For emergency physician Rachel Garvin, MD, FNCS, properly diagnosing posterior circulation strokes is a passion. But practicing said passion can be like ferreting out a “wolf in sheep’s clothing.”
“It is something that is trying masquerade as something not really that bad,” Dr. Garvin said during her ACEP19 presentation, “Posterior Strokes: A Dizzying Differential.” “That’s what posterior circulation strokes are. People come in (with symptoms that) don’t really seem that concerning but can be absolutely devastating … our job today is to expose this wolf. For you guys in the emergency department to be able to sniff out these patients that are presenting with posterior circulation stroke, so that you’re not missing them.”
Dr. Garvin, an associate professor in the Department of Neurosurgery at UT Health San Antonio, said posterior circulation strokes should make up roughly 20% of all ischemic strokes. But one recent review she participated in found they made up only 12.5%.
“These are being missed,” Dr. Garvin said.
Dr. Garvin said perhaps the best clinical pearl she can share to help emergency physicians diagnose posterior circulation stroke is to get their patient out of bed. Especially if they present with a seemingly benign compliant of dizziness.
“Get them up and walk them,” Dr. Garvin said. “I promise you it does not take a lot of extra time … I know we think we’re making our patients feel bad, feel worse or (say), ‘I’m so sick, I can’t get up.’
“You know what I tell people? ‘You need to get up. Here is an emesis basin, we’ll hold that for you, but we have to see how you can walk.’You will get so much information just from getting your patients up off the stretcher.”
Another practical tip Dr. Garvin suggested was trying to use cranial nerve deficits as a marker to differentiate anterior circulation stroke from posterior circulation stroke.
“The trickiest thing, but the thing that you can really catch, is cranial nerve deficits,” she said. “You will not see cranial nerve deficits in anterior circulation strokes, but you can see them in posterior circulation strokes – and you need to look for them because cranial nerve deficits can be very subtle.”
Sometimes, emergency physicians are tempted to rely on MRIs and other imaging technology to help with their diagnosis. Dr. Garvin noted that those are ancillary methods, not primary ones – such as taking a patient’s history or performing a physical exam.
“Lay your hands on the patients,” she added. “We have gotten very reliant on imaging to tell us what’s going. I will tell you that imaging will not always tell you the story.
“There is a reason why we learn to get a history and physical exam. And this is what I teach to my residents: 99% of the time, a history and physical exam can build your differential diagnosis. You are going to know what’s going on with your patient. All the tests are going to tell you is yay or nay from your differential diagnosis.”
Richard Quinn is a freelance writer from New Jersey.