There is no simple test to diagnose multiple sclerosis and everyone's diagnosis experience is different. Neurologists use a set of guidelines called the McDonald criteria and a combination of medical history, examination, MRI scans and lab results to rule MS in or out.
It can take time to get answers because multiple sclerosis is difficult to diagnose. Symptoms like the ones found in MS are seen in other health conditions, so doctors will want to rule these out first.
It is quite common to remain undiagnosed even after all the tests for MS. If this happens to you, then a period of watching and waiting may be necessary to see how your symptoms develop. It can be very frustrating, but time can help to separate MS from other conditions. Sometimes, it is impossible to be absolutely certain.
There are a number of different tests and other important considerations that neurologists use to help diagnose the condition. While your medical history and neurological examinations can suggest MS, your neurologist will refer you for one or more of these tests to be sure:
Note that although there is no blood test for MS, your doctor may request one to rule out conditions with similar symptoms to multiple sclerosis.
You may have experienced unusual symptoms over many months or years. Perhaps they improved or went away after a while. Or they seemed unimportant at the time. Maybe you found other very reasonable explanations, such as exhaustion from a new baby or stumbling more because you are getting older.
Tell your neurologist about any symptoms that you've had over the years, for example numbness or problems with your eyes. They will want to review your test results alongside your medical history to decide whether it adds up to MS.
When preparing for appointments you may find these links useful:
There are some simple tests that a neurologist may carry out if they suspect MS. These involve checking your movement, coordination, vision, balance and reflexes. They can indicate if and where any damage to central nervous system has taken place. They are usually carried out in an ordinary clinic room and no special preparation is needed.
The most common next step is an magnetic resonance imaging scan (MRI) of your brain. Your neurologist may ask for a spinal cord scan if they feel it is appropriate. An MRI scan can detect the scars caused by MS. These are called lesions and everyone gets more of these white patches in their brain as they get older. Your neurologist will judge if they are age-related or a sign of MS.
Sometimes a dye known as a contrast agent is injected into your vein before the scan. This helps the radiologist and neurologist tell the difference between active MS lesions and older scarring.
For more information, consultant neurologist Will Brown explains MRI scans as part of our 'Ask the expert' series. He covers how they help diagnose MS, what neurologists look for and why you can't interpret your own scan.
To get an idea of what's involved in an actual scan, watch research radiologist Victoria Lupson's explanation in the video below. She addresses common concerns and things you can do ahead of your appointment, as well as demonstrating how it works in practice:
You may be asked to have a lumbar puncture, which involves taking a small amount of cerebrospinal fluid from your spine. The sample is then analysed in the laboratory to see if it contains unusual antibodies, fragmented myelin nerve coating or an unusual amount of white blood cells. If found, it might suggest MS or an alternative diagnosis.
To help allay concerns you may have about the procedure, read our in-depth lumbar puncture information. There you will find a video of Professor Coles outlining what's involved. From his experience, those worried about the procedure generally found it better than expected.
This involves putting small electrodes on your head, arms or legs to measure the speed of messages travelling along your nerves from your eyes, ears or skin on your limbs. If the messages are slower than expected, it may be due to MS.
Find out more about evoked potential tests here. You can also watch Professor Coles explain what happens in the different types of test and how they work.
Optical coherence tomography (OCT) is an imaging technique that’s used to create a detailed image of the back of your eye. It’s a quick, non-invasive scan that’s usually carried out by an ophthalmologist.
An OCT scan can show up signs of damage to the optic nerve at back of your eyes, which can be a sign of MS.
Your neurologist is looking for signs of scarring in your brain or spinal cord.
For an MS diagnosis, there needs to be two or more areas of scarring, which happened at different points in time.
Although MRI scans can sometimes show enough evidence to make a diagnosis, it is still unusual to diagnose MS from just a single episode of symptoms.
The guidance used to make an MS diagnosis is called the McDonald criteria.
It can take time to get a diagnosis and this can be difficult, anxious time. You may find these suggestions help lift your physical and mental health:
