Multiple Sclerosis: Symptoms, Causes & Risk Factors

Multiple sclerosis (MS) is a condition that affects the brain and spinal cord. The body’s immune system attacks the protective covering of nerve fibers, which then affects the way the electrical messages flow within the brain, and from the brain to the rest of your body. It causes damage to the nerves, which causes scarring. Learn more about how MS affects the body here.

Symptoms of Multiple Sclerosis

In people with multiple sclerosis (MS), areas of inflammation caused by white blood cells appear as white spots on the brain and spinal cord. If the spots are in areas that perform a very obvious function, then even the slightest damage will cause noticeable symptoms. For example, if the nerves to the eye become even slightly inflamed, a reduction in vision will be noticed. Similarly, if inflammation in the spinal cord occurs in the nerves that carry pain, it will immediately be felt. However, if the inflammation is in the areas that process memory or judgment, or in the fibers that link-up to such important areas, it may go totally unnoticed.

Inflammation and demyelination usually develop over hours or days (it does not occur abruptly like a stroke). It usually then persists for several days or weeks, and then subsides and recovers. The recovery happens because the immune system decides to stop attacking the nerves. The nervous system then starts repairing itself, known as ‘remyelination’, and function may return to normal.

An episode of new inflammation is called a ‘relapse’ or ‘attack’. Symptoms of a relapse depend on the area that is inflamed and there can be many. They vary from person to person and are hard to predict. They may come and go and can affect different people at different times. Some symptoms are responsive to treatment while others are more difficult to manage. As MS affects the nerves of the brain and spinal cord, it can affect almost any part of the body and its functions.

Whilst most people won’t experience all the common symptoms of MS, it is important to recognize the signs to ensure an accurate diagnosis as soon as possible, and to rule out other possible medical complications.

Common symptoms of MS

• Loss of vision:this can include blurred vision or poor color contrast. Sometimes this is associated with eye pain due to inflammation of the optic nerve.
• Double vision:this occurs when inflammation in the stem of the brain causes a misalignment of the eyeball; one eye may turn in or out and the brain ends up ‘seeing’ two images which causes double vision.
• Lhermitte’s symptom:this is a bending of the neck, which causes an uncomfortable tingling that spreads down the body. It happens when inflammation occurs in the spinal cord within the neck.
• Weakness:this occurs in the muscles of the legs or arms due to inflammation in the spinal cord or brain. It is important to remember that the muscles themselves remain normal.
• Walking difficulty:this may be due to multiple factors, including loss of balance, fatigue, and actual weakness.
• Numbness:may be experienced in the face, arms or legs. These areas may begin to feel different and sensory loss may become blunted and not fully absent.
• Paresthesia or ‘tingling’:this can be uncomfortable or only be mildly noticeable.
• Stiffness:also called spasticity, this is a difficulty in moving limbs or flexing joints. Often it is associated with involuntary muscle spasms or jerks in the limbs.
• Dizziness:a feeling of being off-balance, or that everything around you is spinning (vertigo)
• Bladder/bowel problems:this can include urgency, frequency, and sometimes incontinence. Sometimes the opposite can occur in patients retaining for a long time due to a lack of sensation. It is caused by inflammation in the spinal cord.
• Sexual problems:in men this can be in the form of loss of erection. Women may notice a loss of sensation. Both are due to inflammation in the spinal cord.
• Pain:this can be described as a dull ache or burning, while some patients may experience chronic pain. This pain is usually in the arm or leg; whole body pain is very unusual in MS.
• Tremor:an uncontrollable shaking which typically occurs in the arm when reaching out for objects
• Cognitive changes:these can include forgetfulness, being slower to understand new information, or losing the ability to multitask.
• Emotional changes:these may be caused by the stress of MS symptoms, or due to changes in the brain. They include depression and anxiety, which is most often due to the stress of dealing with the diagnosis of a chronic illness.
• Fatigue:this is more severe than tiredness, and affects many people with MS. It is often the most obvious symptom in someone who otherwise isn’t limited in activity.

Less common symptoms of MS

Since MS affects any part of the brain or spinal cord, lots of other symptoms are possible, but are usually less common. These include trigeminal neuralgia (an electric shock-like pain in the face), seizures, and problems with speech, swallowing, breathing, and hearing.

What causes Multiple Sclerosis?

We still don’t know for certain what causes MS. Experts believe that there may be a combination of factors that make MS more likely to develop, rather than a single cause. These risk factors are things that we are all exposed to every day, but only a small number of people will go on to develop MS. Doctors aren’t able to predict who will and won’t get the disease.

Immunologic factors

It is widely believed that MS is an autoimmune disease. This means that our body’s own immune system, which is responsible for fighting infection, starts to attack healthy cells in a faulty immune response. When someone has MS, the immune system targets something called ‘myelin’, a fatty protein that covers the nerves in our brain and spinal cord. This is called demyelination. When this happens, our nerves can’t conduct electrical impulses properly. The messages from the brain can’t travel along the nerves smoothly, causing a delay or complete interruption.

In the early stages of MS, the body can repair this damage to some degree, and replace the myelin so messages can still travel along the nerves. This is called remyelination. The brain can also reroute messages. Over time though, the loss of myelin leaves nerves exposed and more at-risk of permanent damage.

Other possible risk factors for MS

Genetic factors

MS is not an inherited condition, which means that it is not hereditary or passed on from other family members. However, some people may have specific genes that make them more likely to develop the disease, so there is a genetic risk that it might be inherited. For example, in identical twins, if one has MS, then there is a much higher chance that the other will develop it too. While several members of the same family may have MS, having the specific genes does not increase risk of other family members having the condition and other risk factors are needed to trigger the onset.

Infection

Research has shown that while an infection does not cause MS, it can act as a trigger, which sets off a number of events within the body which may develop into MS over a long period of time. We still don’t know which viruses can cause this trigger, or the exact chain of events that lead to MS, but scientists are exploring the link with Epstein-Barr virus (EBV), measles, and human herpes virus-6.

Environmental factors

Studies have revealed that there may be several environmental factors that increase the chance of MS developing. These include:

• Vitamin D: This is produced by the body when our skin is exposed to sunlight. Populations living further from the equator, where there is less sunlight, have more cases of MS, so lack of sunlight may contribute to the development of the disease. Even if you live close to the equator or in areas with good sunlight like the Middle East, if you remain mostly indoors or covered up, vitamin D levels can be very low. Supplemental vitamin D to maintain adequate levels is therefore important.
• Smoking: smoke has numerous toxins that not only damage the lungs, but the nerves too. Those who smoke are also likely to develop more severe symptoms of MS. Smoking also causes damage to the blood vessels in the brain, which appears as white spots. High blood pressure and cholesterol can also contribute to such spots. All of these factors can contribute to the progression of MS, so it is crucial that this risk factor is controlled, and MS patients stop smoking.

Who gets Multiple Sclerosis?

While doctors can’t predict who will get MS, they have found that there are certain patterns in the distribution of the disease that might help us understand what causes it. This is called epidemiology. Factors affecting epidemiology include:

• Gender: MS is more common in women than men, by up to three times, suggesting female hormones may play a role.
• Age: MS is most commonly diagnosed between the ages of 20 and 50, but it can also occur in children and older adults.
• Geography: MS is more common in parts of the world that are further from the equator.
• Ethnicity: Caucasians from North Europe are most at risk of developing MS, followed by African American women. But MS can occur in all races, including people from the Middle East.

The number of people being diagnosed with MS is increasing and experts aren’t sure why. While it may be down to increased awareness of the disease and more sophisticated diagnostic techniques, there may be other factors involved that are not yet clear.