A novel patient-reported outcome measure for epilepsy: The impacts of seizures and treatment

Is there a fast, simple way to measure whether someone with epilepsy is doing "better" or "worse" compared with a past clinic visit? Not really. Seizure count is often considered a standard, but multiple small seizures may have less impact on someone's life than a single generalized tonic-clonic seizure. In this episode, we talk with authors of a study on an outcome measure that factors the impact of seizures as well as the impact of treatments.

The study: Validation of the seizure-related impact assessment scale 

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Transcript

Nancy Volkers: In this episode, we're discussing a study from the journal Neurology published in August 2025, titled “Validation of the Seizure-Related Impact Assessment Scale.” I'm here with senior author Dr. Jacqueline French, and first author Dr. Emma Foster, and I'd love for both of you to introduce yourselves.

Dr. Jacqueline French: Hi, I am Jacqueline French. I'm a professor of neurology at NYU Langone in New York. And in addition, I am the president of an organization called the Epilepsy Study Consortium, which is a nonprofit that tries to improve the conduct of clinical trials.

And in addition, I'm the medical director of the Epilepsy Foundation, working with people with epilepsy to improve their lives.

Dr. Emma Foster: And hi, I am Emma Foster. I'm an adult neurologist from Melbourne, Australia, and an early career researcher at Monash University.

Nancy Volkers: Thank you both. It's great to have you here. And I wanted to start with some context around the study and seizure impact [00:01:00] scales in general. What are these scales for and why did you develop this particular one, which I guess we can refer to by its acronym, SERIAS.

Dr. Jacqueline French: So there were a couple of reasons. Actually the concept of the SERIAS scale was devised about 20 years ago, believe it or not. And the reason is that there is a quote from James Cameron that says that everything that counts can't be counted, and everything that can be counted doesn't necessarily count.

And we have a tradition in epilepsy, as in many diseases, to say, "We're going to count the number of seizures that you have, and then we're going to say how much seizures impact you." And of course, that is not correct, because a seizure can be a very small, even one without altered awareness where you have perhaps a [00:02:00] funny smell or you see sparkling lights and for a second that may occur. Or you could have one seizure that is a tonic-clonic seizure, and after that you have memory impairment for three days that impacts your life. How do you capture the impact of the seizures, rather than just counting them? 

In addition to that, I was concerned about the trade-offs that people are making when they are taking medication or treatment for their seizures. If an individual has to take a very high amount of medication in order to control seizures, but the medication in and of itself is now impacting their ability to function, we don't capture those tradeoffs. So that was sort of what was whirling through my head. 

And I came across a scale that I really loved in the migraine space called MIDAS, which is the Migraine Disability Assessment [00:03:00] Scale.

And it was quite simple. It said, how many days or portions of days do migraines impact your life? It did not talk about the treatment for migraine, so that was a part that I included, in terms of how many days or portions of days do the medications impact your life.

Nancy Volkers: Perfect. Thank you. So could you describe the scale itself? Like how many questions are there, what is asked, how is it scored? Things like that. 

Dr. Emma Foster: Absolutely. So as Dr. French said, it's really getting that balance between the quantitative and the qualitative impact of seizures and also the impact of antiseizure medication or other treatments for epilepsy, and putting them in the same common denominator, which is how many days do you lose within a month because of one of these things?

So our scale has five questions and then a visual analog scale. The visual analog [00:04:00] scale is pretty easy to understand. It's a number between zero and 100 saying at the moment, how impacted are you? With zero being no impact at all, and 100 is a very intense impact. So people find their way on the scale. 

The five questions themselves, the first question is about how many days in the last month has most of the day been taken over by seizures or seizure-related problems? 

So we recognize that even in a brief focal impaired awareness seizure, if it may be associated with urinary incontinence, for example. The seizure itself might be short, but the consequences of that seizure means the person has to stop their work, go home and change. So that's been a big impact to their day. 

The second question is how many days in the last month have you been mostly impacted because of treatment side effects? There are a lot of side effects associated with antiseizure medication. A common one is tiredness or cognitive [00:05:00] fogging. And so people might say that's pretty pervasive most of the days, last month I really had some struggles thinking. 

