What's Wrong With EEG Interpretation

Andrew N. Wilner, MD: Welcome to Medscape. I'm Dr Andrew Wilner, reporting on the 75th annual American Epilepsy Society meeting.

With me today is my old friend and colleague, Dr Selim Benbadis, professor of neurology and director of the Comprehensive Epilepsy Center at the University of South Florida in Tampa, Florida. Welcome, Selim.

Selim Benbadis, MD: Thank you, Andrew.

Wilner: You led a special interest group at this year's meeting on the persistent problem of EEG overinterpretation. How common is it?

Benbadis: It's very common. And you're right to say it's a persistent problem, because you, me, and others have been talking about this for many, many years, and yet it doesn't go away.

As you know, epilepsy centers have the same experience in that about 30% of patients that come for intractable seizures turn out to not have seizures. Part, if not all, of the reason they've been misdiagnosed as having epilepsy is because of an overread EEG.

Wilner:I read EEGs pretty much every day, sometimes for the same patient. Just the other day I was looking at an EEG and said, "Oh my goodness, this guy's having subclinical seizures." And of course, that's why we ordered it. He was comatose. Then I looked at the filter settings and someone had changed them. They weren't seizures at all, just muscle activity that was read as seizures because of the filter settings.