Recently, I had the experience of being an EMS patient while on vacation. While walking in the downtown of a large city, I had a sudden onset of severe, unremitting vertigo that was associated with an inability to walk unassisted. This was associated with severe nausea and vomiting.
I tried to get the vertigo to stop by remaining still and fixating my gaze on one spot. This did not work. The inability to extinguish vertigo by point fixation is a hallmark of central vertigo. That is to say, central vertigo arises from a problem with the brain, not from the vestibular apparatus of the ear, which is referred to as peripheral vertigo. With these, I knew I was having a stroke.
My son, who is also an MD, was with me and called EMS. On their arrival, he tried to explain what was happening, but they seemed distracted by the vomiting and assumed it was a GI or intoxication problem. I was taken to the ER and initially placed in a non-urgent area. With my son’s insistence, a stroke alert was called, and I was taken to CT and seen by a neurologist.
The dry CT scan was negative for bleeding, and a contrast scan was also normal. However, the neurologist determined that I was indeed having a stroke based on my presentation and exam findings. Initial CTs can appear normal when having a stroke. I was given TNK (a thrombolytic) and shortly thereafter the symptoms resolved.
I am otherwise healthy and quite fit for my age, with normal BP and normal blood sugar. I am very active, and I don’t smoke. But why did I have a stroke? It turns out, I have a PFO (patent foramen ovale).
Before birth, everyone has a flap-like hole in the heart called the foramen ovale. It allows blood to bypass the lungs, which aren’t used in utero. After birth, the lungs expand, and the flap normally seals shut. In about 25-30% of adults, that flap never fully seals. When it stays open, it’s called a patent (open) foramen ovale.
The PFO allows a small clot to travel from the leg to the brain, bypassing the lungs. I suspect a long plane ride, a couple of days before this event, caused a subclinical clot to form in my leg and travel to my brain.
It is interesting to note that up to 14% of strokes would be missed by the FAST stroke assessment mnemonic alone. This is why the AHA added BE to the mnemonic in 2017: BE FAST (Balance, Eyes, Face, Arm, Speech, Time).
This was to recognize that posterior circulation strokes (cerebellum, brainstem, visual cortex) may present with balance problems or vision issues and not the usual facial, motor, sensory, or speech deficits.
EMS providers need to remember these less common stroke symptoms and maintain a high index of suspicion. This is very important as there is only a 4.5-hour window to get thrombolytic treatment after the onset of symptoms. That time includes transport, ED evaluation, CT, preparation of the medication, and a nurse available to do the administration.
In my case, even though EMS was called immediately, all these steps still took 2 hours from the onset of symptoms before I actually received the medication. I shudder to think of what the outcome would have been if it happened while traveling in a more remote or rural area, or if my son had not been there to advocate for me.
References:
Aroor, S., Singh, R. and Goldstein, L.B. (2017) ‘BE-FAST (Balance, Eyes, Face, Arm, Speech, Time): Reducing the proportion of strokes missed using the FAST mnemonic’, Stroke, 48(2), pp. 479–481. doi:10.1161/STROKEAHA.116.015169.
