The number of people living with multiple sclerosis (MS) in England has more than doubled in the last 20 years, with approximately 190,000 individuals now diagnosed with the incurable neurological condition, according to recent research published in JAMA Neurology. MS cases are increasingly being diagnosed later in life, challenging the long-held perception of the disease primarily affecting young adults.
Heather Wills, 49, initially dismissed the numbness in her big toes as a result of prolonged standing and wearing uncomfortable shoes. However, after a week, her GP identified an issue with her ability to feel light touch, leading to a referral to a neurologist. Seven months later, the numbness had spread up her shins, prompting concern. A neurologist initially suggested a vitamin B12 deficiency, but tests ruled this out. Nerve conduction tests also yielded normal results.
By the fourth year of experiencing symptoms, the altered sensation had reached Heather's thighs and hips. An urgent MRI scan revealed gray areas on her spinal cord, and a subsequent lumbar puncture confirmed a diagnosis of MS. Wills noted a sense of relief that it was not cancer, a possibility that had been discussed.
MS occurs when the immune system mistakenly attacks myelin, the protective sheath around nerves in the brain and spinal cord. This disruption impedes communication between the brain and the body, leading to symptoms such as blurred vision, numbness, fatigue, muscle weakness, and difficulties with balance and walking. The most common form, relapsing-remitting MS, involves periods of flare-ups followed by remission.
Diagnosing MS can be challenging due to the absence of a single definitive test. MRI scans can detect lesions in the brain or spinal cord, and a lumbar puncture can identify specific antibodies. While treatments have improved, with medications like ocrelizumab and natalizumab available, MS can still lead to significant disability. Research indicates that individuals diagnosed with MS after age 50 may face a higher risk of disability progression compared to those diagnosed earlier, potentially due to the body's reduced ability to repair damaged myelin with age.
Several factors are thought to contribute to the rising incidence of MS. Wider access to MRI technology allows for the detection of milder cases that might have previously gone unnoticed. Professor Ruth Dobson, a professor of clinical neurology at Queen Mary University of London, suggests that improved diagnostic capabilities play a role. Additionally, advancements in treatments have led to people living longer with the condition, moving from dying from MS to dying with MS.
Beyond diagnostic improvements, lifestyle and environmental factors are under scrutiny. Potential culprits include obesity, smoking, air pollution, diets high in ultra-processed foods, and alterations in gut bacteria. A significant area of research focuses on the Epstein-Barr virus (EBV), the cause of glandular fever. A 2022 study in Science found that individuals were 32 times more likely to develop MS after contracting EBV. While EBV infection rates haven't necessarily increased, people are contracting it later in life, often in adolescence or adulthood, due to factors like better hygiene. This delayed infection triggers a stronger immune response, significantly raising the risk of MS. Professor Paul Farrell, an emeritus professor of tumour virology at Imperial College London, believes that certain types of B-cells, present from adolescence onwards, can cross the blood-brain barrier after EBV infection and initiate the attack on myelin.
Low levels of natural sunlight, particularly in regions like Scotland, have also been linked to MS. Sunlight is crucial for vitamin D production, which helps regulate the immune system. However, sunlight alone does not explain all geographical variations in MS rates. Genetic factors, such as the presence of the HLA-DRB1*15:01 gene, which is more common in Scotland, may influence the immune system's reaction to infections like EBV, increasing the likelihood of autoimmune attacks on myelin.
Adolescent or early adulthood obesity and smoking can also approximately double the risk of developing MS. Wills, who was diagnosed in 2022, experienced leg muscle tension and spasms, which were managed with medication. Despite the limitations imposed by MS, she finds support within a community of fellow patients and emphasizes the importance of seeking medical attention for persistent symptoms, urging others not to dismiss potential warning signs as simply part of aging.