Epigraph Vol. 24 Issue 2, Spring 2022

"Why are there so many people?" - Seizures in the Canadian Arctic

Reported and produced by Nancy Volkers, ILAE communications officer

Could the annual dramatic shifts in the Arctic’s day/night patterns have an effect on seizures? One researcher went looking for answers – and found more than he bargained for. His research reveals a public health crisis in one of the wealthiest countries in the world, highlighting the needs of geographically isolated communities and Indigenous peoples. (He also found intriguing results to his original question.)

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Podcast Transcript

This is one episode, but it’s really two stories. We begin with a researcher interested in the relationship between sleep patterns and seizures in the Arctic.

He conducts a study to look for answers, focusing on an isolated region of northern Canada. He’s looking at cases of status epilepticus – an emergency condition in which someone is having persistent seizures for many minutes, hours, and sometimes days. He wants to know: Do the extreme changes in daylight length have an impact on seizure severity?

The data are not what he expects.

Dr. Marcus Ng: Why are there so many people? We have way more people than we expected. We kind of stumbled into this public health crisis without knowing it. We have a lot of data points, but each of those data points is a person who needs medical treatment and has to be flown thousands of kilometers away. We were looking for a scientific, circadian, day-night seizure question, and then it became a question of why are there so many people seizing up there?

That’s Dr. Marcus Ng. He’s associate professor of neurology and director of the Dreamspike Research Laboratory at the University of Manitoba. We talked with him about his 2021 publication on status epilepticus in the Kivalliq Region of Nunavut, Canada. There, anyone in status epilepticus is flown by helicopter to a single hospital in Winnipeg, Manitoba. His research focused on 11 years of data on these emergency evacuations.

Here’s Dr. Ng.

Dr. Marcus Ng (Canada)
Dr. Marcus Ng (Canada)

Dr. Ng: The point of this whole project initially was to look at the distribution of seizures in sleep. Sleep and epilepsy is my particular research interest. My mentor at the Brigham in Boston is a circadian rhythm expert, and we thought what better environment to look at this than in the Arctic, or in theory the Antarctic, where winter and summer are extremes – summer is 24-hour daylight, winter is 24-hour night, and seeing how seizures are impacted by this – do they get worse if it’s all sun all the time, or all dark all the time, and seeing if that has an impact on status epilepticus, seizure severity, so that’s how this project came about. We got approval just to look at what we thought was going to be a very small data set.

The data set was not small. They saw about 10 cases of status epilepticus each year, in a population of just over 10,000 people. That translates to the highest annual incidence of any published study, anywhere in the world – and it was significantly higher than overall Canadian estimates.

Dr. Ng: Statistics Canada published a nationwide prevalence survey in 2016 that was based on a community survey in 2011 that had a lot of caveats and disclaimers about how they got their data. It excluded the Arctic territories and persons in the armed forces. It was better than nothing. That national prevalence data showed a number in line with industrialized countries. Looking at a pure data set here, where we are by virtue of health care infrastructure situated at a bottleneck where all the patients are flown here, we were able to look at a single site and come up with, I would say, a more representative number and that number is a lot higher than the nationally quoted average. And in fact, it’s in line with low- to middle-income countries around the world.

The article does look at other published literature on status epilepticus, but keep in mind that those studies are mostly biased toward high-income countries. So relative to those countries, Nunavut would have the highest published rate of status epilepticus to date. I’m not saying that should be the take-home message, because I’m sure it’s just a matter of time before someone else finds a higher rate somewhere else. But as of this moment, in the published literature with all the biases that holds, the highest rate of status epilepticus would be in Nunavut, Canada.

Most studies of status epilepticus find that about 40% of people have a history of epilepsy. This study found only 16% had a history. What are some of the hypotheses or speculation you could provide about why that number is so low?

Dr. Ng: Yeah, I like that word speculation because that’s really all we have at this point. I guess I would caution that while relatively the numbers are very high, absolutely we’re dealing with a small population. We have about 10,000 people in total in the Nunavut region. Geographically, Nunavut has three regions, and the region that’s services by the health care center I’m at, the Kivalliq region, has about 10,000 people. Within that, there are a disproportionately high number of people flown out for status, and then, like you say, only 16% had a history of epilepsy once they came down to Winnipeg and we looked at their charts, whereas the number like you say should be around 40%. It’s eerie how well studies agree on that number, independently, just looking at epilepsy history – some are a bit lower, some higher, but it’s around 40%.

Top five causes of status epilepticus in 99 people evacuated 117 times from the Kivalliq region of Nunavut territory, Canada.
Data from Ng & Pavlova 2021

Top causes per capita (2009-2020)

Idiopathic 22.2%
Self-harm/substances 21.1%
Hemorrhagic stroke 20.2%
Systemic illness 19.2%
Epilepsy 16.2%

In the study there’s some speculation about what would have happened if we assumed the people being flown down had the 40% and redid the math – it would end up being that everyone in Kivalliq has epilepsy, which is unlikely, or we’re missing a lot of people who would have been diagnosed, had they received care sooner or there was greater awareness of epilepsy.

