When Jo Puckett woke feeling disorientated and confused one morning, it was her fiancé who explained what had happened. She had suffered a seizure in her sleep.
“I had no memory of it at all,” says Jo, 34. “I just felt completely exhausted.”
The seizure appeared to come without warning. Jo was fit and healthy at the time, living in Berkshire with her fiancé, Stephen Sorenson, 35, an account executive.
Once Jo was fully awake, Stephen took her to A&E. Doctors carried out blood tests, a brain scan and an electrocardiogram (ECG) to examine her heart, but every result was normal.
Two weeks later, however, Jo had another seizure. Within a few months, the episodes were happening every day, preventing her from driving and forcing her to give up her job as a mental health rehabilitation consultant.
Epilepsy initially appeared to be the most likely explanation. The condition runs in Jo’s family, and her symptoms seemed to match those she associated with the disorder.
Further hospital investigations ruled epilepsy out. Instead, Jo was diagnosed with functional neurological disorder (FND), a condition affecting the nervous system that is frequently mistaken for epilepsy.
Like many people — and even some doctors — Jo had never heard of FND. Yet it is thought to affect between 50,000 and 100,000 people in the UK. The condition can begin at any age, although it is significantly more common in women.
Jo Puckett, 34, woke one morning feeling disorientated and confused. Her fiancé told her she had suffered a seizure in her sleep — an episode later diagnosed as FND
FND occurs when the brain and nervous system fail to send or process signals correctly. However, there may be no visible structural damage, explains Dr Steve Allder, a consultant neurologist at Re:Cognition Health in London.
“Someone with FND may experience seizures, weakness, tremors, abnormal movements, numbness or difficulty walking,” he says.
A range of factors, including illness, injury, pain, stress and psychological difficulties, can trigger FND, according to Dr Allder. However, he says there is not always an identifiable cause: “In some cases, there is no obvious trigger at all.”
Dr Faye Begeti, a neurologist and neuroscientist at Oxford University Hospitals, says FND is often explained as a “software” problem rather than a “hardware” problem.
“The hardware — the brain, spinal cord and nerves — is intact, which is why investigations are usually normal. But there seems to be a glitch in the software, affecting how the brain processes information,” she says.
“This also explains why symptoms can be so variable and unpredictable: the ‘software glitches’ may differ from one person to another,” she adds.
Symptoms may become more severe with tiredness, pain, stress or poor sleep.
Because FND can produce symptoms associated with several neurological conditions, it is often mistaken for epilepsy, multiple sclerosis, Parkinson’s disease or a stroke, says Dr Allder.
FND-related seizures, like those experienced by Jo, are especially easy to confuse with epileptic seizures because the two can look remarkably alike.
There are, however, some differences. Dr Allder says an FND seizure often lasts longer and may involve tightly shut eyes, while a person having an epileptic seizure will often have their eyes open.
Epilepsy is a separate condition, caused by a sudden burst of abnormal electrical activity in the brain.
In the past FND was only diagnosed after other conditions – such as epilepsy and Parkinson’s, for instance – had been ruled out.
But there are symptoms that can help identify FND, such as a tremor that changes or disappears when the person is distracted, or having a seizure but brain scans shows no signs of the abnormal electrical activity that would be seen among those in epilepsy, says Dr Allder.
Jo’s hospital tests all came back normal after both her first and her second seizure – which took place two weeks after the first, while she was a passenger in her sister’s car.
‘I was in the back and felt a little claustrophobic,’ she says.
‘The next thing I remember is coming round with my mum supporting my head so it wouldn’t hit the window.’
Jo was horrified when her family explained she’d had another seizure.
‘I began crying hysterically. Hearing it had happened again made it all very real and scary, It felt like I was at risk of it happening anywhere at any time,’ she says.
Jo was referred to a neurology specialist – by the time of her first appointment in September 2023, she was having around two seizures a week and shared multiple videos of her seizures taken by her family. She had an MRI scan and EEG to record the electrical activity in her brain.
The footage of the seizures together with the scans showing no sign of abnormal electrical activity in the brain confirmed Jo had FND.