The third question is looking at productivity partly reduced because of seizures or seizure-related effects. So how does your activities at work, home school get impaired? 

Question four is about the social impact of seizures or seizure-related activity. How many days in the last month did you miss family, social, or non-work activity? 

Number five is, for the treatment side effect side of things, how many days in the last month did you miss because of treatment-related side effects? 

Dr. Jacqueline French: And people can, you know look at the part of the SERIAS scale that they're interested in.

So if they're interested in whether seizures are getting better or worse, or the impact of seizures is getting better or worse, then they can look at the seizure-related questions and if they're, they're interested in, well, what did my medication do? And is somebody better or [00:06:00] worse in that regard? 

You know, you can imagine the two sides doing this, going, I'm sorry, I'm using my hands. You know, one going up and the other going down. Or the ideal of course would be that both of them go down and less days are impacted, but we want to make sure that if the seizure impact goes down, we're not increasing the impact of medication to the point where we actually haven't provided any more useful days to the person.

And there are not very many scales that measure both in the same instrument, in five questions that can easily be answered. 

I talked about the MIDAS scale. The MIDAS scale is actually now in clinical use, but it has been in the public domain for decades now. So there has been an opportunity to do a lot of work with it. But now the migraine community actually uses that scale and it is [00:07:00] considered acceptable to use it to determine whether somebody, for example, should be provided with the more expensive medications or whether you can just use the starting medications. We now have some quite expensive medications in the migraine space.

This comes up very frequently in epilepsy of course, where we also are having more expensive medications. How should we prioritize those and who should we, most urgently use them for? 

And anybody with migraine now can go to the internet and take the MIDAS scale. And there have been some public service campaigns where people are told, “Guess what? Your headaches are significant enough that you should be seeking out specialty care. Your level of severity warrants you seeking a higher level of care,” and people have the opportunity to understand that.

So there are many possible uses in the [00:08:00] community. 

We are also excited about the use in clinical research and clinical trials, which is an area near and dear to my heart because in clinical research, back to the “everything that counts can't be counted” – in clinical research, we only measure what we call countable motor seizures. Countable motor seizures are ones where somebody can observe: having motor movements, losing awareness. And in addition to that, they're long enough and discrete enough that they can be counted. 

But there are actually, among all of the ILAE-described seizures, there are more seizures that we consider uncountable in clinical trials than there are ones that we consider countable. 

So particularly in children with developmental and epileptic encephalopathy, [00:09:00] you have absence seizures. They happen, but they're just not separated from each other in a way that you can count. Like you’re telling the parent, if there was a flock of birds flying over their head, you're telling them, “Okay, quick tell me how many birds there were.” You know, it's impossible. So we say they're uncountable. Same thing for my myoclonus. Same thing for tonic and atonic seizures that don't lead to a fall. Infantile spasms, and I can go on and on. 

So if you can't count them in a clinical trial, how do you tell whether somebody's getting better or not?

And again, it's very beginning of this, so we're going to have to see how it works out. But already SERIAS has been implemented as an experimental outcome in a number of trials and we'll see whether it can distinguish and how it differs, if it does, from just a pure count.

Nancy Volkers: So who was involved in the study and how was the [00:10:00] data collected? I'm assuming people with epilepsy were taking this SERIAS assessment at various times. Could you talk a little bit about that?

Dr. Emma Foster: On our team, we had Dr. French as our senior as our senior investigator. And we had Dr. Charles Malpas, who was one of our vice statisticians who has a lot of experience with validating scales. He provided the statistical analysis and expertise in terms of how we are going to set up our study. We also had investigators who were in the epilepsy field themselves who gave feedback and input, so a lot of experienced epileptologists. We also had neuropsychologist Dr. Genevieve Rayner, and very importantly we had a consumer. We had someone who lived with epilepsy who was involved in our study from the start, and gave important input onto how we would phrase the questions on the series, how we formatted it. He ran through and gave it a few trials and gave feedback to improve clarity. And then throughout the [00:11:00] trial, he gave feedback on the data as we got it. And so that was our team. 

