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What is multiple sclerosis? It is not quite simple to give exact information on multiple sclerosis. In spite of the great progress in research, MS has remained a puzzle with many questions since this disease was first described in 1868.

We still do not know what exactly causes this disease and we are also still unable to completely cure this disease. The course of the disease varies greatly among individual patients. This is why MS is sometimes called “the disease of a thousand faces”.

What is MS?

Multiple sclerosis (MS) is a chronic inflammatory disease of the central nervous system (CNS) which involves progressive degeneration and a significant immunological component in its pathogenesis. It is most often a neurological disease causing disability of young persons of a productive age. Clinically, it is most often characterised by repeated episodes (attacks) of neurological symptoms. Occurrence of this is based on autoimmune inflammation in the central nervous system (brain and spinal cord). The duration of the attacks is at least 24 hours but mostly it is days, less frequently weeks. Partial or almost complete recovery to a normal condition follows after the attacks.

A simplified answer to the question “What is MS?” is given to us by its very definition. The word “sclerosis” originates in Greek and denotes “hardened, scar tissue”. “Multiple” then means “multiplied, diverse”. Repeated episodes (attacks) of MS thus cause formation of many “scars” in the central nervous system. Through various mechanisms, the structure and function of white and grey brain matter are disrupted. In the initial stage of the disease, the inflammatory changes are at the forefront; later on, as the disease progresses, the changes tend to be more of a neurodegenerative nature. In this way, the nerve tissue gradually gets permanently damaged and a number of function systems are irreversibly neurologically affected. The attacks of the disease may occur at any time and may affect any area of the CNS; that is how diverse the clinical picture of the disease is.

What actually happens during multiple sclerosis

Nerve fibers transmit the signals coming from the brain through the spinal cord to the entire body. Myelin, a white substance, wraps the nerve fibers similarly like a bark protects a tree. It insulates them, which increases the transmission speed of electric signals. 

In patients with MS, their own immune system, which is normally supposed to fight infections and harmful influences, considers myelin to be an alien substance by mistake. It attacks it and destroys it. As a result, myelin disintegrates in many places of the brain and the spinal cord to a varying extent. This causes impairments resulting in a great diversity of clinical pictures because the neural pathways whose myelin is degraded unpredictably vary in each patient. This is why there is no single clinical picture for MS.

In most cases, the inflammation itself only results in temporary function failures. Nevertheless, it subsides, it can leave scars, which block the transmission of a nerve impulse. The functional capacity in these places has been permanently destroyed.
Today, we know that from the very beginning of the disease, not only myelin is being damaged but that also neural fibers (axons) are destroyed to a varying degree. These neural fibers are function carriers and are not replaceable in the CNS. The degree of damage to these fibers then determines the residual damage after acute attacks and the overall degree of disability of the patient.

More: Havrdová E. et al., Roztroušená skleróza v praxi, Galén, Praha 2015.»