Within a few months, the seizures became a daily occurrence – sometimes occurring twice a day – forcing her to give up work and driving.
They also led to her developing a significant pain in her back and weakness down her left side.
‘Walking, holding objects and everyday tasks became difficult,’ says Jo.
‘I found myself having to consciously tell my left leg to move. It felt as though my brain and body were no longer communicating properly so I was referred to physiotherapy and later, a neurophysiotherapist [who helps improve the function of patients with neurological conditions].’
Dr Steve Allder, a consultant neurologist at Re:Cognition Health in London, says that in some cases there is no obvious trigger for FND
Unlike epilepsy, there are no medications specifically used to prevent or treat FND seizures.
Treatment focuses on rehabilitation, including physiotherapy and psychological therapies, and teaching people to find ways to manage their condition.
Stress, anxiety or previous trauma can play a role in triggering seizures for some people, says Dr Allder.
There was no clearly identifiable trigger for Jo’s seizures – so her treatment focused on helping her to understand her condition and developing coping strategies, such as breathing techniques.
Autism and ADHD may also play a role – and Jo was surprised when one FND specialist she consulted asked if she’d ever been assessed for either condition.
‘He explained that people who are neurodivergent appear to be more likely to develop FND,’ she says.
Following assessments, Jo was diagnosed with both ADHD and autism in September 2024.
The possible link between FND and neurodivergence is an area of growing research, says Dr Begeti.
‘Evidence is still accumulating – but we know autism appears more commonly in people with FND than you would expect by chance,’ she says.
Dr Begeti cites a major review of previous research, published in 2025 involving 11,000 participants, which estimated that around 10 per cent of people with FND have autism, compared with roughly 1 to 2 per cent of the general population.
‘There is evidence for ADHD too, with studies suggesting rates are several times higher in people with FND than in the general population,’ she says.
Jo’s life now looks very different from how it was three years ago.
She has around five seizures a week which can occur out of the blue when she’s asleep, watching TV or even in the shower.
‘I also have involuntary movements, tics, migraines, pain, brain fog and overwhelming fatigue,’ she says.
‘I don’t feel safe being alone, and leaving the house can feel like a military operation – Stephen and I have to prepare for every possible scenario in case I have a seizure.’
She adds: ‘Some mornings my legs simply won’t move – I often describe it to my family as “disability roulette”, because I genuinely never know how I’m going to wake up.
‘I’ve banged my head in the shower and been concussed, and I’m always covered in bumps and bruises.’
Afterwards she feels confused, exhausted and unable to function properly.
And she never knows when the next seizure will happen.
‘Sometimes it feels like I’m improving and have a couple of days seizure-free,’ she says.
Relaxation techniques have helped her to be more patient with her condition, ‘but I still find it hard to accept that this is something I’ll be living with for the rest of my life’, she says.
Stephen proposed in 2024 – a year after her FND symptoms started – but the wedding is currently on hold while she learns to deal with her condition.
In the meantime, Jo is keen to spread awareness of FND and seizures.
On one occasion she had a seizure in the middle of the supermarket while out with her mother: ‘Apparently another shopper simply stepped over me to reach a packet of crisps on the shelf,’ Jo recalls.
She has also encountered a lack of understanding about her involuntary twitching, which she describes as ‘like someone has tied string to my head and is pulling back hard.’
Even healthcare professionals have been known to make hurtful comments such as ‘just stop twitching’, she says.
Dr Begeti often hears of patients being told their FND symptoms are ‘all in their head’ – something she finds annoying as these are ‘real, involuntary and often frightening.’
Yet some people with FND do improve, including those severely affected or using a wheelchair, she says.
Jo recently regained some independence after investing in an electric wheelchair and hopes to be matched with a medical alert dog to help detect an impending seizure.
She recently wrote a children’s book about FND, called Scrambled Signals (available on Amazon) to help explain the condition to young children.
‘I hope my story helps more people recognise FND, understand what people living with it go through, and realise that no one should have to face it feeling alone.’
