Why is this VNG exam worthless?

It may be helpful to go back to last week’s blog and print out a copy so that you can follow along with today’s commentary.

Let me tell you what I know about last week’s “interesting” VNG report. The exam was performed in December 2012. The report was faxed from an out-of-state medical supply company’s FAX machine in September 2013. We called the pain clinic where the patient was seen and asked for the hard copy of the VNG exam tracings, but were told that all they had was the dictated letter.

Let me tell you what I think about the same report. It appears that the report was dictated by someone off site who had never spoken to, examined, or possibly even been in the same state as the lady undergoing the examination. Is this good patient care? Is this legal? Is this an example of the business of offering “profit centers” to primary-care practices, tempting them to perform exams they know little to nothing about? Let me rant:

Is this good patient care? No. It’s terrible patient care.

Where do I begin? First, vestibular tests are only helpful when placed in the context of the patient’s medical history and complaints. It is clear from the report that the person interpreting the tracings was not aware of the patient’s complaints. Let me point out why that is so apparent.

The report notes right-beating spontaneous nystagmus, but nothing in gaze right or left. That just doesn’t happen. So, it is most likely there was no spontaneous nystagmus and the interpreter was observing artifact or, as they describe it, “excessive random eye movements.”

Torsion swing:
The torsion swing test has not been part of the test battery in probably 25 to 35 years, and based on the findings, the examiner wasn’t doing a torsion swing test anyway. It looks as if the person was measuring fixation suppression of vestibular nystagmus. This is useful information, but it is usually measured as part of the caloric exam. There is no billable code for assessment of fixation suppression, but I have a strong suspicion that this was billed incorrectly as a rotary chair test.

The examiner reports the same geotropic rotary nystagmus in both the DH left and right, but decides this means the patient has Posterior canal BPPV on the right. A “classic right posterior semicircular canal BPPV response” would be rotary and up beating nystagmus (not down beating, as described). I mentioned earlier that this patient never had any complaints of positional vertigo, or vertigo of any type.

The examiner decides that nystagmus noted in multiple planes in various positions represents an uncompensated vestibulopathy in the right lateral (horizontal) canal, and later recommends horizontal canal repositioning for this uncompensated vestibulopathy. This is tough to comment on. Unless you are performing a test that measures the gain of the vestibular ocular reflex such as Rotational Chair or Active Head Rotation, or doing functional tests such as Platform Posturography, it is difficult to comment on a patient’s state of vestibular compensation. Canalith repositioning (here described as the Appiani or Barbecue roll) does not promote central compensation. Canalith Repositioning is a treatment for BPPV, but not for uncompensated vestibulopathy.

So, this lady who had no complaints of positional vertigo is diagnosed with two different forms of BPPV at the same time (right posterior and lateral canal), and a right caloric weakness, which was interpreted as uncompensated despite an absence of any supporting information. Her complaint of postural and gait instability remained untested and unaddressed.

Remember from last week’s blog, my exam showed normal vestibular function, no gaze, spontaneous or positional nystagmus or complaints, normal rotary chair, and normal calorics. The only abnormality was a noted surface dependence pattern on posturography, consistent with (but necessarily a result of) her history of lumbar spinal stenosis.

Is this legal? Honestly, I don’t know. It would seem to me that, minimally, the clinic should be able to produce the actual eye tracings, and the name of the person doing this analysis and dictating the report should be included.

Is this an example of people who don’t know what they are doing, but are doing it anyway to make a few dollars? I think so!

About Alan Desmond

Dr. Alan Desmond is the director of the Balance Disorders Program at Wake Forest Baptist Health Center, and holds an adjunct assistant professor faculty position at the Wake Forest School of Medicine. In 2015, he received the Presidents Award from the American Academy of Audiology.