Multiple sclerosis (MS) is an immune-mediated inflammatory disease that attacks myelinated axons in the central nervous system, destroying the myelin and the axon in variable degrees and producing significant physical disability.
To understand what is MS, it is critical to understand the structure of neurons. Axons are key parts of a neuron, they transfer electrical signals as an action potential from the neuron cell body to its axon terminal where it synapses with another neuron.
To increase the speed of electric signals, an axon is covered with a myelin sheath or myelinated throughout its length. Myelin sheath is a multilayer of proteins and lipids.
Multiple sclerosis causes
Multiple sclerosis causes are complex and include genetic predisposition along with environmental factors such as exposure to infectious agents, vitamin deficiencies, and smoking, however, the etiology and pathogenesis of MS are still unclear.
MS begins with the immune system attacking nerve fibers and myelin sheathing in the brain and spinal cord. This attack causes inflammation, leading to the destruction of nerve cell processes and change in electrical signals in the brain.
Some individuals may have mild symptoms, while others may lose their ability to write, speak or walk. Nerve lesions can lead to visual disturbances, ataxia, fatigue, troubled thinking, and emotional instability.
MS subtypes are considered important during prognosis and treatment: relapsing-remitting MS (RRMS), primary progressive MS (PPMS), secondary progressive MS (SPMS), progressive relapsing MS (PRMS).
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