SUDEP: Sudden Unexpected Death in Epilepsy Explained

SUDEP: the risk most Australians with epilepsy are never told about

There is a conversation that should happen after an epilepsy diagnosis and usually does not.

SUDEP stands for Sudden Unexpected Death in Epilepsy: the sudden, premature death of a person with epilepsy where no other cause is found. It affects roughly 1 in 1,000 adults with epilepsy each year. Most deaths are unwitnessed, and many happen overnight during sleep.

Epilepsy Action Australia describes it as “a little-known phenomenon,” which is accurate and is itself the problem. Families who lose somebody to SUDEP say two things with remarkable consistency: that nobody had ever mentioned it, and that they would have done things differently if anybody had.

That is the case for writing this guide. Not to frighten anybody — the overwhelming majority of people with epilepsy will not die of it, and several of the risk factors are things you can actually do something about. But a risk you have not been told about is a risk you cannot act on, and the things that reduce SUDEP risk are mostly ordinary: take the medication, get the seizures under better control, think about where you sleep and who is nearby, ask about the options you have not been offered.

This guide covers what SUDEP is and what is known about why it happens, the risk factors as they are currently understood, what reduces risk, the monitoring question, how to have the conversation with a clinician who has not raised it, and where to get support if you have lost somebody.

A note before starting. This is a difficult subject, and if you are reading it having lost someone, the support services are listed at the end. The Epilepsy Foundation is on 1300 761 487 and Epilepsy Action Australia’s nurse-staffed line is on 1300 37 45 37. Both provide bereavement support.

What SUDEP is, and what is not known

The definition. A death in a person with epilepsy that is sudden, unexpected, not caused by trauma or drowning, not the direct result of a prolonged seizure, and where a post-mortem finds no other cause.

What that definition excludes, and this matters for understanding the numbers: deaths from status epilepticus, deaths from drowning during a seizure, deaths from injuries sustained in a seizure, and deaths from unrelated causes. Those are all epilepsy-related deaths and they are not SUDEP. SUDEP is specifically the category where somebody dies and nothing explains it.

The mechanism is not established. Research is looking at three overlapping areas: what a seizure does to breathing — central apnoea, obstructed airway, suppressed respiratory drive after a seizure; what it does to the heart — arrhythmias and conduction changes triggered by the seizure; and what it does to arousal — the failure to wake up and reposition or resume breathing. The current working picture is that SUDEP is most likely a cascade involving all three, usually following a generalised tonic-clonic seizure in sleep, in somebody lying prone and alone.

Why that matters practically. If the mechanism involves breathing and failure to arouse, then being in a position where somebody can reposition you, or where an alarm brings somebody to you, is plausibly protective. That is not proven, and it is the reasoning behind most of the advice below.

The numbers:

And the variability. Risk differs enormously between individuals and changes over time in the same person. Somebody with well-controlled focal seizures on a stable medication carries a very different risk from somebody having frequent night-time tonic-clonic seizures and living alone. Which is the whole point of knowing the risk factors.

The risk factors

From Epilepsy Action Australia’s summary of the evidence. Several of these are modifiable, which is the reason to read the list rather than avoid it.

Tonic-clonic seizures — the strongest factor. Particularly during sleep or at night, with risk rising as frequency increases. This is the single most important element, and it is also the one most amenable to change through better seizure control.

Living or sleeping alone. Being unwitnessed and unattended is associated with higher risk.

Medication changes, or missed doses. This is the most actionable item on the entire list and it is covered in detail below.

Frequent seizures — though SUDEP has also occurred in people having very few.

Seizures beginning at a young age, or epilepsy lasting more than 15 years.

Being male and aged 20 to 40.

Excessive alcohol use or substance misuse.

Depression or psychiatric illness. Which connects directly to the adherence question and to the finding that around 20 per cent of respondents to an Epilepsy Action Australia survey reported depression, roughly double the general population rate.

Intellectual disability.

What is not established as increasing risk: absence and myoclonic seizures. The qualification Epilepsy Action Australia adds is important though — missing medication for those seizure types may lead to tonic-clonic seizures, which do carry risk.

Reading the list honestly. Several factors are not modifiable: your sex, your age, how long you have had epilepsy, when it started, whether you have an intellectual disability. Those are worth knowing because they tell you where you sit, not because you can change them. The modifiable ones — seizure control, medication adherence, alcohol, sleeping arrangements, treating the depression — are where the attention belongs.

What reduces risk

Getting the best possible seizure control. Epilepsy Action Australia is direct that this is the best way to lower risk. Everything else on this list is secondary to it.

Which means: if seizures are not controlled, that is not a settled state of affairs to be accepted. Around a third of people with epilepsy do not respond adequately to medication, and for them the options include further medication trials, assessment at a comprehensive epilepsy centre, surgery, neurostimulation and dietary therapy — and Australian referral to those options is frequently years later than it should be. See drug-resistant epilepsy. If you are having regular tonic-clonic seizures and have not been assessed at a specialist epilepsy centre, that is the most consequential phone call available to you.

Taking medication as prescribed. Dull, and the most effective single thing most people can do. Missed doses are a recognised SUDEP risk factor and they are also the commonest cause of breakthrough seizures. What actually helps: a dosette box or blister pack from the pharmacy, phone alarms, pairing doses with a fixed daily event, a repeat prescription set up before you run out, and telling somebody if you are struggling with it. Adherence is not a character test — it is a system problem with system solutions.

Not changing medication without supervision. Including stopping because you feel well, switching brands without advice, or letting a prescription lapse. Medication changes are on the risk factor list for a reason.

