There are some tests that can be taken to find out if you have MS.
MRI - An MRI is Magnetic Resonance Imaging. It is a test that produces a picture of your brain. It allows the doctor to see if there are any "plaques" or other abnormalties. The person just lies down on a table that moves inside the machine which is tube shaped, and a magnet sends the information to a computer which in turn makes the images.
CSF - The cerebrospinal fluid surrounds the brain and spinal cord and some parts within the nervous system. A needle can be inserted into the lower back to remove some of this fluid. The fluid is then examined.
There are a few other tests that the doctor may decide to take. It is your doctors decision as to what tests he/she needs the person to undergo so he/she can make a diagnosis.