Multiple Sclerosis (MS) is a chronic illness which affects the central nervous system (CNS); the brain and the spinal cord. Disease onset is most common between the ages of 20-40 years and it is twice as common among women compared to men. More than 15,000 individuals are living with an MS diagnosis in Sweden and over 600 people in Sweden are diagnosed with MS each year. The national prevalence is almost 2 per 1,000 inhabitants.

In MS, the body’s own immune system is attacking and breaking down the nervous system. This break down of the nervous system causes scaring on the connective tissues in the brain and spinal cord hindering the CNS from communicating properly. This scaring can lead to decreased physical and cognitive functions.

The symptoms of MS vary depending on which parts of the CNS are affected. It is common that symptoms fluctuate over time and peaks in symptom outbreaks are often followed by periods of fewer or no symptoms.

The extent to which the symptoms retrieve vary and it is difficult to predict the symptom development for one individual. The first symptoms often include ocular inflammations and loss of sensitivity and “tingling” in the muscles. Other common symptoms include fatigue, reduced mobility, dizziness, bladder and bowl difficulties, sexual dysfunctions, reduced cognitive ability and mood swings. 

There are several different subtypes of MS which differ in disease progression. The symptoms may increase constantly over time or occur in intervals where episodes with many difficult symptoms are followed by months or even years without symptoms. The physical symptoms may disappear completely between episodes; however some irreversible neurological damage will inevitably occur as the disease progresses.

There are geographical differences in the prevalence of MS. The disease is five times more common in areas with colder climates such as northern Europe, Canada, northern America and southern Australia than in countries with tropical climates.

MS is a chronic disease and there is still no cure. New inhibitor drugs have however been developed which effectively slow down the progression of the disease. The drugs reduce episode frequency as well as allow the patient to retain more of his/her neurological functions after symptomatic episodes than was previously possible.

Causes of MS

In MS, the body’s own immune system is attacking and breaking down the protective fatty tissue which surrounds the nerve fibers in the CNS. This break down of the fatty tissue causes damage on the nerve fibers which in turn hinders the flow electrical signals sent through the nerve fibers used in communication within the CNS. This ultimately decreases physical and cognitive function in the body. MS is assumed to be an auto-immune disease, however the causes of MS are yet unknown. Ongoing studies, such as EIMS, aim to increase our understanding of the underlying factors behind the development of the disease.

Through genetic studies it has been found that individuals with a specific tissue type (specifically tissue cells with the HLA-DR2 surface molecule) have an increased risk of developing MS. This specific tissue type is more common in populations indigenous to the northern countries in Europe and North America. A variant of this tissue type has been assumed to be the most important genetic risk factor for developing MS. It is twice as common among MS patients as the general Swedish population.

Studies done on identical twins have shown however that genetic factors only explain a portion of the risk factors involved in the development of MS. Environmental factors also play a significant role. Research results indicate that specific gene variants in combination with certain environmental factors increase the risk of developing MS.

Environmental factors that have been identified as having an effect on the risk of developing MS include mono infections caused by the Epstein-Barr virus (EBV), sun exposure, vitamin D levels, working shifts with irregular hours and smoking.

To read more about our published research results, click here.