enough for me.

  4. And yet it is a common myth perpetuated by interns and junior residents.

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