A primary diagnosis of BPPV was made due to the positioning nature of PB's 'wobble' symptoms, the brief latency of these symptoms and the positive Dix-Hallpike test
demonstrating a positional upbeat clockwise torsional nystagmus.
The criterion for a vestibular anomaly is either an abnormal result on the Dix-Hallpike test
or an abnormal result on at least two of the other three tests (rotational chair test, posturography, or ENG/VNG).
The presence of a burst of rotary nystagmus, which is counterclockwise at the right side and clockwise at the left side in the Dix-Hallpike test
and subsides within seconds, indicated a typical posterior semicircular canal BPPV.
Five months following her first visit, a Dix-Hallpike test
revealed that nystagmus occurred only when her head was down and to the left.
Positional vertigo and nystagmus demonstrated on the Dix-Hallpike test that does not fit the characteristics of BPPV raises the suspicion of other diseases.
However, the results of her positional testing were abnormal, as the Dix-Hallpike test provoked a marked rotary nystagmus bilaterally.
Repeated Dix-Hallpike tests
were positive for left sided posterior semicircular canal BPPV despite multiple particle repositioning procedures over a period of three years.