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ACEP Now: Vol 34 – No 03 – March 2015Also in 2012, Navi et al published a paper reviewing the records of 907 patients presenting to the University of California, San Francisco emergency department between 2007 and 2009. The patients presented with the complaint of dizziness, vertigo, or imbalance for a mean duration of one day.
There was substantial variation in the diagnostic evaluations performed. Laboratory diagnostics were ordered in 72 percent, ECGs were performed on 68 percent, neuroimaging in 35 percent, and neurology consultation in 20 percent of the patients. Serious neurological disease was identified in 5 percent, with stroke being the most common (diagnosed in 3 percent). The independent predictors for serious neurological disease were:
- Focal neurological abnormalities: OR 5.9
- 60 years of age or older: OR 5.7
- Imbalance: OR 5.9
- Isolated dizziness: OR 0.20
Patients older than 60 experiencing imbalance with an identifiable focal neurological abnormality were the most likely to experience serious neurological disease. However, even more helpful is the OR of 0.20 when the patient experienced isolated dizziness. Patients experiencing isolated dizziness and no other symptoms or neurological abnormalities were 80 percent less likely to be experiencing a serious neurological cause.
Finally, in September 2013, Ahsan et al evaluated the costs and utility of neuroimaging of ED patients complaining of dizziness. A total of 1,681 patients seen at Henry Ford Hospital’s ED in Detroit from 2008 to 2011 were included. CTs were performed 48 percent of the time; MRIs, only 5 percent of the time. Overall, 0.74 percent of the CTs were abnormal (6/810), as were 12 percent of the MRIs (11/90). The cost associated with identifying one abnormal CT was $164,700 and $22,058 for a positive MRI. In addition, all patients with a positive CT or MRI had a headache, neurological findings on examination, or ophthalmological complaints along with their dizziness.
Dr. Klauer is the chief medical officer–emergency medicine and chief risk officer for TeamHealth as well as the executive director of the TeamHealth Patient Safety Organization. He is an assistant clinical professor at Michigan State University College of Osteopathic Medicine, speaker of the ACEP Council, and medical editor-in-chief of ACEP Now.
References
- Chase M, Joyce NR, Carney E, et al. ED patients with vertigo: can we identify clinical factors associated with acute stroke? Am J Emerg Med. 2012;30:587.
- Navi BB, Kamel H, Shah MP, et al. Rate and predictors of serious neurologic causes of dizziness in the emergency department. Mayo Clin Proc. 2012;87:1080.
- Ahsan SF, Syamal MN, Yaremchuk K, et al. The costs and utility of imaging in evaluating dizzy patients in the emergency room. Laryngoscope. 2013;123:2250.
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4 Responses to “Myths in Emergency Medicine: Diagnostic Imaging for Dizziness”
March 22, 2015
Alan J. Sorkey MDGood to know that CT scan are worthless in these cases. I will be sure to send a copy of this article to the patient I recently saw with dizziness and an acute brainstem infarct on CT scan. He had just been sent home from a stroke center with no CT scan.
How does this balance with the malpractice payout for missed stroke diagnosis? How about factoring in the time spent in responding to patient complaints and to peer review.
Take-home point: CT is not worthless in the evaluation of dizziness. It is what the patient expects, it is what the peer review panel (in retrospect) will expect. A normal CT makes for a happy patient and protects the doctor, very worthwhile in my opinion.
March 22, 2015
Chuck PilcherSince a large percentage of posterior fossa strokes are from vertebral artery dissections, what is the value of CT Angiograms?
March 22, 2015
Jonathan EdlowAlthough it is good to see an emphasis on the diagnosis of the dizzy patient, Dr. Klauer is perpetuating another myth – that “nystagmus is unreliable”. He is right that the mere presence of any kind of nystagmus does not help to differentiate peripheral from central causes of the acute vestibular syndrome. However that is akin to saying that “the presence of EKG changes is unreliable” for diagnosing an ACS. All abnormalities are not created equal; a flat T wave does not have the same significance as ST segment elevation.
It’s the same with nystagmus. Its mere presence does not always help – but the KIND of nystagmus is VERY helpful to the diagnostician in sorting out the cause of dizziness. Some of the source for this comes from the Chase article but this article (I was an author) only described presence or absence of nystagmus (unfortunately, this is the way more EPs chart it), but it’s not meaningful.
In a patient with ongoing dizziness, one should be hesitant to diagnose vestibular neuritis or labyrinthitis if there is NO nystagmus. The nystagmus is “direction-fixed” – i.e., the fast component always beats to the same side no matter what direction the patients is looking in.
On the other hand, direction-changing nystagmus is this setting means that there is a central process (probably stroke). So does torsional or vertical nystagmus. Patients with peripheral causes will have direction-fixed horizontal nystagmus.
In positional (episodic) dizziness, these rules shift. Emergency physicians must learn some of the details about nystagmus as it can really help us to make a confident diagnosis.
The presence/absence of nystagmus but more importantly, its quality, is very helpful in making a specific diagnosis in dizzy patients.
April 23, 2015
strength in numbers: dizziness | DAILYEM[…] Cribbed from this March ACEP Now article: […]