SGEM#376: I Wonder Why She Ran Away from the HINTS Exam

Date: September 16th, 2022 Reference: Gerlier C, et al.  Differentiating central from peripheral causes of acute vertigo in an emergency setting with the HINTS, STANDING and ABCD2 tests: A diagnostic cohort study. AEM 2021 Guest Skeptic: Dr. Peter Johns has been practicing emergency medicine since 1985 and has been passionate about vertigo education for the last two decades.  He co-authored the Vertigo chapter in the current edition of Tintinalli’s emergency medicine textbook and has a YouTube channel about vertigo with over 16,000 subscribers and five million views. Case: This is a real case seen by Peter and you can see the actual exam findings in a video on his YouTube channel. A 70-year-old woman wakes up with dizziness and presents to the emergency department (ED) later that day.  She’s vomited twice, and describes her dizziness as a constant spinning sensation, which gets worse when she moves her head.  She has some unsteadiness but can walk unaided.  She has no other neurologic symptoms.  In particular, she denies any new significant headache or neck pain, or focal weakness or paresthesia, dysarthria, diplopia, dysmetria, dysphagia or dysphonia, (the so-called Dangerous D’s).  When you examine her, and she is looking straight ahead, you observe that she has horizontal and slight torsional nystagmus beating towards her left ear. That means that the fast component of the nystagmus is horizontal, to the left, and there is a slight rotation with the upper pole of the eyes beating towards the left as well. Background: We have looked at acute vestibular syndrome (AVS) on the SGEM with Dr. Mary McLean who was the guest skeptic on SGEM #310. The bottom line from that episode was that: Dr. Mary McLean "the available evidence does not support the use of the HINTS examination alone by emergency physicians in patients with isolated vertigo or AVS to rule out a posterior stroke." In that episode, the case patient was told they would be admitted to the hospital to have a neurologist do the HINTS exam and decide if an MRI was necessary. But the question remains: can emergency physicians be taught how to use the HINTS exam to make clinical decisions? This is a difficult task, in part because vertigo education for emergency physicians has historically contained lots of  misinformation.  If there’s one thing we learned from the current pandemic, it is that misinformation is easier to spread than to correct. The tsunami of misinformation around COVID-19 has been coined the “infodemic”. We talked about this with Simon Carley on an SGEM Xtra and he emphasized “principles EBM are even more important now than in any time in our career”. There is a great quote by Thomas Francklin in 1787 about misinformation that rings true over two-hundred years later in the age of social media. He said: “Falsehoods will fly, as it were, on the wings of the wind, and carry its tale to every corner of the earth; whilst truth lags behind; her steps, though sure, are slow and solemn.” There is quote from another famous Franklin, Ben, which is apropos to the HINTS exam. "You will observe with concern how long a useful truth may be known, and exist, before it is generally received and practiced on." Myths & Misinformation about Dizziness: Myth: Asking what they mean by dizzy is the most important question to ask a dizzy patient. In fact, the patient's description of the sensation of their dizziness cannot be used to generate a reliable differential diagnosis. Myth: Tables of central vs peripheral characteristics of vertigo are helpful. Let us just say they are not.  You can watch my YouTube video about this for more info. Myth: If it gets worse when you move your head, that means it’s a peripheral cause. All vertigo gets worse when you move your head. If it does not, it probably is not vertigo. Myth: A CT or CTA will prevent you from sending home a stroke presenting with dizzines...