| All the main symptoms of multiple sclerosis (MS) | | | | combined with radio waves to map water |
| can potentially be explained away separately, so | | | | molecules. |
| doctors should not diagnose MS unless they are | | | | - When a patient is placed in a strong magnetic |
| convinced about their diagnosis. This means that | | | | field, the nuclei of the hydrogen atoms in water |
| the symptoms need to be assessed in a | | | | line up with the magnetic field. |
| structures way. | | | | - Computers track that process and create virtual |
| This article explains the main tests used for MS. | | | | slices of the inside of your head! This sounds |
| A. Nervous system function tests. | | | | worrying, but is quite painless, and only involves |
| These are usually the first tests the doctor | | | | lying down and being slid into a large tube for a |
| carries out, and are basically an organized test of | | | | few minutes, while machinery clunks around about |
| your reactions and reflexes, usually including: | | | | your head. |
| - tapping a knee with a rubber hammer to check | | | | - If you have MS the computer will produce |
| reflexes. This is a quick and cheap way for a | | | | images showing scars (or "lesions"). These MS |
| doctor to get an idea how fast the nerves are | | | | lesions have been left after the brain has repaired |
| responding, and is a frequent starting point to | | | | damaged nerve tissues. Your doctor should be |
| many examinations of the nervous system. | | | | able to show you MRI images showing the lesions |
| - watching how the patient's eyes follow the | | | | dotted about like islands in the sea of your brain. |
| doctor's forefinger from side to side. | | | | C. Evoked Potential Tests. |
| - asking the patient to walk "toe to heel". | | | | These tests involve electrodes being strapped to |
| - asking the patient to touch the nose (or the | | | | the head and show the time the nerves take to |
| forefinger of one hand against the forefinger of | | | | respond to touch, sight and sound. They are now |
| the other hand) with the eyes shut. | | | | only used as back-up to a diagnosis where a MRI |
| - asking the patient to ripple the fingers on the | | | | Scanner is not available or its use is impossible |
| table as if miming playing the piano. | | | | (maybe where high magnetic fields would be |
| - checking how sensitive the backs of the hands | | | | dangerous to the patient), or the MRI Scan was |
| or soles of the feet are to light touch. | | | | somehow inconclusive. |
| B. The MRI Scan. | | | | D. Spinal Tap (or lumbar puncture). |
| Magnetic Resonance Imaging (MRI) allows the | | | | As a back-up diagnosis, a small amount of fluid |
| hospital to create a computer image of the inside | | | | from the spine might be tested. MRI scans now |
| of the brain of a living person in a way that was | | | | shows lesions in the brains in 95% of cases |
| totally impossible before the 1980s. If you have | | | | where MS is diagnosed, but if the images are not |
| been recently diagnosed you will probably know | | | | conclusive or a high magnetic field could be |
| the MRI scan is now the key tool in the diagnosis | | | | dangerous to the patient than a spinal tap is |
| of MS. | | | | needed. The tests are not dangerous but the loss |
| How does a MRI Scanner work? | | | | of spinal fluid can leave the patient feeling very |
| - MRI scanners use a strong magnetic field | | | | unwell for several hours. |