Dr Jaume Sastre-Garriga from the MS Center of Catalonia opens the workshop by discussing the McDonald Criteria, which ensure that patients around the world will be diagnosed according to the same standards.
He elucidates the general principles for a diagnosis of MS underlying also the new 2024 revisions of the criteria:
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- MS occurs throughout the world’s populations, in all geographic regions, and race/ethnicities
- MS is an exclusion diagnosis (i.e. there is no better explanation)
- Brain and spinal cord MRI remain the most useful paraclinical test to aid the diagnosis of MS
- An abnormal MRI showing typical lesions is required to make the diagnosis of MS
- Misdiagnosis and underdiagnosis may have deleterious consequences for patients
- MS diagnosis should be reassessed periodically
- Statements applied to CIS may also be applied to relapsing patients without a diagnosis yet
Dr Sastre-Garriga highlights the main proposed revisions, thought to make the criteria more widely applicable, and to increase the sensitivity without compromising on specificity:
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- Radiologically Isolated Syndrome (RIS) is MS in specific situations
- The topographies become 5, with the addition of the optic nerve
- Dissemination in Time (DIT) is no longer needed
- Kappa free light chains have become a tool for diagnosis
- Paraclinical evidence is needed to diagnose MS
- Stricter criteria for confirming diagnosis in individuals over 50 years old, or with headache or vascular disorders
- Addition of central vein signs (CVS) and paramagnetic rim lesions (PRLs) as optional tools for diagnosis in certain situations
- Laboratory tests (MOG-IgG Ab) for confirming diagnosis in children and adolescents
After an initial workup suggestive of MS, there are different possibilities. In case lesions are present in two or more topographies, or the patient has a progression for 12 months or more and 2 or more spinal cord lesions, MS may be diagnosed if one or more of the following exams are also demonstrated:
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- Positive cerebrospinal fluid (CSF)
- Presence of central vein signs (CVS)
- Dissemination in Time
- Lesions are present in 4 or 5 topographies of the central nervous system (CNS)
In case lesions are present in only 1 CNS topography (including patients with progression for one year or more), MS may be diagnosed if one or more of the following are also demonstrated:
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- Positive CSF and CVS
- Positive CSF and PRLs
- DIT and CVS
- DIT and PRLs
If an incidental imaging show findings suggestive of demyelinating disease, neurologists need to be very careful about ruling out other conditions. In this case, at least 2 topographies are needed – with one topography there is no way to reach the diagnosis. And if two topographies are fulfilled then MS may be diagnosed if one or more of the following are also demonstrated:
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- Positive CSF
- presence of CVS
- DIT
Dr Sastre-Garriga shows a clinical case, published in 2023 on Arquivos de Neuropsiquiatria by Disserol and colleagues. A 28-year-old woman, with no previous family history of autoimmune or neurological disease, and smokes 5-6 cigarettes per day and is an occasional alcohol drinker. She presented in 2021 with clinical symptoms of optic neuritis. Ten days after, optical coherence tomography (OCT) showed an increase in the left eye of the Retinal Nerve Fiber Layer (RNFL). Visual Evoked Potential (VEP) showed increased latency in the left eye. Magnetic resonance imaging (MRI) showed a lesion in the posterior part of the optic nerve. In this case, with the previous revisions an MS diagnosis cannot be reached, because there is only one topography. On the contrary, with the new criteria an MS diagnosis would be possible.
Dr Sastre-Garriga discusses the worldwide prevalence of MS, which tends to be lower in lower-middle income or low-income regions. There are some regions, like Nepal, from where Professor Chandra, the other speaker of the webinar, comes from, where the prevalence of MS is very low or unknown. Furthermore, Dr Sastre-Garriga highlights that in some places – like Zambia or Kenya – the diagnosis of MS can come after important delays (3.6-year diagnostic delay in Zambia and 4-year diagnostic delay in Kenya).
To conclude his contribution, Dr Sastre Garriga explains that the 2024 MS diagnostic criteria will introduce the concept of biological diagnosis in MS; align the diagnosis more closely with clinical concepts of MS, streamline the overall diagnostic process; are expected to increase specificity in certain clinical scenarios; and will incorporate several paraclinical tools into the algorithm.
Although access to quality neurology services and para-clinical tools remain very important, these criteria will be user-friendly and feasible to apply even in less resourced healthcare environments.
Professor Avinash Chandra, from the NAMS Bir Hospital in Nepal, presents his case 1: a 21-year-old woman referred at the neurology department because of tingling, numbness, & electric shock-like sensations. She was born in Janakpur and lived in Kathmandu. Her symptoms had started at the age of 19, with gait imbalance, visual problems, and frequent falls. Brain and spinal MRI showed hyperintensities in corona radiata, corpus callosum, brainstem, cerebellum, and several cervical spinal lesions. She was diagnosed with relapsing-remitting MS and treated initially with IV methylprednisolone. Beta-interferon 1a was prescribed, then interrupted due to cost and later resumed.
The Case 2 is a 32-year-old woman with a 2 month gradual onset history of neck and ankle pain, and occasional sharp shooting-like radiating to whole left hand. Periventricular, brainstem, and C4-C7 cord lesions were showed at MRI. Oligoclonal bands were present in the CSF and AQP4 and MOG antibodies were negative. She was also diagnosed with relapsing-remitting MS and treated with IV methylprendisolone for 5 days and then she started on oral azathioprine.
In another discussion, Prof. Chandra explores strategies for navigating the complexities of MS diagnosis in settings with limited economic resources, and underscores the importance of public health education, noting that MS can present with symptoms that are often overlooked.