Medically reviewed by Nancy Hammond, M.D. — Written by Sara Lindberg on February 21, 2022
Multiple sclerosis (MS) is an unpredictable and long lasting disease of the central nervous system that disrupts communication between the brain and other parts of the body.
How MS originates isn’t entirely known, but many experts believe the body launches an attack on the nerve-insulating myelin. This causes a delay or disruption of messages from the brain and spinal cord to other parts of the body, according to the National Institute of Neurological Disorders and Stroke (NINDS)Trusted Source.
The damage that happens to myelin, a protective coating in the brain, results in various symptoms. These symptoms can include memory problems, fatigue, lack of concentration, decrease in processing speed, and mood changes.
Here’s an in-depth look at how MS affects the brain.
Cognitive dysfunction in MS
Cognitive dysfunction, also called impaired thinking, is a neurological problem that affects more than half of people with MS, according to a 2020 review. Trusted Source
According to the National Multiple Sclerosis (MS) Society, cognition refers to high-level functions carried out by the brain, including:
memory
planning
problem-solving
processing information
verbal fluency or finding words
visual perception
attention
In general, most people who experience cognitive dysfunction will have mild to moderate problems that may only involve one or two areas. Memory issues such as acquiring, retaining, and retrieving new information are the most frequently reported cognitive challenges.
Another type of cognitive dysfunction many people with MS experience is attention and concentration, specifically divided attention or multitasking.
The National MS Society stresses the importance of early recognition with cognitive changes but also recognizes how subtle these changes may be, especially at first.
Some common early signs may include having difficulty:
finding the right words
remembering what to do in your job or during daily routines
keeping up with tasks or conversations
making decisions
Brain atrophy is a natural part of the aging process. As we get older, brain volume tends to decrease slightly, with most people losing about 0.1 to 0.5 percent each year, according to a 2016 review article.
But for people with MS, especially untreated MS, brain atrophy happens faster than usual and progresses throughout the disease course. The average loss per year is around 0.5 to 1.35 percent.
Brain volume loss in people with MS is due to demyelination and the destruction of nerve cells. It can affect all of the brain or only a limited area or region. When atrophy happens in one location, the decrease of function is limited to that part of the brain.
Brain atrophy often occurs with the first episode of neurological symptoms early in the disease course. It’s also the best predictor of future physical and cognitive disability, according to a
The goal, especially with disease-modifying drugs, is to try and prevent damage to the brain and spinal cord that can accelerate atrophy or loss of brain volume.
Switching medications is something a lot of people with MS consider throughout the course of the disease. You may even think about stopping medications altogether.
It’s important to be aware that stopping disease-modifying medications without replacing them with a new one can lead to an increase in MS symptoms, including cognitive problems.
Also, compared with people who stay on their MS medications, you may have a higher hazard for disability progression, especially if you’re older, according to a
If you have relapsing-remitting multiple sclerosis (RRMS), you’ll likely notice symptoms worsening over time or the development of new symptoms. When this happens, your doctor may talk with you about changing medications.
While a new treatment has the potential to work better, the transition takes time, and you may notice some adverse short-term effects before the medication kicks in. That’s why switching medications requires careful monitoring by you and your treatment team.