I thought my numb big toes were caused by always being on my feet. Four years later, I was told I had an incurable disease that’s on the rise in women over 40. Don’t ignore the warning signs

At first Heather Wills assumed the numbness she had suddenly developed in both her big toes was nothing serious.

‘Being a busy mum, I thought it was caused by standing for long periods, carrying my young daughter and wearing heels that I wasn’t used to,’ the mother of two, then 49, recalls.

But after a week she went to her GP, who gave her a series of tests, including one that checked her reflexes.

‘She said there was definitely something amiss with my ability to feel a light touch,’ says Heather, who lives with her husband, Nick, a teacher, and their children, aged 18 and 13.

Heather was referred to a neurologist, who she saw seven months later. By then, the numbness had moved up to her shins.

‘I was getting quite concerned,’ she says. ‘I asked the neurologist if it could be multiple sclerosis (MS), because my aunt had it. But she said, “No, you’re too old for that”.’

Instead, the neurologist thought Heather had a vitamin B12 deficiency, as the nutrient plays a key role in nerve function. However, blood tests ruled this out. The results of nerve conduction tests, which use electrical impulses to check nerve function, were also normal.

‘As the altered sensation was moving up my legs I began to get really scared,’ says Heather.

‘It was just an abnormal sensation; there was no loss of movement or control so, at that point, it hadn’t stopped me doing anything – but what if it continued up to my arms? I love doing crafts, cooking and gardening, and if this progression continued, would my ability to do these things be affected?

‘It was a very scary time. Looking back, the one thing it did affect was my energy levels. Nick used to refer to it as me “hitting the wall” of an evening.’

By the fourth year of her symptoms, the sensation had moved up to her thighs and hips.

‘I emailed the neurologist, who said because of my background as a physio she knew I wouldn’t be contacting her without good reason,’ says Heather, who was given an urgent MRI scan.

‘Straight after my scan, the neurologist showed me grey areas on my spinal cord on the screen,’ she says.

She underwent a lumbar puncture and the following week was told she did, in fact, have MS.

‘I actually felt relieved that it wasn’t cancer, because at one point there had been talk of a possible tumour,’ says Heather.

Heather is one of a growing number of people in the UK now living with MS: cases in England have more than doubled in 20 years, with around 190,000 now thought to have the incurable disease, according to new research in the journal JAMA Neurology.

Possible factors behind the worrying rise include a very common virus which causes the so-called kissing disease, glandular fever. A Scottish heritage may be another factor, as is being overweight.

For years it was seen as a disease of young adulthood, striking most often between the ages of 20 and 40 – as this is when the immune attack on the nerves first starts – but new evidence shows that picture is changing.

Separate research suggests that MS symptoms are increasingly beginning later in life: the Journal of Neurology, Neurosurgery and Psychiatry reported, in 2022, that the proportion of patients whose symptoms began after 50 rose from around 1 per cent before 1991 to almost 10 per cent after 2010.

MS occurs when the immune system mistakenly attacks myelin, the protective coating around nerves in the brain and spinal cord.

This disrupts messages between the brain and the rest of the body, causing symptoms such as blurred vision, numbness, fatigue, muscle weakness, poor balance and difficulty walking.

The most common form of MS, the type Heather has, is relapsing-remitting MS, which causes flare-ups followed by periods of recovery or remission.

MS can be difficult to diagnose as there is no single test for it, so it can be easily missed.

MRI scans can reveal scars in different parts of the brain or spinal cord. This may be followed by a lumbar puncture, which tests fluid from around the spine for antibodies (a sign that the immune system has been abnormally active in the area).

When MS starts after 50, it can also cause more lasting disability such as poor balance and difficulty walking, with some people needing a wheelchair.

A study of 888 patients, published in the Journal of Neurology in May, found those whose MS began after 50 had a 55 per cent greater risk of their disability worsening between relapses – possibly because as we get older, the brain and spinal cord are less able to replace damaged myelin.

So why are far more people now living with MS?

One reason is that doctors are finding cases that would once have been missed.

Wider access to MRI scans means they can now see the tell-tale patches of damage MS leaves in the brain and spinal cord, allowing them to diagnose milder cases that might have gone undetected ten or 20 years ago, says Ruth Dobson, a professor of clinical neurology at Queen Mary University of London.

The good news is that treatments have improved, too.

These include ocrelizumab, which removes the cells involved in the attack on myelin; and natalizumab, which stops damaging immune cells crossing from the blood into the brain and spinal cord.

