MS - Diagnosing multiple sclerosis

If you have unexplained symptoms that are similar to those of multiple sclerosis (MS), see your GP. If your GP suspects MS, they will ask you for a detailed medical history, including past signs and symptoms as well as the current state of your health.

Your GP can refer you to a neurologist (a specialist in conditions of the central nervous system).

If your GP suspects MS, you should see a neurologist within six weeks.

Read more about waiting times in the NHS.

Diagnostic tests

Diagnosing MS is complicated because no single laboratory test can positively diagnose it.

Several conditions have symptoms similar to those of MS, so your neurologist may rule them out first.

It may also not be possible to confirm a diagnosis if you have had only one ‘attack’ of MS-like symptoms. A diagnosis can usually only be made with confidence once there is evidence of at least two separate attacks.

To confirm MS, your neurologist may carry out a number of tests.

Neurological examination

Your neurologist will look for changes or weakness in your eye movements, leg or hand co-ordination, balance, speech and reflexes. This will show whether your nerve pathways are damaged.

Magnetic resonance imaging (MRI) scan

An MRI scan creates a detailed image of your brain and spinal cord.

MRI scans can show whether there is any damage or scarring of the myelin in your central nervous system. The results of the MRI scan confirm a diagnosis in over nine out of 10 people who have MS.

The procedure is painless and usually takes between 10 and 30 minutes. A standard MRI scanner is like a giant tube or tunnel. You may feel claustrophobic when going into the tunnel and the machine is noisy.

Tell your neurologist if you have any concerns about this experience.

Evoked potentials test

An evoked potentials test involves placing small electrodes on your head. These monitor how your brain waves respond to what you see and hear. It is painless and can show whether it takes your brain longer than normal to receive messages.

Lumbar puncture

A lumbar puncture is also sometimes called a spinal tap. A sample of your cerebrospinal fluid (the fluid that surrounds your brain and spinal cord) is taken using a needle inserted into the area around your spinal cord.

This is done under local anaesthetic, which means that you will be awake, but the area the needle goes into will be numbed. The sample is tested for antibodies, the presence of which means that your immune system has been fighting a disease in your central nervous system.

A lumbar puncture is usually only needed if other tests for MS are inconclusive.

Blood tests

Blood tests are usually performed to rule out other causes of your symptoms, such as vitamin deficiencies. In addition, antibody tests may be required, for example to rule out a very similar condition called neuromyelitis optica (NMO).

Diagnosing the different types of multiple sclerosis

Once a diagnosis of MS has been made, your neurologist may be able to identify which type of MS you have.

However, this often only becomes clear over time as the symptoms of MS are so varied and unpredictable.

A diagnosis of relapsing remitting multiple sclerosis (RRMS) may be made if:

• you have two relapses of your symptoms more than 30 days apart
• you have one relapse and an MRI scan shows new myelin damage or scarring three months later

A diagnosis of secondary progressive multiple sclerosis (SPMS) may be made if:

• you have had relapses of your symptoms in the past
• you have become steadily more disabled for at least six months, with or without relapses

MS never starts out as secondary progressive. However, it is possible for someone to be told they have this type if they have had unexplained symptoms for some time.

A diagnosis of primary progressive multiple sclerosis (PPMS) may be made if you have had no previous relapses of your symptoms, and:

• you have become steadily more disabled for at least one year
• an MRI scan shows damage and scarring to myelin
• a lumbar puncture shows antibodies in the fluid surrounding your brain and spinal cord

In rare cases, some people with primary progressive multiple sclerosis can have relapses. This can make it even harder to clearly identify what type of MS they have.

Brain

The brain controls thought, memory and emotion. It sends messages to the body controlling movement, speech and senses.

Inflammation

Inflammation is the body's response to infection, irritation or injury, which causes redness, swelling, pain and sometimes a feeling of heat in the affected area.

Lesions

A lesion is an abnormal change in an organ or body tissue because of injury or disease.

MRI

MRI stands for magnetic resonance imaging. It is the use of magnets and radio waves to take detailed pictures of inside the body.