Using Provocative Tests to Diagnose Psychogenic Non-Epileptic Seizures
Two Points of View: Medical and Ethical
The tests to which Dr. Gates was referring are described by one of our medical experts, Selim Benbadis, MD, who is from the University of South Florida and Tampa General Hospital. He is a proponent of provocative tests, although he points out that a different method is currently used, which should be less objectionable. Nevertheless, Jeffrey H. Burack, MD, now in private practice and Co-Medical Director of the East Bay AIDS Center in Berkeley, CA questions the ethics of such testing.
We asked both Dr. Benbadis and Dr. Burack to give us an update on this topic and to discuss their opinions with regard to the use of provocative tests for the diagnosis of psychogenic non-epileptic seizures.
COMMENTS OF EXPERTS
Dr. Benbadis is a French citizen, born in Paris. He obtained his MD at the University of Nice (Nice, France), where he completed a residency in Family Medicine. He then moved to the United States and completed his neurology residency at the Cleveland Clinic Foundation where he stayed an additional two years to complete a fellowship in epilepsy, EEG, and sleep medicine. He is board-certified in neurology, epilepsy & clinical neurophysiology, and sleep medicine.
Dr. Benbadis is currently Professor of Neurology in the departments of Neurology and Neurosurgery at the University of South Florida. He is Director of the University of South Florida /Tampa General Hospital Comprehensive Epilepsy Program. His interests are in the diagnosis and management of difficult-to-control epilepsy, and he has authored over 90 articles and book chapters.
Dr. Burack was born in Montreal, Canada. After completing his residency in Primary Care Internal Medicine at the University of California, San Francisco in 1991, Dr. Burack worked as a clinical and research faculty member in UCSF’s AIDS Program at the San Francisco General Hospital. He pursued additional training in biomedical ethics and general internal medicine as a National Research Service Award Fellow at the University of Washington, and was awarded the Mack Lipkin Sr. Research Award by the Society of General Internal Medicine. In 1996 he was jointly appointed as Associate Clinical Professor of Bioethics and Medical Humanities at the UC Berkeley School of Public Health and as Associate Clinical Professor of Medicine at UCSF. Dr. Burack is Co-Medical Director of the East Bay AIDS Center in Berkeley, CA, providing comprehensive medical care to a diverse population of patients with HIV/AIDS
What was the initial opposition to the use of provocative tests to diagnose PNES?
Dr. Benbadis: In the old days we used an intravenous (IV) placebo and this presented the element of deception. You had to induce a seizure, even though patients were given a placebo with a saline solution. Because of the element of deception, and because we told patients that they were getting a drug that could induce a seizure, some people objected.
Dr. Burack: What makes a practice deceptive is when we undertake to create a false belief in someone else. By giving the patient IV saline you are hoping the patient will come to believe that something is happening that isn’t. Your intent is that the patient will believe that he or she is getting an active drug that causes seizures. By not saying words that aren’t true you may not actually be lying -- according to a literal definition of lying – but your intent is to deceive by not sharing the truth.
What is the procedure that is used today?
Dr. Benbadis: Today we use hyperventilation, photic stimulation, and verbal suggestion – with the same yield; that is, we can trigger a seizure using these methods as often as we were able to by using the IV saline method.Dr. Burack: The specifics are not as important as the intention, and this is where I still disagree. Is it deceptive or not? Dr. Gates’ opinion was that it is not typically necessary to do deceptive provocative testing. However, I don’t think he would have objected to using photic stimulation or hyperventilation, or other measures, that can provoke seizures, per se.
How do you weigh the benefits of the procedure and ethical considerations?
Dr. Benbadis: The benefits strongly outweigh ethical concerns. It is extremely useful for a variety of reasons. Oftentimes you cannot record seizures spontaneously. You can have a patient in the hospital for several days and nights and nothing will happen. So when we do an activation and record information that gives us a clear diagnosis, it is beneficial. With a diagnosis we have the enormous advantage in that we can now provide appropriate treatment. Basically those who object to this actually are concerned with the diagnosis of psychogenic episodes – it is the label.
It is a difficult phenomenon and one that makes many people uncomfortable. So they may record an episode on video with no associated change on EEG. They conclude that the episode is not epileptic, but they fall short of saying it is psychogenic.
Dr. Burack: Just arriving at a diagnosis does not guarantee clinical benefit. The test has to settle a genuine clinical question, and lead to a change in therapeutic approach that ends by benefiting the patient. With PNES, it’s not clear any of this typically happens. Some patients may have both PNES and epilepsy, so establishing a PNES diagnosis doesn’t even spare them the risks of antiepileptic medications. And if a test is deceptive, it has to not only promise benefit, but do so significantly more than non-deceptive alternatives would. It is hard for us to understand conversion disorders, but PNES is a conversion disorder. And patients don't always want to hear that “either you have epilepsy or some bizarre psychiatric diagnosis.”
What do you see as the greatest advantage and value of these procedures?
Dr. Benbadis: It helps us to diagnose people whom you can otherwise not diagnose even though you might keep them in the hospital for 5 or 6 days. Without it, you may get no information at all. So this makes it very cost effective.
You have to be careful to confirm that what the patient is having at home and in the clinical setting are the same.
As we published, it is so cost effective and the yield is so good as an outpatient that it obviates the need for inpatient care.
Dr. Burack: When we talk about advantages and benefits, we need to ask benefits to whom – the patient or third party payers? You can speed things up with a provocative procedure and reduce costs, but are you then harming the patient to please the payer?
We need to ask whether a test is truly in the patient’s best interest, and whether we are violating ethical principles in performing it. If a diagnosis is made through deception it is tempting to say that it is in the patient’s best interest. It’s certainly difficult to balance ethical harms against clinical benefits. But if there is ethical risk, it’s important at a minimum to take a hard look at whether and to what degree patients really benefit, and whether less deceptive alternatives exist.
How do you answer critics of the test?
Dr. Benbadis: Like any other procedure, it has to be used and interpreted correctly, knowing its limitations. People who are unfamiliar with it say it produces “false positives.” This is completely inaccurate. When we trigger a seizure, we have the EEG so that we know we have just recorded it. They say it is dangerous because you record an episode that the patient does not necessarily have at home. We are well aware of this, and one has to be careful to confirm that what was recorded was similar to the habitual episodes.
Dr. Burack: Tests should only be performed if they add information that is genuinely helpful to the patient. Deceptive tests should be performed, if ever, only if the need is urgent and there is no alternative. Is the patient in immediate danger? Does the test change the way you act therapeutically? Can you offer something beneficial as a result? With a PNES diagnosis, this isn’t clear. Many patients continue to have seizures and do poorly, even after being diagnosed. And even the supposed benefit of stopping epilepsy drugs doesn’t always happen. If you can’t be certain that the patient isn’t also having occasional epileptic seizures, and they stay on drugs anyway, there is no marginal gain to having done the test.
Do you feel that provocative testing could undermine the patient-physician partnership?
Dr. Benbadis: It might, and I agree with the theoretical/philosophical reservations mentioned here. But weigh this against carrying a wrong diagnosis of epilepsy for years. Currently, the average patients with psychogenic non-epileptic episodes carries the wrong diagnosis for 7-10 years, ingesting antiepileptic drugs that do not help, and not addressing the underlying psychological causes.
Dr. Burack: There is certainly risk to the patient-physician partnership. Just imagine performing such a test on your mother. How would you explain afterward what you had done, and why? If doing such a test on your mother would raise qualms for you, then that ought to be a red flag. Even if it gets you a proper diagnosis the doing of the test may undermine future therapy, especially if the patient feels betrayed. He or she might become less trusting of medical personnel, and less likely to follow up with necessary care. Imagine also the public reaction to the news that physicians carry out this type of test on unwitting patients. Finally, we have to think of the physician’s professional integrity: Is this the sort of thing we should be doing?
For more information: Psychogenic (Non-Epileptic) Seizures: A Guide for Patients & Families (PDF)
Interviews by Rita Watson, MPH
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