The McDonald Criteria

[Quixotic1]

THE MCDONALD CRITERIA (revised 2005)
(The Myth of the 9 Lesions)

APPROACH TO THE DIAGNOSIS OF MS


First, you need to understand that MS always was, AND STILL IS, mainly  a clinical diagnosis.   The definition of “Clinical Diagnosis” is:

A diagnosis that can be made on the basis of the history and the physical exam alone.  Yes, that means that in some cases, the diagnosis of MS can be made without using the MRI or other test at all.  However, this is unusual, but it points out clearly the need for a thorough history and physical at the beginning of the diagnostic process.  Many of the clues to the disease will already  be there.  In countries where MRIs are available, they are always obtained.  And, in practice, the results of the MRI often overshadow the "clinical" findings from the patient's history and the neurological exam, especially if the MRI is negative or atypical.  According the guidelines of diagnosis, this MRI would not have to be positive in order for the neurologist to be confident the person has MS.  However, it takes a smart and very confident neurologist, usually an MS Specialist, to diagnose MS with a normal MRI.  It does happen, though.

The categories of MS are also based solely on the patient's experience, that is, their history of symptoms, of resolution, and of accumulation of disability.  The categories are discussed more fully in another Health Page (see "Categories of MS").  These are Relapsing Remitting MS (RRMS), Secondary Progressive MS (SPMS), Primary Progressive MS (PPMS), and Progressive Relapsing MS (PRMS).  About 85% of people with MS will have the Relapsing Remitting form.  For this reason, physicians begin looking a patient with suspected MS from the standpoint of attacks and remissions.  

What is an Attack?

An attack (relapse, flair, exacerbation) of MS is the appearance of new neurological symptoms or the worsening of old neurological symptoms of the kind that are seen in MS.  An attack may be documented from the report of the patient.  In this case it is subjective.  Or it may be observed by the doctor (as in descovering a new problem on the neuro exam), though usually it is a combination of the two.  Anything problem observed by the doctor is said to be "objective."  An attack must last at least 24 hours.  An attack does not include a pseudoattack, which is the temporary worsening of symptoms that can occur elevation of the body's core temperature (as with fever or overheating).  It also does not include single paroxysmal events (sudden jerks, brief loss of vision, single spasms of a muscle, a single bout of dizziness).  If the single event occurs mutliple times over a period of more than 24 hours it would qualify as an attack.  As noted above an attack often does include more than one symptom.

How Often Can Attacks Occur?

The time between attacks must be at least 30 days, during which the symptoms improve, resolve, or are stable in their intensity.  So, a second attack must be at least 30 days from the day the first attack began to improve or stabilized.  This period between attacks is called a remission.  Clinically, a patient with RRMS is always either in an attack or in a remission.


THE IMPORTANCE OF THE HISTORY AND NEUROLOGIC EXAM

So you can see that the whole diagnostic process must begin with a thorough history from the patient of their symptoms, when they started, how they progressed, whether they improved and how much they improved, and whether they ever returned.  It must look for a pattern of waxing and waning of symptoms, noting when new symptoms appeared.  The physician must put together a timeline of the patient's complaints and symptoms looking for a pattern of "Relapse and Remission."   The history should include the things that make symptoms worse or improve them, the pattern of symptoms severity with respect to time of day, level of exercise, temperature, and whether the symptoms became worse after things like infections, pregnancy, severe life stressors, or overexertion.  It should be complete in other respects including non-neurological symptoms and events especially just preceding any attacks.  The patient's Family History should be noted with respect to neurological illnesses, including MS, and for signs of MS Mimics in other members of the family.  It is imperative that the neurologist pay close attention and devote time to hearing what the patient can offer.  No patient should be comfortable with a doctor that does not take this time in one way or another.

