A to Z of MS
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A to Z of MS Diagnosis
The diagnosis of multiple sclerosis is a clinical judgement made by a neurologist.
There is no one test that will conclusively show a neurologist that someone has MS and diagnosis usually involves a combination of investigations. Similarly, none of the individual symptoms people can experience are unique to the condition, which means that in order to reach a diagnosis, a range of other possible explanations has to be ruled out. This can mean that it can take some time to reach a definite diagnosis of multiple sclerosis.
How multiple sclerosis is diagnosed
To show that someone has MS, the neurologist is looking for evidence of two or more areas of scarring in different parts of the central nervous system that have occurred at different points in time. Although advances in MRI scanning can sometimes reveal enough evidence to make a diagnosis, it is still unusual to diagnose MS from just a single episode of symptoms.
A number of tests are used to try and find information to support a diagnosis.
Medical or clinical history
As the neurologist needs to establish that symptoms have occurred at different times, a discussion of an individual's previous symptoms and health is important. Sometimes an earlier episode of symptoms, such as numbness or double vision, which might have been treated without thought of MS at the time, can prove significant.
There are a number of simple tests that a neurologist can carry out that can suggest or rule out multiple sclerosis as a cause of symptoms. These include checks on movement, coordination, vision, balance, reflexes and other functions of the senses. Information from these tests not only suggests whether someone might have MS but also gives an indication as to where in the central nervous system damage has occurred and which further tests might be useful.
Blood may be taken for testing. There is as yet no blood test that can determine MS but if there are abnormalities, it is an indication that another condition may be present and might be causing symptoms.
Although the patient history and neurological examinations might suggest the diagnosis of MS, the process usually involves one or more tests to look for evidence of MS within the body.
Magnetic resonance imaging (MRI)
MRI creates images of cross sections of the body. The scars caused by MS show up as white patches, giving a clear picture of the effects of MS on the brain and spinal cord.
A lumbar puncture involves inserting a hollow needle into the base of the spine and drawing off a sample of cerebrospinal fluid (CSF) for analysis. CSF is the fluid that surrounds the brain and spinal cord within the skull and backbone.
An evoked potentials test measures the speed of nerve messages along sensory nerves to the brain. Delays in messages, which are often not apparent to the individual being tested, can indicate that there is damage to the nerve pathway.