Brain atrophy is something that happens to absolutely everyone, not just if you have MS. In fact, it’s a normal part of ageing. Our brains keep growing until we are in our very late teens and then very slowly start to shrink. This process can also be called brain volume loss, or brain shrinkage. But the damage caused by MS can make this happen a little bit faster.
So why can this happen in MS? Some cells in the brain die as a part of normal aging but in MS there are other processes taking place as well. For example, when myelin is destroyed the axon becomes much more vulnerable to further damage from the immune system. Sometimes resulting in the loss of the whole neuron. The continued loss of neurons and myelin can lead to the brain shrinking faster than normal.
The brain tries to cope with this damage by replacing the myelin and by using other pathways to re-route signals around these broken connections. But as these alternative pathways become damaged and broken themselves due to MS, the brain can no longer compensate.
Because the brain can find ways to compensate for some of this damage, changes to the brain can take place early on in MS, before you start to notice any symptoms.
These early changes in MS, including damage to neurons, brain atrophy and the development of lesions, are important as they have been linked to a number of problems, including long-term disability, problems with walking, vision, sexual function and mental health.