The neurological exam is just as important!  It should be a thorough exam, that takes a good amount of time.  It should cover multiples tests in each part of the neurological system.  It is a head to toe exam, and done well, can be exhausting.  It should cover the multitude of tests of the face muscles and eye movements.  There is also a thorough check of the major muscle groups through the body comparing one side to the other for symmetry.  There should be checks for balance and coordination.  There should be some testing of the sensation throughout the body using 2 or more tests of sharp/dull, soft touch, hot/cold, vibration, two-point discrimination and joint point-position sense.  The doctor should observe the patient walking a good distance (more than the 4 steps across the exam room), walking on the toes and on the heels.  Finally, several tendon reflexes should be checked and compared side to side.

During the neurological exam the doctor is looking for "clinical lesions."   A clinical lesion is an abnormality on the exam that is objective evidence that there is damage in the nervous system.   Examples of "clinical lesions" are 1) hyperactive reflexes which signal damage in the spinal cord, 2) problems with the muscles that move the eyes indicating a problem in the brainstem, 3)  spasticity, usually also from the spinal cord,  4) positive Babinksi or Hoffman's test, and 7) paleness of the optic disc at the back of the eye.  These are just a few of many dozens that can occur.

Please note that the word "lesion" is used in two different ways throught discussions of MS.  There are "clinical lesions" as described above.  These are areas of the CNS that must be damaged in order to cause the problems seen in the body.  There are also "MRI lesions" which are the abnormalities "seen" on the MRI images.  The two are not always the same.  One can have a clinical lesion that does not show up on the MRI.  There can also be white spots on the MRI that don't appear to have a symptom associated with them.  For clarification of this point please see the Health Page "Lesions vs. Symptoms."

So, it becomes clear that the neurologist must listen to and exam the patient carefully at some point early in the diagnostic process before making any judgment on the diagnosis.  The first clues about whether this is MS, a mimic or something else will come from this process.  Be wary of the neurologist who skips these steps.

Quix

[Quixotic1]

I really recommend for all people in Limbo - Read this Carefully.  It explains a lot!

Quix

[latte224]

Thanks, Quix.  I can see where I have documented clinical lesions, but I think the neuro has lost sight of that.  He seems to only focus on what he sees in the exam at hand without remembering what showed up (and then resolved) before..

[IUMOM2]

As always, Quix, a great thread. Here's another scenerio for you. What about using other test results to count as an objective sign? For instance, I had an ENG which showed an abnormality in the CNS, not from the ear itself.

I also had neuropsych testing showing problems similar to those found in MS. And, I had urodynamics testing that showed a slow flow rate and retention. The urologist has stopped short of calling it a neurogenic bladder, but he goes on to say he is treating me as if I have a neurogenic bladder. I'm suppose to be taking Flomax (need to get back on that again).

Thanks for all of your help.

[Quixotic1]

Would you post this question on the front page.  We have another person posting who had her lesions discovered by accident.  It's a great thing to discuss.

Quix

[sunshine8]

I wanted to thank you for doing all of this work on the criteria. I really appreciate how you broke it down. I have been doing alot of reading in the last few weeks since my Neuro gave me a "probable MS" diagnosis.

I still have a question..... I didn't present with clinical symptoms, but instead had numerous lesions on my first MRI, and then showed more lesions on my 2nd MRI at the 6 month mark. It was all by accident that this was discovered. My only symptoms so far have been dizziness of and on for the last year and the Nuero noticed a slight left hand tremor on exam. I can't really establish a patterns on the symptoms coming and going yet. My LP, VEP, EEG, and bloodwork have all been normal. My Neuro is reluctant to officially diagnose MS because of the lack of clinical symptoms. If I read the criteria right, you really need the clinical presentation for a diagnosis. Is this correct?  What about those of us that are "atypical" and don't neccessarily have symptoms that have shown as "attacks"?

I feel like with all of the reading I have been doing lately to get up to speed, that I should have just gone to medical school years ago. )

My Neuro's office called today with my schedule.  They have me doing another MRI in 4 weeks, with an appointment with him a few days later.  That will make my 3rd MRI in 8 months. Yippie!

-Amy

[Quixotic1]

nikki -  Thank you so much!

I bumping this up, because it is such important information and I don't want interested people t miss it!

Quix