Make the Diagnosis: Vertigo
Once the medical history confirms vertigo in a patient with dizziness, most affected patients will have a peripheral vestibular disorder (40%). The prior probability of benign positional vertigo among dizzy patients is 10%.
Population for Whom Vertigo Should Be Considered
Detecting the Likelihood of Vertigo
The medical history identifies the patient with true vertigo, whereas the clinical examination results identify patients with benign positional vertigo. The responses to the maneuvers are not screening tests with an associated sensitivity and specificity because they define the diagnosis of benign positional vertigo.
The diagnosis requires direct observation of eye movements during positional testing in a patient with no focal neurologic findings or central nervous system disease. Prospective clinical studies might put more weight on the observations by a specialist, but no comparison studies between generalist physicians and specialist physicians have evaluated the accuracy of generalist clinicians.
Original Article: Does This Dizzy Patient Have a Serious Form of Vertigo?
A 52-year-old woman was admitted to the hospital because of nausea, a constant spinning sensation, and vomiting of 24 hours’ duration. Any movement of her head made these symptoms worse. On examination, she had bilateral horizontal spontaneous nystagmus. Two days later, after symptomatic improvement, she was discharged. At follow-up 2 weeks later, her symptoms and nystagmus had completely resolved.
A 70-year-old woman had a 4-month history of an intermittent whirling sensation when turning her head and especially when rolling over in bed. On examination, a left-side-down head-hanging maneuver elicited rotatory nystagmus, with the fast component to the left ear (Figure 53-1). There was a latency of about 3 seconds before the onset of nystagmus, which lasted approximately 10 seconds.
How to Test for Positional Nystagmus
The Dix-Hallpike maneuver for positional vertigo is performed by the examiner, who stands at the head of the bed. As the patient is supported and lowered into a position whereby his or her rotated and extended head hangs off the end of the examining table, the examiner observes for nystagmus. In this view, the patient's head has been rotated to the left and expresses nystagmus with a slow response to the right and a rapid response the left. Repeating the maneuver with the head rotated in the opposite direction would reverse the direction of the nystagmus. A maneuver (with positive indication) will reproduce the patient's symptoms.