Getting a diagnosis of multiple sclerosis (MS) can take time and often comes with a lot of uncertainty. For some people, it can take years from the time symptoms first appear to when they get a clear diagnosis of MS.

For some people, it can take years from the time symptoms first appear to when they get a clear diagnosis of MS.

For many people, having to wait and see if the disease flares or gets worse after the first episode is one of the more challenging parts of the diagnosis process. A healthcare provider may initially suspect other conditions, or they may even misdiagnose the person. Some people have multiple long-term conditions, which can make it hard for neurologists to tell which one is causing symptoms that look like MS.

How Is MS Diagnosed?

MS can be difficult to diagnose. There isn’t one test that can clearly confirm it. To diagnose MS, doctors look for all three of the following:

• Damage in at least two separate parts of the central nervous system (CNS), which includes the brain, spinal cord, and optic nerves
• Signs that the CNS damage occurred at different points in time
• Other possible conditions have been ruled out

Some people may be diagnosed with clinically isolated syndrome if they’ve had symptoms of MS and a lesion (or area of damage) shows up on a scan in just one part of their CNS. Those who have a lesion but no MS symptoms may be diagnosed with radiologically isolated syndrome. People diagnosed with clinically isolated syndrome but not MS may be regularly checked for new lesions. They may even be treated with disease-modifying therapy — medication that helps slow the progression of MS and reduces future flare-ups.

About 85 percent of those diagnosed with MS are initially diagnosed with relapsing-remitting MS, while the remaining 15 percent are diagnosed with primary progressive MS.

Diagnostic Tests

Some tests can provide proof of damage caused by MS, and others are done to rule out other conditions.

Medical History

Your doctor will take a thorough history, asking about:

• Symptoms over time
• Family medical history
• Birthplace
• Possible exposures to toxins or infections

A doctor may find clues in your medical history that help identify risk factors, support a possible MS diagnosis, or point to another condition instead.

Neurological Examination

The doctor will carefully examine your eyes and reflexes for signs of nerve damage. You’ll be asked to move your arms and legs in specific ways to test for weakness or lack of coordination. The doctor will test for loss of sensation by touching various parts of your body with a vibrating tuning fork or sharp or dull items. The neurological exam gives a clear, medical look at signs and symptoms that could suggest MS or another condition.

Magnetic Resonance Imaging

Magnetic resonance imaging (MRI) is one of the most valuable tools used in studying MS and is a reliable source of criteria to diagnose MS. MRI uses a strong magnetic field and radio waves to measure the relative water content in the tissues of the CNS. Some types of MRI use a contrast dye called gadolinium, which is given through a vein. MRI scans offer the most detailed view of the central nervous system without surgery or other invasive methods.

Getting a brain MRI should be painless, but the machine can be very loud. Wear earplugs to protect against ear damage. Be sure to report any metal content in your body — pacemaker devices, vagal nerve stimulators, orthopedic hardware, shrapnel — to the doctor so they can ensure your safety during the procedure.

MRI scans can show the location, extent, and number of lesions on the brain, spinal cord, and optic nerves. Some types of MRI can differentiate between current inflammation, newer growing lesions, and older sections of permanent damage. MRI can reveal “silent” damage to the CNS that is not causing symptoms.

Most MS diagnoses are based in part on MRI results over time. After a diagnosis of MS is made, most people continue to receive regular scans to track whether (or how quickly) the disease is progressing.

Evoked Potential Test

An evoked potential (EP) test is sometimes part of the diagnosis process for MS. EP measures electrical activity in the brain in response to specific stimuli.

During an EP test, wires are placed on the scalp in certain areas. The doctor or nurse will then provide stimuli such as light, sound, or physical sensations as the test records brain activity, checking for areas where electrical conduction is slower due to demyelination. EP tests are usually painless.

EP tests can help confirm MS by detecting nerve damage that may not cause symptoms and might be missed by other tests.

Cerebrospinal Fluid Analysis

The CNS is surrounded by a liquid called cerebrospinal fluid (CSF). The CSF cushions and protects the brain and spinal cord, circulates nutrients, and removes waste from the CNS. CSF analysis is a useful tool in diagnosing many neurological conditions.

CSF is collected via lumbar puncture, also called a spinal tap. During the procedure, you'll be asked to lie on your side with your knees pulled up to your chest to create space between the vertebrae. The doctor or nurse will clean an area over the spine in your lower back and insert a hollow needle between two vertebrae into the spinal canal, the space where the spinal cord is located. They will draw out a small amount of CSF, then bandage the puncture site.

Some people may experience discomfort during a lumbar puncture, while others develop headaches or backaches afterward. You may need to lie down for a while after the lumbar puncture and avoid strenuous activities for the rest of the day.

In most people with MS, a CSF test will show higher levels of immunoglobulin G (IgG) antibodies and proteins called oligoclonal bands. These findings suggest inflammation in the nervous system but don’t prove that a person has MS.

Ruling Out Other Conditions

Dozens of other conditions can produce MS-like symptoms, and all of these must be ruled out to make an accurate diagnosis of MS. The process of ruling out similar conditions is referred to as differential diagnosis. To list just a few conditions that might be considered:

• Other demyelinating and autoimmune diseases of the brain or spinal cord (conditions that damage the protective coating around nerves or cause the immune system to attack the nervous system)
• Infections such as Lyme disease, syphilis, and HIV
• Other autoimmune disorders, such as lupus or Sjögren’s disease
• Inherited conditions such as mitochondrial disease and leukodystrophies (genetic disorders that affect how cells produce energy or damage the white matter in the brain)
• Nutritional deficiencies
• Brain tumors

Dozens of other conditions can produce MS-like symptoms, and all of these must be ruled out to make an accurate diagnosis of MS.

Your neurologist may be able to rule out many of these conditions quickly based on your medical and family history or simple blood tests. Other disorders may require time and repeated tests before they can be confirmed or ruled out. Having other medical conditions alongside MS can make the diagnosis more complex and may eventually lead to multiple diagnoses.

What Is the Prognosis for MS?

Survival rates for those with MS are improving over time. On average, the lifespan of a person with MS is about seven years shorter than that of other people. Having comorbidities (other health conditions at the same time) like depression, diabetes, or heart disease may increase the risk of death in someone with MS.

There’s no cure for MS, but it can be treated. In recent years, more than 16 treatment options for MS have been approved that can help lower the number and severity of MS flares and slow the disease over time. These options give many people a better chance of maintaining their independence and quality of life. Ongoing research is leading to more effective treatments and new ways to manage the condition.

Find Your Team

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

Have you been diagnosed with MS? What was your experience like? Share in the comments below, or start a conversation by posting on your Activities page.