| Despite the ongoing efforts of medical scientists to | | | | seven different subtypes. The first subtype of |
| reveal the factors responsible for causing multiple | | | | multiple sclerosis is the relapsing-remitting multiple |
| sclerosis, the exact reasons why the disorder occurs | | | | sclerosis (RR MS), the most common form of the |
| in otherwise healthy persons remain unknown. | | | | autoimmune disorder. According to statistics, more |
| Although various factors are suspected to trigger the | | | | than 80 percent of all multiple sclerosis cases are of |
| occurrence of multiple sclerosis (viral or bacterial | | | | the relapsing-remitting subtype. This subtype is |
| infections) or to facilitate its progression (genetic | | | | characterized by phases of symptomatic remission, |
| dysfunctions and various external, environmental | | | | followed by phases of relapse (characterized by |
| factors), medical scientists haven’t yet reached a | | | | sudden intensification of symptoms). The duration of |
| consensus regarding the exact causes of the | | | | the phases of relapse and remission vary from a |
| disorder. | | | | patient to another, lasting anywhere from several |
| Multiple sclerosis is a type of autoimmune disorder, | | | | weeks to several years. |
| involving abnormal activity of the immune system, | | | | The second subtype of multiple sclerosis – |
| which turns against healthy body cells instead of | | | | primary-progressive multiple sclerosis (PP MS) |
| fighting against intruding infectious agents. The body | | | | accounts for around 20 percent of all multiple |
| cells which are primarily targeted by the immune | | | | sclerosis cases. The major characteristics of this |
| system in the case of patients with multiple sclerosis | | | | subtype are gradual progression of the disease, with |
| are nerve cells. In fact, the autoimmune response of | | | | very short phases of remission. The third multiple |
| the body doesn’t destroy nerve cells directly; | | | | sclerosis subtype is similar to the PP MS subtype and |
| the dysfunctional immune system produces antibodies | | | | is called secondary-progressive multiple sclerosis (SP |
| that destroy myelin, a protein that wraps around the | | | | MS). Patients with primary-progressive multiple |
| cells of the nervous system, facilitating the | | | | sclerosis have 50 percent chances to eventually |
| communication between the central nervous system | | | | develop secondary-progressive multiple sclerosis. |
| (CNS – brain and spinal cord) and peripheral | | | | The fourth subtype of multiple sclerosis is called |
| nerves and vice versa. | | | | progressive-relapsing multiple sclerosis (PR MS) and is |
| At first, multiple sclerosis causes impairments only at | | | | characterized by gradual progression with frequent |
| the level of the central nervous system. In more | | | | phases of symptomatic exacerbation. The fifth |
| advanced stages of progression, multiple sclerosis can | | | | multiple sclerosis subtype alternates between the |
| involve virtually any innervated region of the body | | | | primary-progressive, secondary-progressive and |
| (any part of the body that contains a network of | | | | progressive-relapsing forms of the disease. The sixth |
| nerves). Without proper medical treatment - which is | | | | multiple sclerosis subtype is benign multiple sclerosis, |
| most effective when administered in early stages of | | | | characterized by an initial symptomatic flare which |
| disease – multiple sclerosis can cause a variety of | | | | can be followed by slow or no progression at all. The |
| disabilities and sometimes even death. | | | | seventh and last multiple sclerosis subtype is also |
| Depending on its patterns of progression, as well as | | | | very rare. It is called malignant multiple sclerosis and |
| the intensity and frequency of its generated | | | | involves rapid progression and very intense |
| symptoms, multiple sclerosis can be categorized in | | | | symptoms. This subtype is in most cases deadly. |