Is This VNG Report Worth Anything?

This week I offer up a copy of report on a patient I saw a couple of weeks ago. Of course, identifying information about the patient and the clinic that produced the report has been redacted.

This was a nice lady with a complaint of postural and gait instability, progressive over several years. She had no positional complaints, and no complaints of vertigo or lightheadedness. She simply felt unsteady and at risk of falling when she walked. In the course of the case history interview, she told me that she had a known “inner ear problem” and was tested and treated at a local pain clinic about a year earlier. She reported a history of progressive lumbar spinal stenosis.

After listening to her complaints and history, I told her that her complaints did not sound consistent with an “inner ear problem,” but were more likely related to her spinal stenosis, and got a copy of her previous “inner ear” test.

To put this in context, the local pain clinic has no neurologist, otolaryngologist or audiologist (the typical performers of “inner ear” tests), but apparently they are performing VNG exams.

Here is the untouched report of the VNG exam: but make it to the end for the conclusion of my exam.

 

VNG REPORT

Procedures: Bithermal air caloric tests, spontaneous gaze, up/down/left/right directional gaze, gaze with fixation, 30 deg. Saccades test, horizontal and vertical head rotation tests, torsion swing w/wo fixation tests, high-frequency head shake, positional tests, bi-directional Optokinetic test, and left/right Dix-Hallpike maneuver.

Findings:

Examiner Notes: The patient has a history of centrally acting medications.

Spontaneous Gaze: Excessive random eye movements and rightbeating tendencies are noted on the test.

Gaze w/ Fixation: Normal suppression during fixation.

Saccades: Latency of .383 is normal. Velocities and accuracies are normal. The patient was anticipating target movement.

Optokinetic: Abnormal optokinetic horizontal nystagmus is illustrated in the rightward direction. Normal optokinetic horizontal nystagmus is identified in the leftward direction. Possible CNS finding.

Directional Gaze: Normal. No clear nystagmus processes are identified in the up, down, left, or right gaze directions.

Horizontal/Vertical Head Rotation: Normal evoked nystagmus.

Torsion Swing: Normal suppression of evoked nystagmus. Evoked nystagmus is suppressed by approximately 70% with fixation.

High-Frequency Head Shake: Rightbeating and downbeating nystagmus are demonstrated in the tracings.

Dix-Hallpike: Excessive random eye movements and leftbeating geotrophic downbeating nystagmus are identified on the Dix-Hallpike left test. Rightbeating geotrophic downbeating nystagmus is illustrated in the Dix-Hallpike right tracings. The patient presented a classic right posterior semicircular canal BPPV response. If a diagnosis of BPPV is consistent with your medical examination, a Semont Liberatory or Canalith Repositioning Maneuver should prove successful in ameliorating the patient’s positional vertigo.

Positional Tests: Rightbeating nystagmus is visible in the supine head center tracings. Leftbeating geotrophic downbeating tendencies are present on the body left tracings. Rightbeating geotrophic nystagmus is demonstrated in the body right tracings. Findings are consistent with an uncompensated vestibulopathy of canalithiasis involving the right lateral semicircular canal which is consistent with the high frequency head shake findings.

Bithermal Calorics: Caloric irrigations produced a reduced right labyrinthine reactivity of approximately 33%.

Overall Impression:

1. The Optokinetic rightward is consistent with mild CNS dysfunction or CNS degeneration.
2. Consider additional neurological testing if there is clinical correlation to central dysfunction such as a CT or MRI of the brain.
3. BPPV involving the right posterior canal. (Epley Maneuver)
4. Consider a Semont Liberatory or Canalith Repositioning Maneuver to provide the vestibular rehabilitation necessary to ameliorate the patient’s right posterior BPPV findings.
5. Positional findings are consistent with an uncompensated vestibulopathy of canalithiasis involving the right lateral semicircular canal which is consistent with the high-frequency head shake findings.
6. If a diagnosis of uncompensated vestibulopathy in the right lateral semicircular is consistent with your medical examination, an appiani maneuver or barbecue roll maneuver should prove successful in ameliorating the patient’s positional vertigo.
7. Caloric results indicate dysfunction of the right lateral canal or its afferent neural pathways.
8. Consider vestibular rehabilitation that targets the right lateral canal.
9. All other findings are within normal limits.

Okay, there you have it. The exam I performed several months after this one 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 not necessarily a result of) her history of lumbar spinal stenosis.

For those of you familiar with vestibular testing and interpretation, you are probably already scratching your head. Who wants to point out “issues” with this report and these recommendations? Please post your observations in the comments section. I will be back next week to point out a few inconsistencies.

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.

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