Neuroplasticity is the ability of the brain to adjust to internal and external environmental changes that physiologically take place during the entire life. Particularly interesting is the response of the brain to damage in patients with multiple sclerosis, which is a chronic disease that leads to inflammatory and neurodegenerative central nervous system damage. While in healthy individuals brain plasticity is based on brain development, learning processes and memory, in multiple sclerosis it involves changes at the molecular, synaptic and cellular level as well as reorganisation of the cortex and brain fibres, leading to the restoration of functions which were lost in the course of acute or chronic damaging processes. Functional magnetic resonance imaging helps examine functional changes associated with the disease and its evolution. Several studies have shown that abnormal brain activation during certain tasks is seen in early stages of the disease. Enhanced functional activation of the brain has been interpreted as adaptation neuroplasticity to counteract the accumulation of tissue damage. The article presents the principles of functional magnetic resonance imaging which plays a significant role in demonstrating neural plasticity. Moreover, the authors discuss molecular factors that are probably responsible for neuroplasticity.