Does Dizziness Cause You Diagnostic Disequilibrium?
Although most providers have developed a standardized approach for the evaluation of dizziness, the variation from one provider to the next is likely as vast as the difference in the ways patients report their symptoms.
For several reasons, including improved outcomes, utilization control, operational efficiency, and patient safety, it’s time to narrow the gap in practice variation.
Most cases of vertigo are benign and are not associated with serious pathology or likely to result in bad outcomes no matter what we do. However, the real key is to trim the diagnostic fat without becoming so diagnostically lean that you miss something important. One way, and perhaps the most common, is the shotgun approach (check all the boxes and let the tests guide you), and another is the dartboard approach (random selection of testing combinations based on gestalt). However, a rational approach to dizziness is available with a review of the evidence.
Nine months ago, I started down my evidence-based pathway, evaluating a 67-year-old female patient with new-onset dizziness. I was working at a facility that had easy access to MRI. Despite the fact that brain CT lacks sensitivity for posterior fossa pathology, it is often ordered in the evaluation of dizziness. We do so because MRI frequently isn’t available emergently for this complaint and brain imaging of some kind just seems to make sense. Well, with MRI readily available, I elected not to order the standard CT, which rarely if ever yielded any positive findings, and ordered an MRI, which ultimately was normal as well. This patient led me to challenge whether imaging is necessary at all in patients with dizziness, whether CT has any utility, and in which patients imaging should be obtained. Three studies answered these questions for me, taking care of my diagnostic disequilibrium.
In 2012, Chase et al from Beth Israel Deaconess Medical Center in Boston published a study to determine what clinical factors were associated with stroke in vertiginous patients.1 MRIs of the brain were obtained during the ED visit or within two weeks. Of the 131 patients, 12 (9.2 percent) experienced a cerebellar or brainstem stroke (posterior fossa). CTs were negative in all five stroke cases in which one was performed. The complaint of gait instability and subtle neurological findings were associated with stroke, with odds ratios (ORs) of 9.3 and 8.7, respectively. Of particular note was that nystagmus was only present in a third of those with stroke and in a fifth of those without stroke.