BPPV (Benign Paroxysmal Positional Vertigo) is the most common cause of vertigo and dizziness complaints. It is generally easily treated once identified, as long as it happens to affect the posterior canal. In fact, it seems that many people are self diagnosing and going to the internet for home treatment instructions. Many physicians are sending people home with exercises for suspected BPPV, assuming that posterior canal BPPV is the source of the patient’s complaint, most often without having performed any exam for BPPV.
A few years ago, I did a post here regarding published statistics associated with BPPV. Among other disturbing statistics, I posted this: “ Despite the high incidence of BPPV, testing for positional vertigo is still rare (<10%) in the primary care setting (Polensek, 2008).” In a large study regarding management of dizzy patients seen in the Emergency Department, only 4% of patients complaining of dizziness underwent positional testing that may identify BPPV. Frankly, given the high incidence of BPPV in the general population, and the over 90% preponderance of posterior canal involvement, I can understand the reasoning behind this. Working at a large university medical center/teaching hospital, we tend to see the patients that do not respond positively to this approach, so our viewpoint may be skewed. We see many patients with less easily treated variations of BPPV, and some with positional vertigo due to worrisome brain and brainstem pathology. Basically, if they got better doing the home exercises, they don’t make an appointment with us.
BPPV can occur in any of the three semi-circular canals, and treatment differs depending on the involved canal. The offending canal can be identified with a positive positional test, based on the pattern of eye movements (nystagmus) seen during the episode of vertigo. Always keep in mind that a negative test does not rule out BPPV as the source of the patient’s complaint. As noted above, occasionally we see nystagmus pointing to dysfunction in the brainstem (of course our suspicions can only be confirmed through imaging of the brain and neurology examination).
Where am I going with all this? The Dix-Hallpike exam is a quick, simple, effective test to identify nystagmus that can help the examiner determine the cause of the vertigo complaint, yet it seems that it is still not part of the routine exam for dizziness. My next post will review a recently published study examining this issue, and offering some suggestions to hopefully increase the percentage of dizzy patients being offered positional testing.