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).

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, also called impaired thinking, is a neurological problem that affects more than half of people with MS, according to a 2020 review.

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 2019 review.

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 2016 study. Because of this, doctors often recommend changing medications first before considering a break.

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.

MS is a lifelong condition that impacts people in different ways. There are no targeted drugs for cognitive changes related to MS. But if you have RRMS, your doctor may recommend a disease-modifying treatment that can help reduce your symptoms.

Otherwise, many experts suggest cognitive rehabilitation, which includes behavioral interventions that focus on mental exercises or restorative interventions and compensatory strategies to improve cognition, according to a 2021 study review.

Restorative rehabilitation uses repetitive cognitive exercises to reinforce, strengthen, and recover cognitive skills. Meanwhile, compensatory strategies help people with MS learn ways to compensate for their cognitive difficulties by using tools like reminders and visualization.

Dealing with the long-term effects of MS, including the impact it has on the brain, is trying and can often feel overwhelming. But being in regular contact with your treatment team and having a support system in place can help.

If you have concerns about cognitive dysfunction, changes in moods, or would like information on what you can do to address memory issues, talk with your doctor about the next steps. They can help refer you to any other healthcare professionals or recommend treatments that may provide relief.