Transcription
This is a basic, simplified approach to the disip pati part two by Peter Johns. If you haven't already watched part one, I suggest you do so, as you'll see how to diagnose BPPV.
In part two, we'll be looking at patients with acute vestibular syndrome and talk about how you can look for obvious and subtle signs of stroke and show how to do the HINTS exam.
Now, acute severe dizziness or acute vestibular syndrome (AVS) is where you have ongoing vertigo lasting many hours or days, and develops over a variable period of time. They have spontaneous nystagmus, their vertigo is worse with changes in head position, they have nausea or vomiting, and they're not walking normally. If you compare that to BPPV, which has short, less than one minute episodes with no ongoing vertigo and no spontaneous nystagmus, you can see quite a difference in the presentation.
Acute vestibular syndrome, most of them won't turn out to have vestibular neuritis. A smaller percentage may be having a stroke. How do you tell? Well, first of all, if they're having obvious stroke symptoms, they're having a stroke. If you have new focal weakness, paresthesias, facial droop, difficulty speaking, swallowing, diplopia, abnormal finger-nose testing, well, then they're having a stroke. You need to treat them like you do stroke patients.
Now, they may have subtle signs of stroke, such as they're unable to walk, not just unwilling, but you stand them up and they're falling left and right, and they're unable to walk. Or if you ask them to sit with their arms folded across their chest, they're just falling over. Well, then they're also having a stroke. Or they have sustained significant headache, well, then you worry about a cerebellar hemorrhage. If they have sustained significant neck pain, you worry about vertebral artery dissection.
Now, the typical presentation of vestibular neuritis is that again, it comes over a variable amount of time, but it's constant. If you ask them how long the longest episode of continuous spinning was, it'll be many hours or days. It won't just go away if they keep still, and the vertigo will be with nausea and vomiting and unsteady gait. They may or may not have had a viral illness, and many of them haven't. And the peak intensity is usually in the first day, and then after a couple of days, it starts to get better, but can take weeks or months to completely resolve. And again, the vertigo is made much worse by head movement. It's not all vertigo, just because they say when they go from lying to sitting that they get more dizzy, doesn't mean they have BPPV.
Now, here's what they typically look like, as opposed to our BPPV patient who just was sitting in a chair looking pretty good. This one prefers to lie in bed with eyes closed on a side, showing you his bad ear, which is his right ear. And if you ask them to get up and walk, uh, this is what you see. You can see that he's not really happy about walking. He's a little unsteady, he's kind of a bit broad-based, he's kind of has a little trouble turning around there, and he looks like he might have had a few drinks, but he's certainly able to walk, even with his intense vertigo, which he certainly has. An unsteady tandem gait here. So that's what BPPV, sorry, that's what Vitis patients look like, not BPPV. And I can tell you this patient did not have any of the obvious or subtle signs of stroke that we just discussed.
But could a patient like this with acute vestibular syndrome and no obvious focal neuro deficits still be having a stroke? The answer is apparently yes. Stroke can mimic, can mimic vestibular neuritis. Now, how commonly does this actually occur in the emergency department in patients with acute vestibular syndrome? It's not entirely clear. Certainly not zero. It's not 20%. Is it 5%? 10%? 1%? It's a concern. So what can we do?
Well, this is the HINTS examination. It's a three-component test: the Head Impulse, Nystagmus, and Test of Skew. That's where the HINTS acronym comes from. I usually examine them in the following order: the Nystagmus, Test of Skew, then Head Impulse test. Now, the HINTS exam is only to be used in patients with acute vestibular syndrome with ongoing vertigo and the nystagmus. It's not a divining rod that differentiates every cause of vertigo into central versus peripheral. It's only with acute vestibular syndrome. So if they don't have nystagmus, no HINTS exam for you.
The first component is looking at the nystagmus. Observe which direction the fast component of the nystagmus is as the patient is asked to gaze left or right. In patients who have vestibular neuritis, they do not change direction depending on which way they're looking. The nystagmus is usually horizontal with a rotary component, and the fast component is away from the affected ear, which is opposite to BPPV where the torsional component is towards the affected ear. In this case, it's away. And if they look away from the affected ear, the nystagmus will increase in intensity, and when they look towards the affected ear, either it goes away or it's less. It can be seen better if you don't ask them to look at your finger or fixate on anything. So just have them gaze around the room or use a blank piece of paper on the side of their and ask him to look through that piece of paper to have stopped them from fixating on something.
So in this man with vestibular neuritis, you can see that even on primary gaze, he had nystagmus. When he looks off to the left, which is away from his affected ear, it increases, and you can see there is a rotary component. See how that's that eye is torting towards his, uh, left ear? We're going to see it again from another angle. He's got spontaneous nystagmus just looking straight ahead. Not all of them do. Some of them, you only see the nystagmus when they're looking off away from the affected ear. But he has spontaneous nystagmus on primary gaze, it increases when he looks away from his affected ear, decreases when he looks towards his affected ear, and you can see the torsional component. You see the little red vessels torting.
Now, in a stroke, the nystagmus may change direction depending on which side they're looking at. But it, it usually don't see that. There's only about 20% of the cases in the HINTS exam did have direction-changing nystagmus. So if you see the nystagmus changing direction, that means they're having a stroke in acute vestibular syndrome. So it's a very specific test. Unfortunately, you don't see it all the time or very often, so it's not very sensitive.
