Are Vestibular Exams as Effective as Electronystagmography?

The examination included spontaneous, positional, and vestibular-induced eye movements, while a laboratory-based ENG used surface electrodes and standard protocol to acquire and analyze oculomotor and vestibular eye movements.

The audiologist was blinded to the physician’s a priori prediction of ENG results.

Vestibular exam and ENG results were correlated to determine the percentage of correctly predicted results.

The study showed 100% predictive sensitivity of vestibular exam for spontaneous, post-head shake, and nonparoxysmal positional nystagmus. The vestibular exam sensitivity for predicting unilateral vestibular hypofunction was reported at 95% compared with caloric results.

Dr. Hamid concluded that the study determined that office vestibular examination is highly sensitive in predicting ENG test results in 95% of vestibular patients. He further concluded that physicians can rely with confidence on office vestibular examination when ENG is not available.

The Message

Dr. Hamid said the takeaway message from this study is not that ENG is no longer a viable method for screening dizzy patients-far from it. Instead, the intention was that ENG, like other tests, is a tool to be used in conjunction with the knowledge and expertise of each individual physician.

Nothing in this prospective study suggests we cannot or should not use ENG on our patients, Dr. Hamid said. A vestibular exam is not a replacement for the ENG, but the ENG should be used to complement the examination findings.

A physician properly versed in how the vestibular system works, and who does not have access to an ENG, should use a vestibular exam as an outline to glean enough information to indicate if an ENG is needed, Dr. Hamid said.

Doctors in rural areas many times do not get access to tools like an ENG, but they still need to get an idea of what is going on with the patient, Dr. Hamid said. In fact, vestibular examination can be video recorded for objective documentation of findings. It has to be emphasized that the knowledge and training of the examining physician regarding the vestibular system is very critical.

Dr. Hamid added that it is encouraging to see that several otolaryngology programs are now including advanced vestibular training in their curricula.

However, Dr. Gianoli said he is concerned with how the vestibular system expertise of the average otolaryngologist stacks up against a leading-edge dizziness expert of Dr. Hamid’s caliber.

You just can’t say that a neurotologist who does nothing but ‘dizzy work’ will have the same results as a general ENT, Dr. Gianoli said. It is one thing for someone with as much experience treating dizzy patients as Dr. Hamid to be able to glean the proper diagnosis from an office exam, but to expect a general ENT to replicate those results is a significant leap.