The primary goal of medications for multiple sclerosis is to delay or prevent attacks on the central nervous system. No attacks means no new lesions, which means no new or worsened MS symptoms. It can be tough to tell if your new treatment is doing its job and warding off relapses—or simply doing nothing.
“That’s one of the most common questions people ask us: ‘How do I know this is working in my body?’” says Michelle Fabian, MD, a neurologist at The Mount Sinai Hospital. “We have these measures that we use. It’s called NEDA: No Evidence of Disease Activity.”
Doctors check a few criteria to assess how well a medication is working to treat multiple sclerosis.
Signs of MS relapse. If your MS treatment is working well, you should be experiencing no new symptoms from a relapse, a flare-up that causes an attack on the central nervous system. Learn more about MS relapses here.
MRI results. Your scan should not show any new MS lesions on the body if the treatment is working.
Physical exams. Doctors will check your coordination, eye movement, arm and leg strength, and reflexes. “We look at their examinations and make sure that it looks stable,” says Dr. Fabian, “[and] there are no changes from the last one.”
If those markers check out, you’ve achieved NEDA, and your MS medication is considered to be working successfully.
“Some patients will say, ‘How do we know it’s not just me? How do we know it’s the drug?’” says Dr. Fabian. The truth is, there’s no sure way to tell. “If you’re on the drug, and you’re stable, we say that’s great.”
In addition to checking the drug’s effectiveness, your doc will also make sure you’re not experiencing any unwanted side effects about a month after starting a new MS treatment. At the six-month mark, your doctor may do an MRI to check for visual evidence of any possible lesions.
“We wait six months because most of our treatments take time to work,” says Dr. Fabian. “If that looks good, then we usually check MRIs every year.” Besides annual MRI scans, MS patients typically see their doctor every three to six months for physical exams.
Thanks to newer MS treatment options, relapses are surprisingly infrequent—about every one in eight years or less. That’s good news: Preventing a relapse is the best way to keep MS symptoms from progressing. Here’s what doctors recommend to prevent and treat MS relapses.