We do speculate about how there’s limited knowledge of when seizures become epilepsy and it seems like, just because seizures are so endemic to that area, there might be familiarity on the ground with seizures. But when it’s epilepsy, so when to take action to prevent seizures as opposed to reacting to a seizure, or even normalizing the occurrence of seizures, all remains to be explored.

About 90% of people in the Kivalliq region are Indigenous, most of them Inuit. If there’s an epilepsy diagnosis gap, it could be partly due to historical mistrust of Western medicine.

Dr. Ng: That is a huge other issue that adds to the dynamic between Western medicine, and awareness of epilepsy, and prevention of injury that can come from seizures.

And, as with many other cultures around the world, people in the Kivalliq region may hold beliefs that seizures stem from a supernatural cause, rather than a medical one. But Dr. Ng says it’s oversimplifying to assume the entire region views seizures the same way.

Dr. Ng: My personal interactions have come mostly through patients who are flown down on an elective basis so they’re still conscious and not sedated due to status epilepticus. I’ve heard personal stories about a supernatural framework, where there’s almost a shamanistic approach to understanding these phenomena. I can’t say much about the specifics of how individual seizures are interpreted in the Kivalliq region, and I almost feel like it’s a bit of a fallacy to lump the region together. There are settlements that are geographically isolated from each other, hundreds of kilometers apart with no roads. So I don’t know if we’re even dealing with microcultures within each settlement and the beliefs in each settlement dictate whether or when someone seeks care for seizures.

You heard him, right? Isolated communities, hundreds of kilometers apart, no roads. How does someone in status epilepticus get care?

Dr. Ng: If someone has a seizure in one of the communities in the Kivalliq region and they choose to seek care or someone brings them to care because it’s recognized as an emergency, which status epilepticus would be, given that the seizure doesn’t stop. That person is incapacitated so I hope they would present to medical attention in time.

There usually is a nursing station in each community. I’m not aware of a formal hospital facility. The nursing station might act as a clinic, and then the nursing station would be staffed by a locum – usually there’s not a permanent practitioner there, although I could be mistaken as there are seven communities so they could have seven different systems. But usually it’s been a locum, who comes by every few months and there’s really not much continuity of care.

For most of the communities in Kivalliq, the nursing station is the center of medical care. The largest community does have a health center, not a hospital, staffed by two or three physicians, and the second largest community has one full-time physician. The others do not – they use these traveling physicians, locum tenens, who appear for about a week at a time, every couple of months.

Dr. Ng: And then that locum tenens would have to seek additional medical advice or support to fly out the patients, and that’s when the interaction with non-Nunavut systems occurs, which opens up the discussion to federal vs provincial jurisdiction of health care. I think health care is a provincial jurisdiction so here in Manitoba things are run in a completely different way than in Ontario or Quebec. But the territories are not provinces, so in some way which I’m not an expert on, health care is delivered through a federal mechanism, and there could be additional Indigenous mechanisms on top of or in parallel to the federal system.

And then it becomes a matter of catchment areas. Kivalliq is covered by Winnipeg, so people are flown to Winnipeg if there’s a need determined on medical grounds. They have limited facilities there to start treatment and make sure it’s effective. When they come here, by the time they’re in super refractory status or refractory status, they’re in the intensive care unit. So we’re dealing with a last-minute intervention to prevent terminal injury or death in an emergency situation, and not so much taking up preventive aspects – outreach or looking at people who’ve had a seizure or a few seizures and seeing how we can prevent status – it’s more the other end, someone is in status and they have to be flown out and they come here.

So what does the treatment course look like for someone who presents with status epilepticus at a nursing station? How much can be done there and how much has to wait until Winnipeg?

Dr. Ng: I think most people are treated in the nursing station or the Medevac or both, but it’s empiric treatment and there’s a high level of discomfort. For example they might be given a benzodiazepine, and the nursing station might not have phenytoin to load with, so they have to be flown out to get phenytoin. Or if they have phenytoin and the patient is not waking up, maybe they’re in non-convulsive status, and how can they verify the patient has stop seizing – that requires EEG so they have to be flown out. So empiric treatment may be started before or during the fly-out process, it has to be verified in a different setting, which is Winnipeg.

The title of your paper mentions a “public health imperative hidden in plain sight.” When we think about areas of the world that require attention to improve epilepsy care, we usually think about low-resource countries. Yet here’s Kivalliq, part of one of the wealthiest nations in the world, with the highest documented rate of status epilepticus and some clear barriers to timely diagnosis and treatment. How can we talk about this in a useful way?

