Last year Tracey McMahon woke in the middle of the night with a blinding headache – ‘at first I thought it was a bad migraine’.

But, as she recalls, ‘when I got up to go to the bathroom, everything suddenly went black and I couldn’t see anything. That had never happened before, so I was really worried’.

Tracey, 43, a mental health nurse, who lives with wife Deena, 58, a retired civil servant in Rossendale, Lancashire, adds: ‘Deena saw me standing in the bedroom stock still but I couldn’t move as everything was black.’

From the age of 11, Tracy had suffered from migraines with aura – severe headaches with neurological symptoms such as seeing bright lights and tingling on one side of the body.

But her attacks had been increasingly severe and frequent in the previous year even resulting, on more than one occasion, in a dash to A&E.

‘I’d come in from work and suddenly felt tired and woozy and laid down on the couch,’ she says.

‘Then as I got up it felt like someone had hit me at the back of my head with a baseball bat.

‘I’d also had slight drooping on the left side of my face and a throbbing pain that radiated from my eye through to the back of my head.

‘And I couldn’t bear any exposure to light. I’d actually gone to A&E with a blanket covering my head.’

She was convinced it was a stroke, but after an eight-hour wait in the emergency department, Tracey was told by a doctor she’d just had another bad migraine, as a CT scan didn’t show any signs of a stroke.

However, Tracey believes she may have suffered a mini-stroke, linked to being a migraine sufferer; migraines are known to be a risk factor for stroke in younger people – often as a result of an undiagnosed hole in the heart (which we’re all born with, but which in some people, such as Tracey, never closes up).

Over the following months Tracey (unaware of the hole in her heart) found that her agonising attacks came daily, forcing her to take several weeks off work.

‘My memory was bad and I couldn’t find the right words when I was speaking,’ she says.

‘I also had some left-sided weakness and bad light sensitivity and couldn’t go outside into public spaces as it would trigger an attack – when I went back to work, my office had to be dimly lit.

‘I started having kaleidoscope-like vision disturbance where I’d see a rainbow of pink/yellow and blue/green colours.’

Worried, Tracey paid privately to have an MRI – the gold standard for finding signs of a stroke.

But it, too, found no evidence of a stroke.

Instead, the neurologist diagnosed a thunderclap headache, a severe headache that starts suddenly and causes explosive pain.

He prescribed topiramate, an epilepsy drug that’s used to treat migraines, which reduced the migraine attacks to once a week.

Then last November Tracey suffered another full-on attack, with crushing pain, double-vision and poor balance.

She called an ambulance but when the paramedics heard her medical history ‘they dismissed my symptoms as a migraine attack, told me to take my migraine medication – and then left’.

By the next morning she had pins and needles in her face, arm and left leg, a ‘heaviness’ in her left leg and unsteadiness when she tried to walk.

Once again, Deena rushed her to A&E – but yet again, a CT scan found nothing abnormal.

‘But when the nurse asked to lift my arms above my head, my left arm dropped, and they noticed I had nystagmus (wobbly, uncontrolled eye movement).

This time, fearing a possible stroke, staff admitted Tracey to a stroke ward and prescribed aspirin and clopidogrel, an anti-clotting drug.

Tracey eventually had an MRI scan 48 hours later which this time found a small clot in the brainstem (the structure that connects the brain and spinal cord, and regulates vital body functions) and this had caused a stroke.

Thankfully, it wasn’t large enough to warrant surgery and she was given clot-busting drugs to dissolve it.

‘It was still a shock – I was only 42 – I gave up smoking 11 years before and didn’t have high blood pressure and had actually just lost 2st,’ says Tracey.

‘So I didn’t have any of the traditional stroke risk factors.’

More than 100,000 people a year in the UK have a stroke, where the blood supply to the brain is blocked by a clot, or a bleed on the brain.

One in four occur in people of working age, including 400 children.

Up to half of strokes in younger people – those under 50 – are cryptogenic, meaning they have no apparent cause.

A recent study in the journal Stroke has shed new light on what might be the possible cause of some cryptogenic strokes in younger people.

Researchers at Helsinki University Hospital found that adults younger than 50 had more than double the risk of a stroke as a result of non-traditional stroke risk factors, such as being a migraine sufferer, rather than traditional stroke risk factors such as high blood pressure and smoking.

As Professor Pankaj Sharma, a consultant neurologist at Imperial College London Hospital, explains: ‘In the last ten to 15 years it’s become increasingly recognised that migraine is a risk factor for stroke.

‘The stroke risk tends to be higher with classical migraine, also known as migraine with aura [which includes symptoms such as visual disturbances or numbness and tingling], rather than common migraine without aura.

‘Classical migraine doubles or triples your risk of stroke,’ says Professor Sharma.

‘That sounds horrendous but the risk of having a stroke in your 20s is very small – so even if its double the risk it’s still a small risk, it’s about the same stroke risk associated with taking the combined contraceptive pill.’

Exactly how migraines might trigger a stroke remains unclear.

But Professor Sharma says they may be connected to a condition called a patent foramen ovale (PFO) or a ‘hole in the heart’, where a small gap between the two chambers of the heart doesn’t fully close after birth.

‘A hole in the heart is one of the most common causes of stroke in younger people and one of the first things I look for in my patients,’ explains Professor Sharma.

‘We are all born with these, but when we’re born these close up when a baby cries and takes its first breath.

‘However, in one in four people the hole doesn’t close, and this puts them at slightly higher risk of stroke.’

One theory is that PFOs may cause migraines because they throw off micro-bubbles and microemboli (tiny clots) into the brain, which – whilst not large enough to cause a stroke – may precipitate a migraine attack.

‘We do find that if we close a PFO with surgery in someone who has had a stroke or a mini-stroke [a transient ischemic attack or TIA, where the blood supply to the brain is temporarily interrupted], a lot of those people report that their migraines improve,’ explains Professor Sharma.

When Tracey’s heart was investigated with an echocardiogram in December last year, this revealed a previously undiagnosed PFO – and she believes this may have contributed to her severe migraines and stroke.

She is now waiting for doctors to decide if she is appropriate for surgery to close the PFO.

Professor Sharma says another cause of stroke in younger people is artery dissection in the neck – these can be ruptured by trauma such as that caused by playing rugby or football, or ‘beauty parlour syndrome’, sitting at a sink in the hairdressers with your neck bent back (although this is rare).

‘There is usually a preexisting weakness in the artery there in those cases,’ he says.

The stroke damaged Tracey’s eyesight – she had double vision for three months afterwards and at one point worried she’d have to give up nursing. ‘I was devastated to be so badly affected at such a young age,’ she says.

But her sight has since been improved after doing special eye exercises.

Professor Sharma says classical migraine symptoms can mimic those of a stroke – for instance, weakness down the left side and speech disturbance – so it can be extremely difficult for the general public to tell the symptoms apart.

‘My advice is if you are in any doubt whether it’s a stroke or a migraine the first time it happens, then you need to call 999 and get checked out – there is so much more we can do to treat stroke now if we see people as soon as possible.

‘We would rather reassure you that it isn’t a stroke than let you risk your symptoms going untreated in time.

‘Once you’ve had one migraine attack like that you’ll recognise the symptoms if you have subsequent ones.’

Tracey says: ‘There are so many others like me I’ve read about on the online forum of Different Strokes, a charity for younger stroke patients, who say they were sent home as a CT scan didn’t show up their stroke.

‘We should be assessed with MRIs promptly. Looking back, I wonder if my worsening migraine attacks might have been a warning sign of my PFO and that I was at risk of a stroke.’

differentstrokes.co.uk