April 2017

Approach to Dizziness

Dizziness3 Chapters

Sign in or subscribe to listen

No me gusta!

The flash player was unable to start. If you have a flash blocker then try unblocking the flash content - it should be visible below.

David S. -

Excellent! I have to agree, this is the best approach I have encountered. Quick question though, where does an acephalic migraine fit in to this approach as a cause of dizziness?

Jess Mason -

Thanks David. I think for some of these more uncommon etiologies of dizziness, such as vertiginous (vestibular) migraine or possibly acephalic migraines, the ED may not be the best place to diagnose this. If patients are having recurrent episodes of vertigo or dizziness and that is on your differential, perhaps a neurology referral is the next best step. It's hard to fit that into one of the categories Stuart and I discussed, because it may be isolated or there may be associated symptoms, such as tinnitus and various types of nystagmus, and it may be constant or triggered. Of course, if any of the features of a central etiology are present, the patient should still get a work up for cerebrovascular causes, and the final diagnosis can be left for the neurologist at a later time.

David S. -

Sounds great, thanks! Just noticed I typed acephalic instead of acephalgic migraine. The ol' dreaded headless migraine... that is the worst type to figure out :)

Peter Johns, M.D. -

Vestibular Migraine is the second most common cause of vertigo, after BPPV. Knowing the diagnostic criteria for vestibular migraine is the first step to making the diagnosis. Once you know what they present like, you will see them in the ED. The eye only sees what the brain knows.

You do not need to be a neurologist to make this diagnosis, any more than you need to be a neurologist to make the diagnosis of migraine.

David S. -

Dr. Johns, I think your comment gets to my initial concern. I have heard the vertiginous migraines are more common than we once thought. The problem is that they can cause constant symptoms and I cannot figure out how to be certain this isn't from a central lesion. Can you simply rely on the criteria (+headache, +N/V, +Photo/phonophobia, lasting greater than 1min, but less than 72 hours) to accurately diagnosis migraine instead of a TIA or central lesion? Migraine would show up on a HINTS exam like a central lesion, yes? Thanks!

Peter Johns, M.D. -

David S., You had some additional questions which I'll address. There is no imaging that can confirm vestibular migraine. Despite that, it is the most common central cause of vertigo. Just one that almost is never diagnosed in the emergency department, yet no patients have a bad outcome despite this. They just suffer without a proper diagnosis.

HINTS should only be used if the patient has Acute Vestibular Syndrome. ie, continuous, ongoing vertigo AND nystagmus. This was not mentioned in the podcast, but David Newman Toker has said this many times, and it is mentioned in the one of the podcast's references. Most patients with vestibular migraine do not have nystagmus, and so HINTS should not be applied.

I'll outline the most accepted diagnostic criteria here:

Moderate or severe episodes of vertigo lasting 5 minutes to 72 hours
Past or current history of migraine

5 or more episodes of vertigo, at least 50% of which have one of three migrainous features:
1 visual aura, 2 photophobia or phonophobia, 3 Typical migraine headaches

Typical migraine headaches should have at least two of the following four qualities:
1. unilateral, 2. pulsating, 3. moderate or severe intensity, 4. aggravated by routine activity.

In addition, the patient’s clinical presentation should not better accounted for by another headache or vestibular problem.

They key point is they have to have had least 5 episodes of vertigo, with a history of migraine. This makes TIA very much less likely.

Milton S. -

A fine job! I enjoyed it.

Jess Mason -

Thanks Milton!

Jonah S., RN -

Great way to remember findings suspicious for central cause on HINTS: HINTS to INFARCT.
IN- Impulse Negative (normal HI)
FA- Fast-phase Alternating (for nystagmus)
RCT- Refocus on Cover Test (for skew deviation)

Also, important to remember to complete entire HINTS exam. For instance, the nerve entry root zone for the eighth cranial nerve is in the lateral pons. These pontine structures are supplied their circulation by the AICA about 80% of the time so an AICA stroke may knock out a unilateral eighth cranial nerve and mimic head impulse findings of a peripheral AVS. Adding hearing loss to the HINTS (what Dr. Newman-Toker calls the HINTS+) helps to uncomplicate this matter but if we just stop after an abnormal vestibulo-ocular reflex we can still miss strokes.

David S. -

To clarify, during the HINTS+ examination, is a HINTS examination consistent with peripheral vertigo (i.e. + head impulse test, as above) and positive for hearing loss considered peripheral or central vertigo? I am assuming the hearing loss with the + head impulse testing means it is peripheral, but I am not certain whether this nerve entry root zone lesion would affect hearing or not based on the comment. Thanks!

Peter Johns, M.D. -

If any of the 4 components of HINTS plus are "central" then you are HINTS plus "central". If you only relied on HINTS with an AICA stroke, you may see an abnormal HIT, and thus think that the patient is (falsely) "HINTS-peripheral". If you test for hearing loss as with HINTS plus, you will find a hearing loss with most AICA strokes, and thus the patient will be correctly identified as "HINTS plus -central". It's actually due to the fact that the AICA supplies the Labyrinthe Artery, so sensory organs of hearing and balance are both affected, leading to an abnormal HIT and hearing loss.

Paul J. V. -

This was a fantastic explanation of the approach to the dizzy patient. I listened twice today on a long drive. I plan to listen a couple of more times and check out the videos. I have one question regarding HINTS:

Talking about nystagmus, it is abnormal to have the fast component occurring bilaterally. If I'm testing a patient and:
when he looks left he has a right sided nystagmus (fast component to right), and when he looks right he has a left sided nystagmus (fast component to left), is this normal, or would this be abnormal and indicate a possible central lesion?

Jess Mason -

Hi Paul! Yes, the finding you have described is bidirectional nystagmus which is concerning for a central lesion. A peripheral lesion should only cause unidirectional nystagmus.

Dallas H. -

Great review, thank you for tackling this daunting topic!

Jonathan S. -

To add to the great comments above, I seem to remember a statement almost in passing in the episode saying that Jess sort of gives the patient a "dry run" of the head impulse test before actually assessing the result. This can give a false result. The saccade of a positive head impulse test is extinguishable, in the same way that Stuart mentions toward the end of the episode that the brain will suppress bad incoming data in a benign peripheral process. Repeated head impulse tests will induce the brain to extinguish the finding, so it is important to pay careful attention with the first head impulse test performed in each direction.

Eric S. -

Any thoughts on CTA head/neck and discharge home if normal in a patient you have a moderate level of suspicion for posterior circulation (cerebellar) etiology? You mentioned non-con CT was around 10% sensitive, any idea of sensitivity with arterial timed contrast? This would allow for reduction of admission to get the MRI in facilities that cannot accommodate MRI in the ER (if sensitivity is adequate).

Benjamin S. -

You had mentioned some links to the HINTS exam in the show notes but I wasn't able to find these. Can you direct me? Thanks, great review!!

Jess Mason -

Thanks Tracy. And also, there is a link to the video all the way at the bottom of the written summary. It's the last thing on the page called "3-Component H.I.N.T.S. Battery Video" by Dr Newman-Toker.

Tracy G. -

Hi Benjamin! The link you are referring to is actually a chart on the HINTS exam. You will find this chart on Page 3 of the written summary.

To join the conversation, you need to subscribe.

Sign up today for full access to all episodes and to join the conversation.