• Doctors measure the effectiveness of disease-modifying therapies (DMTs) in multiple sclerosis (MS) by looking at imaging scans, lab test results, disability assessments, and relapse rates.
• People with MS can ensure their DMT’s effectiveness is assessed accurately by sticking with their treatment plan and reporting all symptoms and side effects to their doctors.

Although DMTs are proven to slow disease processes in MS, they do not necessarily address the MS symptoms you might be feeling. This can be frustrating for those living with MS. You may have wondered whether your DMT is working and whether it’s time to switch treatments.

It can be helpful to learn how neurologists track the effectiveness of MS medications. There are also steps you can take to make sure your doctor has the most complete information about whether your treatment is working.

How Do Doctors Track Treatment Effectiveness?

There are three main ways doctors monitor how well an MS treatment is working. Their recommendations on whether to continue or switch medications are mainly based on:

1. Scan results and lab tests that measure disease progression
2. The frequency of MS relapses (also called disease flares or MS episodes)
3. Whether and how disability progresses

Imaging Scans and Lab Tests

MS is a progressive disease involving lesions in the central nervous system (the brain and spinal cord). Lesions are areas of damage where nerve cells lose their natural insulation, known as myelin, in a process called demyelination. When these lesions form or grow, they are often accompanied by flares of symptoms ranging from muscle weakness and numbness to cognitive difficulties and spasticity. Lesions can be seen on MRI scans, using an injected contrast dye called gadolinium.

An MRI scan of the brain is often used to help diagnose MS for the first time. Initial scans provide a baseline measure of disease burden — how your MS looked at diagnosis, before beginning a DMT. During follow-up appointments, MRI scans may be repeated to assess how your MS is progressing and how well your current treatments appear to be working.

Watch MS specialist Dr. Aaron Boster discuss whether you could be taking too many medications.

Relapses

For people with relapsing-remitting MS (RRMS), the frequency of relapses on their current treatment — compared to before they started DMT treatment — is another key sign of the medication’s effectiveness. Neurologists look at your rate of relapse when determining whether or not your current treatment plan is working.

How well you recover from relapses and flares is another sign of the effectiveness of MS treatment. While many people with MS will eventually transition from having RRMS to secondary progressive MS, the goal is always complete recovery from a relapse without any major symptoms that linger afterward.

Disability Progression

The last of the three main measures of disease activity doctors use are scales that track disability due to MS. Disability scales work in conjunction with regular physical exams, which often involve other tests, like a 25-foot walk test. Disability scales are standardized, meaning that the scales and scoring criteria are the same for everyone with MS — regardless of individual characteristics or demographics. One of the most common scales used today is the Expanded Disability Status Scale, or EDSS.

The EDSS scores disability from 0 to 10. A score of 0 means no disability due to MS, while a score of 10 indicates death due to MS. The scale goes in increments of half a point (0.5) based on MS-related symptoms, including:

• Weakness
• Numbness
• Vision problems
• Speech problems
• Urinary or bowel dysfunction

This scale was first developed for use in clinical trials testing new MS drugs. However, EDSS scores, as well as scores from similar scales, are now widely used by neurologists to monitor treatment effects. EDSS scores can indicate whether your MS disease course is slowing or worsening as you use a DMT.

However, these scales are not perfect. The EDSS, for example, does not do well in measuring cognitive abilities (thinking and memory) or quality of life in people living with MS.

Do Your Part To Help Measure Effectiveness

While doctors base their assessment of your DMT on the measures above, an accurate assessment requires your participation too.

Stick With Your Treatment Plan

It’s important to keep up with your treatment to ensure maximum effectiveness. If treatments are skipped, delayed, or reduced in dosage, the medication may not work as well — or at all. Keeping up with your medication schedule will give you the best shot at limiting the damage MS can do to your brain and spinal cord and lowering the number of MS flares you might have.

If you can’t tolerate taking every dose of your DMT as directed, let your doctor know. This will help them assess how effective your DMT is and whether it’s the right medication for you.

Report All Symptoms or Side Effects

A detailed and accurate medical history is key to tracking disease progression. Your doctor requires your honest input to fully understand how MS affects your daily life. Similarly, be clear with your neurologist and other health care providers about any side effects you experience. They can help you find ways to manage your particular MS symptoms or side effects. If side effects are serious, they may prompt your doctor to consider switching you to a different medication.

Learn more about switching MS treatments, including when and why it might be time to switch.

It can be hard to stick with your treatment if you’re not confident that it’s the best one for you. Choosing a DMT is a collaboration between you and your doctor, a process called shared decision-making.

Before talking to your doctor about switching treatments, take the quiz: What Are Your MS Treatment Goals?

Talk With Others Who Understand

MyMSTeam is the social network for people with multiple sclerosis and their loved ones. On MyMSTeam, more than 187,000 members come together to ask questions, give advice, and share their stories with others who understand life with MS.

Do you have concerns about whether your MS treatment is effective? Share your questions and experiences in the comments below, or start a conversation by posting in Activities.