Monthly Archives: August 2017

Predictors of Central Dizziness

I’m rotating through a community emergency department this month, in which it seems like 40% of the patients I’m seeing have dizziness as some element of their constellation of chief complaints. This is one of the most difficult chief complaints to evaluate in emergency medicine — not only because people use the term “dizziness” to describe a multitude of subjective experiences, e.g. vertigo, syncope/presyncope, generalized weakness, anxiety, ataxia, or any sort of disturbance in mentation. Add in the barriers to effective communication that can accompany elder patients visiting an ED, such as language barriers + hearing/vision issues that accompany aging (imagine a translator on a video phone screaming at a patient who is extremely hard of hearing) and this becomes a tricky subject indeed.

To that end, I reviewed a paper published by a Korean group evaluating dizzy patients in their emergency department: Characteristics of central lesions in patients with dizziness determined by diffusion MRI in the emergency department, by Lee et al.

This was a retrospective review of 902 patients presenting to a single ED with a chief complaint of dizziness over six months. They looked closely at 645 patients (!) who recieved MRI imaging as part of their workup, which showed 23 patients (3.6%) having strokes, the majority in the posterior circulation. The authors then examined the characteristics that best predicted the presence of a central lesion.

Their findings? Predictably, advancing age brought with it a higher likelihood of central etiologies: the rate of central lesions on DWI was 3.9% and 3.5% in patients in their 50s and 60s respectively; 7.4% in 70s and 16.7% in their 80s! Hypertension was more common in patients with strokes (69% versus 36%). Atrial fibrillation was more common. 77% of patients with a central cause reported a more vague non-whirling dizziness compared to 40% in patients without central lesions. Other associated neurologic symptoms were present in about 46% of patients with a central cause, compared to only 3% in those who were MR-negative.

So while this study had all the drawbacks of most retrospective, single-center publications, and may not generalize exactly to the populations I work with, I felt it was useful in terms of giving me at least *some* numbers to use to estimate what proportion of these patients are hiding badness. I will have a much lower threshold to MRI patients who are in their 70s-80s, those with AF who aren’t anticoagulated (though the sensation of palpitations or the diminished cardiac output can contribute to the sensation of dizziness as well), or those who report a “vague non-whirling” sense of dizziness. That last point stands in contrast to what I’ve read in other studies that suggested that the character of dizziness was *not* useful, so that was interesting. When this study was reviewed on EMRAP another thing that Sanjay and Mike mentioned was that older patients often have difficulties cooperating with the exam, accurately reporting/describing their symptoms, and that our threshold for obtaining further diagnostic imaging in these patients should be lower.

More on dizziness to come soon, I’m sure.

References

Lee DH1, Kim WY2, Shim BS3, Kim TS4, Ahn JH5, Chung JW5, Yoon TH5, Park HJ5. Characteristics of central lesions in patients with dizziness determined by diffusion MRI in the emergency department. Emerg Med J. 2014 Aug;31(8):641-4. PMID: 23722117. [PubMed] [Read by QxMD]