Here is a young man who has direction-changing nystagmus. He looks to the right, and his nystagmus is to the right. He looks to the left, and his nystagmus is to the left. He is not having a stroke. In fact, he's actually has another central cause, which is intoxication, but that's direction-changing nystagmus.
Now, the next test in the HINTS exam is the test of skew. Looking for vertical skew deviation. And someone who's having acute vestibular syndrome, if they have vertical skew deviation, they're having a stroke. So here's how you do it. You move your hand, cover, uncover that eye, cover the next one. You can see he's still having the nystagmus, but there's no vertical deviation of his eyes.
In this man who was having a stroke and had skew deviation, watch how, in particular, his right eye goes up and then his left eye dips down a little bit as they're both covered and uncovered. So watch it. Eye goes up here, and then down a little bit there. Up and then down. There's a medial deviation as well, but there is vertical skew deviation. So that means this man's having a stroke. Indeed, he was.
Now, the third component of the HINTS exam is a head impulse test. This is a little trickier, but you can learn it. It's not that hard. It should be abnormal on one side if they have vestibular neuritis causing their acute vestibular syndrome. If you have acute vestibular syndrome and you do a head impulse test and it's normal on both sides, then they're having a stroke. So this is a little counterintuitive because a normal head impulse test in someone with acute vestibular syndrome is worrisome. But think of it this way: the head impulse test is looking to see if you have a nerve problem. If you have acute vestibular syndrome and you don't see a nerve problem, then they're probably having a brain problem.
So here's what the head impulse test looks like. Note how I'm grabbing a little higher, right on his skull, as opposed to on his mandible. And you kind of turn his head back and forth in a random kind of fashion. Now, he has a lot of nystagmus. So the first time when I turn it to the left, you'll see a little nystagmus. It looks just like it was a catch-up saccade, but it's not. Watch when I turn his head to the right, the increased intensity of the, see that? That was the catch-up saccade again on the, that's a normal turning to the left. When you turn towards his affected ear, right ear, that's when you see the abnormal catch-up saccade, and that means he has an abnormal head impulse test, and therefore he has a nerve problem. So he probably doesn't have a brain problem.
So in our patient who has acute vestibular syndrome, had no obvious or subtle concerns for stroke, HINTS exam was reassuring because he has a positive head impulse test, he had unidirectional nystagmus, you had no vertical test of no vertical vertical skew. What do you do with a guy like that? You do a CT or an MRI or refer to neurology? No, you just treat them like you normally would with vestibular neuritis and send them home.
So the takeaway has two points to make. First of all, as with BPPV, if you have nystagmus, you don't get a Dix-Hallpike test. And if you have no nystagmus, you don't get a HINTS exam. So again, just to make this perfectly clear, when would you perform both the Dix-Hallpike test and the HINTS exam on the same patient? Basically never. Because either you have acute vestibular syndrome and you have nystagmus, so then you don't have BPPV, so you don't need to do the Dix-Hallpike test, and in fact, it'll just confuse you and make the patient feel worse. Or if you don't have acute vestibular syndrome, so you have done a nystagmus, then you don't do the HINTS exam because people without acute vestibular syndrome will have a normal head impulse test, and then you'll be worried they're having a stroke.
So what we covered in these two talks was BPPV and acute vestibular syndrome, which is mostly vestibular neuritis, but sometimes cerebellar stroke. What we didn't cover were the many other causes of vertigo: vestibular migraine, Meniere's, a lot of different diseases. But my point was that I want you to understand the basics, and then once you understand that, you can branch out and learn the other more subtle causes of vertigo. And I don't want you to get discouraged by the fact that you're going to see a number of patients with dizziness, not every patient gets a definitive diagnosis. Think about it, when you see patients with chest pain or abdominal pain, do you make a diagnosis, a definitive diagnosis in all those patients? On a substantial subset, you do not. And that's you accept that. And chest and abdominal pain, well, you have to accept that with vertigo as well.
The other thing I'd just like to bring up is that, you know, the disease severity in vertigo also varies quite a bit. I saw a middle-aged man who took an ambulance to the hospital with BPPV. Every time he stood up, he got dizzy. So he lay back in bed, he stayed in bed for three days, and finally came to the hospital by ambulance. And I thought, oh, he's going to have vestibular neuritis, he's so sick. But he wasn't spinning. Off he stood still, and I did the Dix-Hallpike on him. He had no nystagmus, so spontaneous. And I did the Dix-Hallpike and the Epley maneuver and cured him.
Just recently, less than a month ago, I saw a lady, a young lady, who said every time she bent over, she got so dizzy she fell down 11 times in two days. While she was waiting to be seen, she said she actually reached over to get a magazine, fell over onto the floor, and rolled out into the hall. Cured her with the Epley maneuver. Now, none of these patients, you know, had had ongoing vertigo or spontaneous nystagmus.
So in conclusion, BPPV and vestibular neuritis should look clinically distinct from each other. In patients with BPPV, patients with acute vestibular syndrome, stroke can be confused with vestibular neuritis. So in acute vestibular syndrome, look for the obvious and subtle signs of stroke, and then use a HINTS exam to reassure yourself that it is in fact vestibular neuritis. Thanks for watching.