Avoiding binge drinking. Alcohol lowers the seizure threshold, interacts with medication, disrupts sleep and is associated with missed doses, which stacks four risk factors at once.

Treating the depression. It is on the risk list, it is extremely common in epilepsy, it is treatable, and it drives non-adherence. See mental health and memory in epilepsy.

Protecting sleep. Sleep deprivation is one of the most reliable seizure triggers, and night-time seizures are the highest-risk category.

Asking for a SUDEP and seizure safety checklist. Epilepsy Action Australia specifically recommends asking a GP or epilepsy nurse for one. These are structured tools that go through individual risk factors and identify which are modifiable. Almost nobody is offered one, and asking by name usually produces it.

And considering the sleeping arrangements. Not sleeping alone, where that is possible and wanted. A monitor or alarm, discussed below. For somebody in supported accommodation, an overnight arrangement built on what the seizure diary shows rather than on an assumption.

Monitors and alarms: an honest assessment

This comes up constantly and the honest answer is more qualified than most marketing suggests.

What the devices do. Bed sensors detecting the movement of a convulsive seizure; wearables detecting movement, heart rate or changes in breathing; audio and video monitors; and in some cases oxygen saturation monitoring. They alert somebody in another room.

What Epilepsy Action Australia says about them, and it is worth quoting the position plainly: they can detect convulsive seizures or changes in breathing or heart rate, they do not guarantee safety, and they may give peace of mind.

What follows from that:

They detect convulsive seizures reasonably and other seizure types poorly. A device built around movement will not reliably detect a focal seizure, an absence, or a tonic seizure without a convulsive phase.

They produce false alarms, which matters because alarm fatigue in a household or a supported accommodation setting is real and leads to alarms being muted.

They only help if somebody responds. A monitor in a house where the only other person sleeps through it, or in a supported setting where the worker is two floors away, is not an intervention. The device is half of a system and the response is the other half.

They are not a substitute for better seizure control. If a monitor is being considered because seizures are frequent and uncontrolled, the monitor is the second conversation and a specialist epilepsy centre referral is the first.

And they are fundable. For an NDIS participant, seizure detection and alarm devices are assistive technology, and the request should include the assessment, the training, the maintenance and — importantly — the response arrangement, not just the device. See epilepsy and the NDIS.

The reasonable position, then: a monitor is worth having for somebody with night-time convulsive seizures who sleeps alone or in a separate room, as one layer among several, with realistic expectations about what it will and will not catch, and with a documented plan for who responds and how fast.

Having the conversation with a clinician

Many Australians with epilepsy will never have SUDEP raised with them. If you want it raised, you will probably have to raise it.

Why clinicians hesitate, which is worth understanding rather than resenting. Some judge that the information will cause anxiety without changing behaviour. Some have limited appointment time and prioritise seizure control. Some are uncertain how to quantify individual risk, which is genuinely difficult. And some simply have not thought about it.

None of those are good reasons not to tell somebody, and the Australian advocacy position — including a documentary Epilepsy Action Australia references as intended to encourage GPs, neurologists and epileptologists to discuss SUDEP and individual risk with patients — is that the conversation should be routine.

What to ask, in these words:

“Can we talk about SUDEP and what my individual risk looks like?” Direct, and it signals that you already know what it is.

“Can I have a SUDEP and seizure safety checklist?” Ask by name.

“Which of my risk factors are modifiable?”

“My seizures are not controlled. What have we not tried, and should I be assessed at a comprehensive epilepsy centre?” The single most important question in this guide.

“Do I have seizures during sleep that I might not know about?” Many people do not know. A bed partner, a monitor, or a sleep study can answer it, and nocturnal tonic-clonic seizures are the highest-risk category.

“Is my medication regimen the best available, and are there interactions or adherence problems we should sort out?”

“Should the people I live with know what to do, and can they be trained?”

And for parents and support providers: ask for SUDEP to be addressed explicitly in the seizure management plan, including the overnight arrangement and the rationale for it. The delivery side of seizure support is covered in epilepsy and seizure support.

For families and support workers

Know the overnight arrangement and why it is what it is. If somebody has night-time convulsive seizures and sleeps unobserved with no monitor and no response plan, that is a gap worth raising in writing.

Position matters. Current thinking implicates prone position and failure to arouse, which is why repositioning somebody onto their side after a seizure and staying with them during the recovery period is part of first aid rather than an optional extra.

Stay through the recovery, not just the seizure. The post-seizure period is when breathing is suppressed and arousal is impaired, and it is when leaving somebody alone matters most.

Report every seizure, every time, in the diary. Including the ones that seem minor, including the ones at night that were only noticed from a wet bed or a bitten tongue in the morning. The diary is what drives the treatment decisions that reduce risk.

Report any missed or refused medication. Not as a compliance issue — as a safety one.

And escalate uncontrolled seizures rather than normalising them. A support provider that records twelve tonic-clonic seizures a month for two years without anybody asking whether this person has been assessed at a specialist centre has failed at something important.

If you have lost someone

Support exists, and it is specific to this.

Epilepsy Foundation — 1300 761 487.

Epilepsy Action Australia — nurse-staffed helpline on 1300 37 45 37, with bereavement support for families and a Facebook group for people who have lost somebody to epilepsy.

Your state epilepsy organisation, which can connect you with other families.

The Epilepsy Deaths Register, an international register that families can contribute information to, which is how the evidence base on SUDEP improves.

And one thing worth saying directly, because families say they needed to hear it: SUDEP is not a failure of care. It happens in people whose epilepsy was well managed, in people who took every dose, in people who were doing everything right. The risk factors describe populations, not verdicts on individuals. If you are going back through what you could have done differently, the honest answer in most cases is nothing.