Multiple sclerosis (MS) is a disease that is extremely difficult to diagnose. The reasons for this include:
- More than 50 symptoms are linked to MS and each person develops symptoms differently.
- Many of the symptoms mimic problems that occur with other diseases.
- There is no blood test for MS, yet.
- Symptoms usually come and go.
- Many symptoms are vague and hard to quantify, such as fatigue, sexual dysfunction, depression and cognitive difficulties -– these often get attributed to stress by general practitioners and patients may never referred to a neurologist.
Things are improving on this front, because of the increased use of MRIs, which allow neurologists and radiologists to actually take a look at the brain and spinal cord for characteristic MS lesions. However, MS is still a very tricky disease to definitively diagnose, and the process may require patience. It is important to find a neurologist that you feel comfortable with and have confidence in to work on your diagnosis -– after all, if you do have MS, this person will likely be your partner in health for a long time.
Diagnostic Tests and Procedures
- Magnetic Resonance Imaging (MRI) Scan
MRIs use magnetic waves to produce images of the brain and spinal cord. A special contrast material (gadolinium) is usually injected for the scan when MS is suspected, as it reacts to areas of inflammation and will "light up" when a , indicating [link url=http://ms.about.com/od/glossary/g/demyelination.htm]demyelination is occurring.
The MRI does not hurt, but can be a strange experience –- it helps if you know what to expect during this test. There are also some things you can do to make your experience better.
As mentioned, this is considered the best test for diagnosing MS, as abnormal lesions appear on MRIs in over 95% of people with MS. However, 5% of people with MS do not have abnormalities that can be detected on an MRI (producing a false negative), and some age-related damage looks like MS lesions (producing a false positive).
- Medical History
The doctor will ask a number of questions about the symptoms that you are currently experiencing and any that you have experienced in the past. It is a good idea to make a “symptom log” before you see the doctor, listing any sort of symptom that you have had in the past, how long it lasted and other information about it. List all symptoms, even if other doctors told you there was nothing wrong. In addition, take all other medical information along, including which prescription drugs you are on, any medical test results you may have and other doctors’ findings. You will also be asked several questions about medical history of relatives, drug and alcohol use, as well as other health issues that you may have had in the past. All of this information will help a neurologist piece together a picture to help determine if MS is a likely diagnosis.
- Neurologic Exam
The doctor will be testing for the following:
- Functioning of the cranial nerves (these control the senses, as well as how you talk and swallow)
- Coordination
- Strength
- Reflexes
- Sensation
He will do this by having you perform tasks (like touching your nose, then his finger in succession), touching you with various instruments (and having you report a sensation or looking for a response himself) and doing an examination of your eyes. These tests do not hurt. The entire test will probably last about 45 minutes, but may be as long as two hours.
- Evoked Potential Testing
Three main types of evoked potential tests are used in the diagnosis of MS. Each of these tests requires that electrodes are attached to your scalp and connected to an electroencephalograph (EEG) to record brainwaves in response to different stimuli. The different tests are:
- Brainstem Auditory Evoked Potentials (BAEP): A series of clicks are played in each ear through headphones.
- Visual Evoked Potentials (VEP): A series of checkerboard patterns are displayed on a screen.
- Sensory Evoked Potentials (SEP): Mild electrical shocks are administered to an arm or leg.
The doctor is looking for both the size of the response and the speed in which the brain receives the signal. Weaker or slow signals may indicate that demyelination has occurred and that MS is a possibility. However, this test is also not specific to MS and abnormalities could indicate another problem. A series of all three tests could take up to two hours to complete.