Dr. Ng: Those are great points and important questions. Probably the first step is breaking down the heuristic that countries are single monolithic blocks. With so much diversity in the world, it’s convenient to think of countries as a cohesive unit, but there’s so much diversity within them, and it’s probably worth looking at specific regions. Not simply to get a more accurate snapshot of that country as a unit, but also to look at how different units are addressing issues within themselves and applying those lessons to other places in the world and seeing if they work or can be improved upon.

A second point is to look at persons without countries, per se. What I’m getting at is Indigenous populations. Indigenous populations who don’t automatically become attributed to a political unit. They might straddle borders and have ancestral homelands in different places. Persons who are not strictly associated with a particular country, there should be focus on those people too – and also refugees, people escaping persecution. These are marginalized populations that should be looked at. Those are the two main points that come to mind right now.

Map of the Nunavut regions in Canada. Author: Maximilian Dörrbecker (Chumwa). Creative Commons Attribution-Share Alike 2.5 Generic license.
Map of the Nunavut regions in Canada.
Author: Maximilian Dörrbecker, used with permission under the Creative Commons Attribution-Share Alike 2.5 Generic license without changes.

Let’s go back to the journey of someone with status epilepticus in Kivalliq. They arrive at a nursing station, they are helicoptered to Winnipeg, and then what happens next?

Dr. Ng: They have to deal with health care challenges at home and then once they’re flown to Winnipeg, they face challenges in Manitoba. That is a double whammy that’s additionally unfair to them. By analogy, people living in the Arctic territory of the Yukon would be flown to British Columbia, and people in the Northwest Territory would be flown to Alberta. Given that Alberta and British Columbia have more resources than Manitoba, there’d be less of a double whammy, if a double whammy at all.

For status epilepticus, in an emergency situation, we have an ICU and we have EEG in Winnipeg so I think that is all right, though that was before COVID of course – with COVID, all bets are off. But even before COVID, it’s where the prevention comes in. The prevention of recognizing epilepsy, looking at anti-seizure medications, the role of epilepsy surgery, preventing status in that large subset of people who have epilepsy, that aspect I think was trying. At the moment, there is no epilepsy monitoring unit in Manitoba for adults.

If you’re a patient in Nunavut and you have a number of seizures, they’re impacting your life and you want to do something about them, so you go to the nursing station. You get continuity of care and a referral to Winnipeg. You’re able to see a neurologist in Winnipeg and you’re admitted therethere were 2 beds there for 1.5 million people – even going through that entire process, if you are deemed to be a surgical candidate, then you’re hit with the need for an additional referral for somewhere else in the country to have the process mostly repeated to see if surgery can be offered to you.

This is one episode, two stories. Let’s go back to the first story and the original question – do dramatic changes in daylight affect seizure frequency or seizure severity?

In February 2022, Dr. Ng and colleagues published research analyzing the 11 years of data on status epilepticus in Kivalliq. If there were no annual pattern, they should have seen about 8% or 9% of all evacuations occurring in each of the 12 months. But they found that 19% of the evacuations took place in May – the first full month of the year with 24-hour daylight. Some other analyses showed clustering of evacuations in April, in which darkness is gradually replaced by dusk. The researchers suggest the increase in seizures may be due to people getting less sleep due to more daylight.

Dr. Ng: Going back to the original question, I am really curious about how extreme variations in day and night and light and dark affect seizure frequency. And then the interaction between possible genetic polymorphisms in populations who have historically lived in these conditions and see if they differ from people who aren’t subject to these conditions. I hope to look at the epidemiology of status epilepticus at the equator versus the poles and see if they differ – is there a latitudinal effect on seizures and epilepsy? Are there genetic polymorphisms that account for different susceptibilities to seizures? A study there could be looking at recent newcomers to the Arctic versus those with ancestral homelands in the Arctic, and do seizures differ in that regard.

An interesting parallel in the study was looking at Finland – Finland is at the same latitude, Kuopio, and they have a high rate of status epilepticus as well in their publication recently. Latitudinally they’re in the same region, but socioeconomically and genetically it’s a very different population. So I think there’s a number of collaborations that could be forged, not just politically or from an advocacy standpoint but also scientifically, based on these studies.

The Finland study was published in 2019 in the journal Epilepsy & Behavior – you can find links to all the studies we talked about in the show notes to this episode.

 

Studies mentioned or used as sources of information:

Status epilepticus in the Canadian Arctic: A public health imperative hidden in plain sight. Epilepsia Open 2021

Circannual incidence of seizure evacuations from the Canadian Arctic. Epilepsy & Behavior 2022

Incidence of the different stages of status epilepticus in Eastern Finland: A population-based study. Epilepsy & Behavior 2019

Addressing provider turnover to improve health outcomes in Nunavut. Canadian Medical Association Journal 2019