If you have unexplained symptoms that are similar to those of Multiple Sclerosis (MS), see your doctor. If MS is suspected, your doctor will ask you for a detailed medical history including your past record of signs and symptoms as well as the current status of your health.

Your doctor can then refer you to a neurologist (a specialist in conditions of the central nervous system). Diagnosing MS is complex because there is no single laboratory test that can positively diagnose it. Several other conditions have symptoms that are similar to MS, so your neurologist may have to rule them out first.

Diagnostic tests

In order to confirm a diagnosis of MS, your neurologist may carry out a number of tests that are listed below.

Neurological examination

Your neurologist will look for changes or weakness in your eye movements, leg or hand coordination, balance, speech, and reflexes. This will show whether or not any of your nerve pathways are damaged.

Magnetic resonance imaging (MRI) scan

If you have a magnetic resonance imaging (MRI) scan, you lie down inside a machine called an MRI scanner, while a strong magnetic field creates a detailed image of your brain and spinal cord. The procedure is painless and usually takes between 10-30 minutes.

MRI scans can show whether there is any damage or scarring of the myelin in your central nervous system. Over 90% of people with MS are diagnosed using an MRI scan.

Evoked potentials

An evoked potentials test involves small electrodes being placed on your head, which monitor your brain waves in response 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 lumber puncture is also sometimes called a spinal tap. A sample of your cerebrospinal fluid (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 anesthetic, which means that you will be awake, but the area the needle goes into will be numb.

The sample is then 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, or for a diagnosis of primary progressive MS.

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, often this may only become clear over time, as the symptoms of MS are so varied and unpredictable. This is true of benign MS (BMS), which can only be diagnosed once you have been symptom free for 10-15 years.

There are a different set of diagnostic criteria for the other three types of MS, which are outlined below.

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

• you have two relapses of your symptoms, more than 30 days apart, or
• 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, or
• you have become steadily more disabled for at least six months, with or without relapses.

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

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

Uncertain diagnosis

In some cases, your neurologist may not be able to say for certain whether or not you have MS. This can happen when the test results are unclear; for example, if your symptoms and lumbar puncture results point towards MS, but there is no sign of myelin damage on the MRI scan.

If this is the case, your neurologist may tell you that you have possible MS. You may have to wait for your symptoms to relapse again before a definite diagnosis can be made.

After diagnosis

Being diagnosed with MS can be extremely difficult to deal with. If you, or a loved one has been diagnosed with MS, your neurologist or doctor can refer you for counseling with a support worker with knowledge of the condition. You should also be given the chance to take part in an educational support course about MS.