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Interview with Neil Shepard, Ph.D., Member of the ASHA Executive Board

Neil T. Shepard, PhD

November 21, 2005

Topic: Vestibular Issues, Professional Training, Dix-Hallpike, BPPV and Meniere's
Neil Shepard, Ph.D., Member of the ASHA Executive Board, ASHA Vice President for Quality of Service in Audiology. Boy's Town National Research Hospital, Omaha, Nebraska. Professor, Department of Special Education and Communication Disorders, University of Nebraska at Lincoln.

Beck: Good morning Neil. Thanks for your time today.

Shepard: Hi Doug.

Beck: Neil, would you please tell give me a brief overview of your professional education?

Shepard: I earned my master's degree from MIT in electrical and biomedical engineering in 1974. After that, I went to the University of Iowa where I examined compound action potential tuning curves. I finished my doctorate in clinical Audiology and clinical electrophysiology in 1979.

Beck: Neil, I know you have a wealth of knowledge in the diagnosis, treatment and management of the dizzy patient -- and I'd like to focus on that today. What are the most important components of a modern balance lab?

Shepard: The single most important component of a modern balance lab is the personnel, i.e., the audiologist that performs and interprets the tests, the other professionals such as physical therapists, neurotologists, neurologists, and psychiatrists. If they integrate and function as a team the patient is very well served.

Beck: How does an audiologist acquire vestibular-specific training?

Shepard: That's a great question. It varies. There are courses taught here and there, but they are not standardized, and it is admittedly spotty. The vestibular curriculum varies across university training programs from "lacking" to excellent, so it's a real challenge. Often, vestibular training is accomplished at the post-graduate level.

Beck: I know the same dilemma applies to intraoperative monitoring. Training varies across location and practice types. In the final analysis, it's often the individual who must seek out appropriate training from a mentor, as the profession's standard training and educational model doesn't include all the subspecialty areas we might practice in.

Shepard: I agree. Intraoperative monitoring (IOM) is in a similar situation, and in a nutshell, the real problem is the quantity of professionals specializing in IOM and balance and dizziness is quite small relatively speaking, and all training programs cannot offer comprehensive and appropriate academic and clinical training. It's just not financially viable.

Beck: Not to get too political...but I've always thought that if we had fewer graduate programs, with more students in each program, I'll bet we could do a better job thoroughly and comprehensively training clinicians in all areas within our scope of practice.

Shepard: Yes, that may be one way to solve the problem. However, I have also traveled to various programs across the country, and offered a five day program in which I give the students the equivalent of a three credit hour college is intense and rigorous. The students get a solid introduction, and then the students could attend formal balance disorder clinics for their "practicum" in balance and dizziness and be able to benefit from that experience. In some situations, faculty members would attend the class and develop their own interests, and then that faculty member would provide the next course on the same it opens a few doors, and is one means to deliver subspecialty content areas to programs that do not have faculty with depth in a particular area.

Beck: I like that idea, too. If there is enough interest, and if the programs can support the project, it makes sense. OK, Neil, if you don't mind, I'd like to change topics and ask you a few unrelated balance questions...sort of a "miscellaneous ask-the-expert-question-and-answer" session, based on some of the recent queries I've received. Is that OK?

Shepard: Sure.

Beck: First of all...In the normal ENG battery, do you recommend the Dix-Hallpike?

Shepard: Yes. I do it all the time. But's a clinical test, and you really must watch the eyes in real time, related to the head cannot just read the recordings later and make sense of it.

Beck: What about cautions to the patient before performing the Dix-Hallpike?

Shepard: Cautions are important, but they can be overdone! If the patient is unable to participate in the Dix-Hallpike, there are alternatives such as the "side lying test" which can be offered and performed if and when needed. For example, if the patient has a lower back, cervical spine or abdominal injury. However, in an otherwise healthy patient, the Dix-Hallpike is safe and useful, as long as you can get the patient's ear at a level below the shoulder with an appropriate relationship to gravity. This can be accomplished without hyper-extending the neck, as long as you tilt the head of the bed down. So yes, one needs to be cautious and really understand what they're doing and why, and then the test can be performed safely or modified as needed.

Beck: What about Frenzel often do you use them?

Shepard: I use them frequently. The standard, traditional lenses are fine for the Dix-Hallpike. However, if given a choice, I prefer the electronic goggles, such as the infra-red with a video recorder, as that allows me to review the recordings later if I wasn't sure what I was viewing the first time, and also, the electronic goggles magnify the eye and the eye movement, and that allows me to be more sensitive to eye movement. However, if you do not have such equipment, you can still perform the testing of the Dix-Hallpike as the type of nystagmus in the majority of patients with BPPV will not be suppressed with fixation. The Frenzel lenses, mechanical or electronic, add to your ability to see the eye, but the clinical test can be easily performed with good results without them.

Beck: What is the most common vestibular diagnosis?

Shepard: Benign paroxysmal positional vertigo (BPPV) is probably some 20 to 50 percent of all vestibular diagnosis. The key to the diagnosis is the eye movement, and it should consist of a torsional component together with a vertical component representing the traditional anterior-posterior canal aspect, and if you have that, together with the symptom complex, you probably have BPPV.

