The 3-Step MS Diagnosis Method
A common complaint I hear is that either getting a diagnosis for MS has taken a really long time or it hasn’t happened yet for people who believe they have this disease, so I was really interested in learning more from Dr. Mark Keegan, Mayo Clinic, on his 3-Step Method to Diagnose Multiple Sclerosis. He gave this talk as part of the 2016 Annual Consortium for MS Centers (CMSC) meeting and was part of a larger conversation about the challenges of diagnosing and misdiagnosing MS. I have already written about the problem of misdiagnosing MS, which was presented here by Dr. Andrew Solomon, who I interviewed for my earlier article.
Dr. Keegan’s talk tackled the issue of diagnosis and he clearly outlined the signs he looks for when diagnosing MS as well as when those signs can be an indication of something other than multiple sclerosis, something he labelled ‘pitfalls.’ He is the author of a recently published medical book Common Pitfalls in Multiple Sclerosis and CNS Demyelinating Diseases. The three steps he uses when working up an MS diagnosis are:
- Classical clinical features of MS
- The neurological exam results
- Investigations (tests used)
Step 1 – Classical Features of MS
Dr. Keegan lists the classic clinical problems of MS include optic neuritis, diplopia, trigeminal neuralgia, sensory myelopathy, neurogenic bladder, gait impairment, fatigue and memory. If you have MS you have some or even possibly all of these problems and understand what they mean in context with our disease. But the pitfalls, the other possible reasons why we may experience this problem were illuminating and may even overlap what we experience because of our own MS. Let me share a few examples so you get a better sense of this-
In classic optic neuritis (ON) for MS, we would have visual loss or change in one eye, pain and it would progress in hours to days and resolve on its own over an extended time. In ON that is most probably not caused by MS, it would be mild or even painless, lasting only a brief time.
In classical clinical presentation of the MS neurogenic bladder, the person would have urgency, incontinence or hesitancy (or maybe all of these) and subject to recurrent UTIs. The non-MS bladder symptoms would only be having the urinary frequency and Dr. Keegan suggests that points to an anatomical problem, such as pregnancies or previous bladder surgeries and not MS.
Fatigue in MS and the associated diagnostic pitfalls were interesting to consider because in the pitfalls he notes fatigue is very common and non-specific and often brought on by increased temperatures or depression. Everyone can experience fatigue at some time from those factors whether they have MS or not, and fatigue in itself is of little help in diagnosing MS.
Step 2: The Neurological Exam
The second step in his 3-step process is the neurological exam, which Dr. Keegan says when done properly the person can easily fall into one of three categories – normal, multiple sclerosis, or other neurological disorders. In the neuro exam with MS symptoms, he lists the examiner may find mild memory problems, optic neuropathy including problems with field, color and acuity. MS problems from the cerebellum might appear as the neuro symptoms dysarthria or gait ataxia. The gait of a person with MS may be spastic or ataxic.
In non-MS but still indicating other neurological disease the doctor might find the person has dementia, and different problems involving the cranial nerve and brainstem. He also lists the motor problems of fasciculation as most usually not MS related.
Step 3 – The Investigational Tests
The 3rd and final step in his diagnosis process is to look at the evidence gathered from the tests of MRI, spinal fluid evaluation and evoked potentials, as well as looking for evidence of any of the many MS mimics. These results are usually straight forward, such as the classic patterns of MS caused brain lesions in the brain and spine don’t look like any other disease process. He shared with his audience several MRI brain and spinal cord images that did and did not display classic MS appearance. In particular he pointed out examples of lesions that are often misnamed as MS by radiologists when in fact they are more likely to be from migraines, smoking, hypertension or aging.
A Missing Step
Dr. Keegan put the audience through the mental exercise of several patient case presentations, challenging us to use the 3 step process to determine if we were indeed looking at someone with MS. Dr. Keegan’s talk made this process sound fairly straight forward but I think there is a fourth step he should officially include in his process- that is where the neurologist stops and listens to the patient and gathers their history. Our experiences leading up to sending us to see the neurologist in the first place can add additional details to the diagnosis trail.
Overall, this was a good presentation on how the MS diagnosis process works, and it was yet another opportunity to reflect on the complexity of this disease and the challenges clinicians face when looking at a new patient and possible MS.
Wishing you well,