Potential cause of MS: Environment

Researchers have noticed an increased pattern in cases of multiple sclerosis in countries that are located the furthest from the equator. Sun exposure is one way for the body to get vitamin D. The correlation between decreased sun exposure and increased levels of MS has led some to believe that a vitamin D deficiency may play a causal role in multiple sclerosis. 

Vitamin D is extremely beneficial for your immune system. People who are closer to the equator are naturally exposed to more sunlight and as a result, their bodies may be able to produce more vitamin D.

Research published in the journal Neurology in October 2017 seems to confirm this correlation. The study used serum samples from over 800,000 women in the Finnish Maternity cohort. Using an an adjusted conditional logistic regression, the researchers found that an increase in vitamin D [25(OH)D — also known as calcifediol or 25-hydroxyvitamin D] of 50 nmol/L was associated with a 39% reduced risk of multiple sclerosis.

The researchers concluded: “These results directly support vitamin D deficiency as a risk factor for MS.”

 

Other environmental factors may also be risk factors for MS. There has also been evidence showing that smoking may play an important role in the development of the disease. Research has shown that smoking may increase a person’s risk for developing MS and it is also associated with a more severe and rapid progression of the disease.

Potential MS cause: Infectious triggers

The initial exposure to a wide range of viruses, bacteria, and other microbes that occur during childhood are generally known to cause inflammation and demyelination (damage to the myelin sheath). This means it is possible for a virus or other form of infection to trigger the development MS.

Dozens of bacteria and viruses that have been investigated to determine if they may lead to the onset of MS, including:

• Human herpes virus-6 (HHV-6)
• Measles virus
• Epstein-Barr virus (EBV)
• Canine distemper
• Chlamydia pneumonia

To date, none of the potential causes studies have been proven as a definitive cause of MS.

 

Potential MS cause: Genetic factors

Although MS is not consider to be hereditary disease, research has shown that having a first-line relative, such as a sibling or parent with multiple sclerosis may significantly increase a person’s risk of developing the disease. In fact, one study found that a child has 10-times the risk of developing MS if both of parents have it.

Studies have shown there is a significantly increased prevalence of certain genes in a population with higher rates of MS. Many researchers believe that people with multiple sclerosis are born with a genetic predisposition to certain, unknown environmental agents. Then, upon exposure to the trigger, the body begins the immune-mediated response.

Research published in June 2016 worked to identify the gene mutation responsible for the onset of multiple sclerosis. Identifying a mutation in the gene: NR1H3 — the researchers found that there was a 70% chance of developing MS when the mutation was present.

Disproved theories on the cause of MS

While there is still speculation into the mechanisms leading to the onset of multiple sclerosis, some theories have been disproved. Some of these disproved theories include:

• Living with dogs or small pets
• Having allergies
• Experiencing physical trauma
• Exposure to heavy metals such as lead or mercury
• Consuming aspartame

Is multiple sclerosis an autoimmune disease?

According to the National Multiple Sclerosis Society, multiple sclerosis is an immune-mediated disease. There is discussion among experts whether it is accurate to call MS an autoimmune disease (such as lupus, Crohn’s disease, and rheumatoid arthritis).

In an autoimmune disease, the body’s immune system misidentifies a normally occurring antigen in the body and responds to it as if it were a foreign invader. While the same type of immune response occurs for people with multiple sclerosis, no antigen has been identified yet.

Signs & symptoms of multiple sclerosis

People with multiple sclerosis experience a variety of symptoms and symptoms can vary significantly from one person to another. In fact, depending on the location of the nerve fibers that have been affected, the symptoms may even change in severity day-to-day.

Two of the most common symptoms of multiple sclerosis are extreme fatigue and difficulty walking. Other symptoms of MS include:

• Tingling or pain in various parts of the body
• Sensations of an electric-shock that may happen with certain movements of the neck, especially while bending forward
• Weakness or numbness in one or more of your limbs
  • Often occurs on one side of your body at a time, or in the trunk and legs
• Prolonged double vision
• Partial or complete vision loss
  • Typically in one eye at a time
• Slurred speech
• Dizziness
• Body tremors
• Lack of coordination and/or unsteady gait
• Problems with bladder and bowel functions
• Muscle spasticity
• Cognitive issues involving memory, concentration and problem-solving skills
• Acute or chronic pain

Course of multiple sclerosis

MS often presents itself as a relapsing-remitting disease. Symptoms may be present for a few days or weeks at a time. Then, following a relapse into high disease activity, the symptoms may partially, or completely improve.

Remission (the time between flare ups of the disease) may last months, or even years for some people. The cyclical nature of the disease and the range of symptoms possible combine to make MS incredibly unpredictable.

Relapsing-remitting MS can turn into secondary-progressive MS. In secondary-progressive MS (SPMS), the symptoms are often worse and there is little or no time remission. Previous research showed that 50% of people would develop SPMS in 10 years, and 90% of people would develop it in 25 years. But, new treatments are being developed to slow or stop this progression.

Although MS is thought to be an autoimmune disorder, it is not like catching the flu or a cold. Multiple sclerosis is an incurable, lifelong disease and the symptoms can range from mild to completely disabling.

If you suspect you may have any of the symptoms of multiple sclerosis, speak with your physician, or a neurologist, as soon as possible.