Beck: And by the "symptom complex" you mean the patient describes it as "spinning," it lasts 10 to 30 seconds, it has rotary nystagmus, it fatigues with repetition, and is usually unilateral, and the rest of the ENG battery - including calorics -- is essentially normal?

Shepard: Yes, those are some of the general characteristic of BPPV. However, the ENG does not have to be normal. In fact, it is more common to have BPPV as part of a more encompassing diagnosis then as a pure entity by itself. In many of those cases there will be other findings from ENG or other evaluation tools that implicate other potential abnormalities within the labyrinthine system. Additionally, the symptoms and nystagmus can be very short (1-2 seconds) up to 30-40 seconds in rare cases with widely varying degrees of intensity of nystagmus and symptoms.

Beck: Do you believe the cupulolithiasis and canalithiasis theories, which state that otoconia essentially free-float and then land in the wrong location, producing the symptoms of BPPV?

Shepard: Yes. I think the theories have been reasonably well supported through anatomical studies, the geometry of the inner ear, and by the repositioning treatment successes, which depend on the debris being ushered back to their original location! The concept that otoconia come loose from the matrix that holds them in the otolith organs is reasonable and substantiated by the fact that we produce and absorb these crystals throughout life.

Beck: And the repositioning maneuvers are typically the Epley or the Semont?

Shepard: Yes. And the success achieved by these techniques is better than 90 percent, which is outstanding.

Beck: I have often wondered why it's not 100 percent, and I suppose sometimes the diagnosis is wrong, sometimes the repositioning is not as good as it might be, and likely, sometimes it just doesn't work based on the particular size and shape of the otoconia or perhaps the cochlea...and who knows what else might be a factor!

Shepard: Well, if the first repositioning doesn't work, and it usually does in 85 to 90 percent of all cases, by the end of the 2nd attempt, the results are successful some 95 percent of the time.

Beck: Changing subjects again....What about vestibular rehab success for Meniere's patients?

Shepard: If the particular Meniere's patient is only having spontaneous events, with no residual symptoms in between events, there is no role for vestibular rehab. However, if the patient has residual symptoms between Meniere's attacks, that is, they have problems with balance and motion provoked symptoms between attacks, then sometimes, vestibular rehab can help and can be quite effective to control the residual symptoms between attacks.

Beck: Neil, thanks for your time. I appreciate your time and thoughts on these issues.

Shepard: Happy to help, Doug.

Recommended Texts for a general overview of the topics for the beginner to those with more knowledge in the areas of Balance and Dizziness:

Baloh & Halmagyi. Disorders of the Vestibular System. Oxford University Press, New York, 1996

Baloh & Honrubia. Clincial Neurophysiology of the Vestibular System. Edition 2. F.A. Davis Company, 1990

Bronstein, Brandt & Woolacott. Clinical Disorders of Balance and Gait. Oxford University Press & Arnold, 1996.

Furman & Cass. Balance Disorders: A Case-Study Approach. F.A. Davis Company, 1996.

Goebel JA, ed. (2000) Practical management of the dizzy patient. Philadelphia: Lippincott Williams & Wilkins.

Harada, Y. The Vestibular Organs - SEM atlas of the inner ear. Kugler & Ghedini Publications, Amsterdam, Berkeley, Milano, 1998.

Herdman, S.J. Vestibular Rehabilitation. 2nd ed. F.A. Davis Co, 1999.

Highstein SM, Fay RR, Popper AN (2004) The Vestibular System. New York: Springer.

Jacobson, Newman & Kartush. Handbook of Balance Function Testing. Mosby Year Book, Inc., 1993. (Now published by Singular Publishing Group, 1997)

Leigh & Zee. The Neurology of Eye Movements. Edition 3. F.A. Davis Company, 1999.

Poe, D (ed). The consumer handbook on Dizziness and Vertigo. Auricle ink Publishers, AZ, 2005 (for those without specific training in the area)

Shepard, N.T. & Solomon, D. Practical Issues in the Management of the Dizzy and Balance Disorder Patient The Otolaryngologic Clinics of North America, WB Saunders Co, Vol 33, # 3, June 2000.

Shepard, N.T. & Telian, S. A: Practical Management of the Balance Disorder Patient. Singular Publishing Group, Inc., 1996.

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Neil T. Shepard, PhD

Professor of Audiology in the department of Special Education and Communications Disorders, University of Nebraska – Lincoln

Dr. Shepard has worked in a clinical capacity between otolaryngology and neurology performing assessments and designing non-medical treatments for patients with dizziness and imbalance for the past 24 years. He has developed three fully integrated balance labs at Ford Hospital, University of Michigan and most recently at University of Pennsylvania.

Dr. Shepard is Professor of Audiology in the department of Special Education and Communications Disorders, University of Nebraska – Lincoln and a member of the faculty at the Boys Town Research Institute in Omaha.  He received his undergraduate and masters training in Electrical and Biomedical Engineering from University of Kentucky and Massachusetts Institute of Technology.  He completed his PhD in auditory electrophysiology and clinical audiology from the University of Iowa in 1979.  He has specialized in clinical electrophysiology for both the auditory and vestibular systems.  Activity over the last 24 years has concentrated on the clinical assessment and rehabilitation of balance disorder patients and clinical research endeavors related to both assessment and rehabilitation. I have no affiliations

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