‘People now die with MS rather than dying from MS,’ says Professor Dobson.

Yet better diagnosis and longer survival may not entirely explain the increase.

‘Similar to many autoimmune conditions, MS is becoming more common,’ says Professor Dobson.

Possible culprits include obesity, smoking, air pollution, diets high in ultra-processed food and changes to the gut bacteria that help train the immune system.

Another possible explanation is the Epstein-Barr virus (EBV), which causes glandular fever and symptoms such as fever, a severe sore throat and overwhelming fatigue that can last for weeks or months. (It is passed on via saliva, hence glandular fever is often referred to as the kissing disease.)

A landmark 2022 study in the journal Science, which followed more than ten million members of the US military, found people were 32 times more likely to develop MS after catching EBV than those who had not yet been infected.

While EBV itself is not becoming more common, children are catching it later: the delayed infection is a result of better hygiene and less crowded homes, meaning more of us catch it as teenagers or adults.

Infection at that age triggers a much stronger immune response – and this carries a far higher risk of MS.

‘If a person does not become infected when very young but gets an infection as a late teenager or adult, they then have an increased risk of developing MS later in life,’ says Paul Farrell, an emeritus professor of tumour virology at Imperial College London.

EBV infects B-cells, a type of white blood cell that makes antibodies, and remains hidden inside them.

Professor Farrell believes that when infection happens later in life, infected B-cells cross the blood-brain barrier (the protective filter around the brain) and trigger the attack on myelin – the key may be a type of B-cell that appears from the teenage years onwards. The virus can infect these ‘adult B-cells’, which are able to cross the blood-brain barrier.

Scientists also believe that growing up in parts of the world low in natural sunlight can cause MS – Scotland, for example, which has the highest rates in Britain. Sunlight is vital for the body to produce vitamin D, which helps keep the immune system in check and stops the body’s defences turning on its own tissues.

Professor Dobson suggests vitamin D levels at birth, which partly reflect the mother’s levels during pregnancy, may affect future risk.

Sunlight could protect against MS in another way: UV rays act on immune cells in the skin, increasing the T-cells that can reduce inflammation and help stop the body’s defences attacking its own tissues.

But lack of sunlight alone cannot explain Scotland’s unusually high rate of MS.

‘Other countries similar to us for sunlight, for example Scandinavia, have less MS than us, so it is not simply the amount of sunlight,’ says Anna Williams, a professor of regenerative neurology at the University of Edinburgh.

She suggests that genes that control the immune system can influence how strongly it reacts to infections such as EBV.

People with the HLA-DRB1*15:01 gene – more common in Scotland – are more likely to mount the autoimmune attack that damages myelin.

Smoking or being obese in adolescence or early adulthood also roughly doubles the risk of developing MS, adds Professor Dobson.

Not long after Heather was diagnosed in 2022, she started suffering from increased tension in the muscles in her legs and was prescribed baclofen to help relax them.

But after a few months, she started getting spasms at night in her legs. This also happened ‘when I got out of bed in the morning,’ she says.

‘I was so frightened it was going to stop me driving – catastrophic for where we live, in a semi-rural village. I needed to drive to school, to go shopping, to go anywhere.’

But after she was prescribed clonazepam the spasms stopped.

Heather says: ‘I always have the sensation of my legs being partly numb – it sometimes also feels like my legs have been shrink-wrapped because the skin feels tight.

‘The local hospice has been great at providing services and I’ve been referred to a lady who does massage. She has discovered knots in my leg muscles that I didn’t even know were there; after she releases them, I feel so much better.’

Heather says while MS has imposed limitations on what she can do, ‘it has also given me a group of friends [other MS patients] who I would otherwise never have had the chance to meet.

‘I count myself very fortunate to have been diagnosed relatively quickly. Some people spend years before finally getting the MS diagnosis. My thought was that once I knew what it was we could get on and start to treat it.

‘But I do think that if diagnosis had been sooner, the damage that’s been done would have been less. However, diagnosis isn’t straightforward. I’m thankful that my GP referred me so quickly after I presented to her with symptoms.

‘The neurologist who dismissed me as being too old for MS acknowledged she was wrong, and hopefully my experience will encourage others to seek help. Don’t assume it’s just part of getting older, and don’t be afraid to ask questions if something doesn’t feel right.’

Case study interview by JULIA SIDWELL

For information and support, visit mstrust.org.uk