Making a diagnosis
MS is a big diagnostic challenge, and needs a lot of skill and understanding. It is a multisystem disease within neurology, and the list of similar conditions can be that long and that difficult to some times distinguish between them. Making a diagnosis and telling the patient about it is a responsibility and a big moral issue for the neurologist. MS is a chronic illness with no cure for the time being, and it is a progressive disease. It can rick people’s life in all of its aspects. MS affects social life, professional life, and prospective life. Hence, we need to be very careful before we come to a conclusion, and mention the diagnosis to our patient. This is on one side, on the other side of this equation, we need to make a diagnosis and to start the right treatment at the right time. This is another responsibility for the good neurologist who must think from day one about the right treatment at the right time as this has a serious impact on the patient’s life and future. We doctors need to see it that way, and never to treat MS as a disease. We doctors must see our patient’s with MS as human beings before they are MS sufferers and that obviously requires a holistic approach towards management and care. Many MS sufferers are young at the time of diagnosis and usually they are at the beginning of their careers. Most MS patients are young females, they as well at the beginning of making a family. We have to kind, supportive, understanding, and above all “good listeners”. Let me return back to the diagnosis and I promise to talk more about management later on. Making a definite diagnosis of MS can be difficult, but for the time being the diagnosis of MS is principally based on two dimentions according to McDonald’s Criteria:
- Clinical: For a definite diagnosis, we need to wait to see two clear relapses within two years with at least 3 months between each relapse.
- MRI: According to McDonald’s Criteria, we need to see 9 white matter lesions in T2 waited images of the brain, at least 3 of them to be 1 cm in diameter. If we can’t see that number with that description, then we have to see an evidence of dissemination in time and space. That means to repeat the MRI in 3-6 months, and watch for new lesions in new spots in the white matter, or to see the previous lesions getting bigger in size.
Cerebrospinal fluid (CSF) examination according to McDonald’s Criteria is a supplementary test, may be needed if we clinically feel relaxed with the diagnosis of MS, but the MRI fails to show us the described picture. Many of you know that McDonald’s Criteria have replaced the previous Poser’s Criteria in 2001. Poser’s Criteria were applied in the period from 1985 until 2001. Poser’s Criteria were considering CSF as an important diagnostic tool simply because during Poser’s time, MRI was not available or where available, images were not of a very good resolution. Other investigations such as blood tests were only to exclude other medical problems which mimic MS in many aspects i.e those are considered in the differential diagnosis. Currently there is not a single blood test that is sensitive or specific enough to help in diagnosis MS. Some recent researches are concentrating on a very sophisticated blood tests which might prove helpful in the near future. I will mention those blood tests in the area of advances in MS later on. I will show below nice MRI images of classical MS patients from my own collection, and will return back to McDonald’s Criteria as they gradually became out of date in my view.
All of these images were from one of my patient’s with relapsing and remitting MS, who is now on Natalizomab (Tysabri), and she is doing very well. She is having MS for more than 10 years and she is still fully independent, with EDSS of 3.0 at worst time. CSF examination is only helpful these days when the MRI is not conclusive. It is considered as a supportive tool. CSF does not diagnose MS or exclude it.
The significant diagnostic value of CSF analysis for the time being is based on increased IgG value, and the presence of oligoclonal bands in the CSF, but not the serum (blood).
CSF protein may be slightly raised in less than 50% of cases, and usually in the range of 0.5 – 1 g/l, but not more than that (normal 0.15 – 0.45).
Other CSF changes of significance is the slightly increased lymphocyte count in the range of 05 – 50/mm3
I have also to mention that Visual Evoked Potentials (VEP) test still has a place in helping to diagnose MS when all other investigations are inconclusive, and the clinical picture is highly suggestive of MS.
VEP determines the the status of optic nerve in connection with Optic neuritis.
Obviously, the invention of MRI Tesla-3 has made a revolution in the diagnosis of MS which rendered VEP to remain of the stand by for very rare occasions when it could be used for exceptional cases only these days.
I am not yet talking about MRI Tesla-7 which will be a revolution in the diagnosis and determining function as well.
What about the latest MRI Tesla 9.4?!
Finally, in this area, I would say that CT brain scan has a very little value in diagnosing MS, and better if possible not to use it when MS is the question.