The study itself was a prospective longitudinal study. So we were in a center, one of Australia's largest epilepsy centers, where we see a whole range of people who had epilepsy, from new-onset epilepsy through to people who have lived with epilepsy for decades. These are adult patients, so from age 18 and up. In Australia we tend to separate out our hospitals between pediatric hospitals and adult hospitals. SERIAS has been designed at this stage to be self-report, and so generally the self-report tools are for adults who have a reasonable comprehension of English language. So that was one of the inclusion factors as well. 

We really opened it up to a large range of people with epilepsy to really get a thorough understanding of how SERIAS performed. And so we had people on monotherapy, so just a single anti-seizure medication, through to [00:12:00] people who had vagus nerve stimulators implanted, people on ketogenic diets and people who had epilepsy therapy.

We asked people to complete the scales at three time points: baseline, three months, and six months, and that was to get a longitudinal feel if treatment had changed in the timeframe of the study. Or if the seizures had changed, we would be able to see if SERIAS was sensitive enough to pick up those changes as well.

In addition, about half our patients completed SERIAS two weeks prior to entering the baseline data point, and that was to see if there was consistency within that very short timeframe, because if SERIAS responses changed greatly within two weeks, it would be unlikely that there'd been a massive change in treatment or seizures during that time. It just made sure that we had a reliable instrument to start with. 

In total we had 90 people that completed the series at the baseline time point. Most people reported that they had at least one day of disability. And we found that the [00:13:00] greater disability was negatively correlated with quality of life. So that means if you reported high disability, you also self-reported that your quality of life was lower. So that tracks what would be expected. 

We also found that if you reported greater disability, you tended to report greater depression scores and anxiety scores and we had a generic kind of version of the SERIAS, greater life disability scores as well.

So this is a way that we sort of tracked that SERIAS had ecological validity. It was measuring what we anticipated it to measure. So we found that SERIAS was reliable in all the different ways that we measure reliability.

We did have a large variety of adults with epilepsy that did participate in the study and we would say that half our cohort actually were seizure free at the time they did it. So it might be a reasonable representation of the general population with epilepsy, but it's still not a general population cohort.

Dr. Jacqueline French: I just want to add there that [00:14:00] again, this is the beginning and we hope that people will start to use it and add to the database and use it in different ways to understand what its strengths and weaknesses are beyond the work that we did. So for example, we only looked at adults who could answer the questions. We didn't look at parents who were answering on behalf of children. We did talk about the fact that that might be something that we do in the future. We only tested it where people were thinking back over the last month, but we really want to know what happens if people respond like a diary and do it every day.

So, much more research to come.

Dr. Emma Foster: It's such a simple tool on the outside, but when you begin to unpack what it actually covers in terms of quantifying and qualifying and putting two separate impacts onto one page in a common denominator, which is time lost, [00:15:00] it fills a very unique and very important gap in the tools that we have available to us. So I think there's a very big need for SERIAS and tools like that going forward, both for clinical trials and clinical management. 

Nancy Volkers: Is there any concern about conflating the effects of seizures and the effects of treatment? You know, is my exhaustion because I had a seizure, or is it because of the anti-seizure medications that I'm taking?

Dr. Jacqueline French: It is a very good question. And you know, when people answer quality of life instruments or other things, you have to understand they're interpreting it through their own lens. So it's not an absolute truth. But what they are telling you is these are the days that I can't function or I am not as functional, right?

So at the end of the day, there may be a little bit on one [00:16:00] side of the line or a little bit on the other side of the line. It can also happen, by the way, that people misinterpret their comorbidities as having been caused by a treatment when actually you could take all the treatment away and some of those memory problems and other things would still exist. But it is, you know, in some way saying this person is not functioning well. You need to pay attention to that. What we are looking for, of course, is also change. How this instrument is able to demonstrate a change for the better or for the worse.

One thing about the validation that we did is we said this instrument tracks well with all of the other available instruments to tell you that the disability is real, but is it sensitive to change? These are things that we need, again, to do more research to understand.

END