multiple sclerosis diagnosis multiple sclerosis diagnosis current standards for diagnosing multiple sclerosis (ms) are based on the 2018 revision of mcdonald criteria. they rely on mri detection (or clinical demonstration) of demyelinating lesions in the cns, which are distributed in space (dis) and in time (dit). it is also a requirement that any possible known disease that produces demyelinating lesions is ruled out before applying mcdonald's criteria. diagnosis of multiple sclerosisanimation showing dissemination of brain lesions in time and space as demonstrated by monthly mri studies along a yearpurposediagnosis via lab test, imaging and symptoms this last requirement makes ms an ill-defined entity, whose borders change every time that a new disease is set apart. some cases previously considered ms are now considered distinct conditions, like neuromyelitis optica or antimog associated encephalomyelitis. because of the requirement of distributed lesions, a single lesion (ris) is not considered ms. for the same reason, the prodromal stage of ms (the unknown condition that causes the lesions) would not be considered as ms if it could be found. sometimes the diagnosis must be retrospective, relying on gradual worsening of neurological signs/symptoms, due to the lack of understanding of the pathogenicity driving disease progression. however, the only definite diagnosis of ms is post-mortem autopsy, where lesions typical of ms can be detected through histopathological techniques. overview multiple sclerosis is typically diagnosed based on the presenting signs and symptoms, in combination with supporting medical imaging and laboratory testing. it can be difficult to confirm, especially early on, since the signs and symptoms may be similar to those of other medical problems. the mcdonald criteria, which focus on clinical, laboratory, and radiologic evidence of lesions at different times and in different areas, is the most commonly used method of diagnosis with the schumacher and poser criteria being of mostly historical significance. while the above criteria allow for a non-invasive diagnosis, some state that the only definitive proof is an autopsy or biopsy where lesions typical of ms are detected. clinical data alone may be sufficient for a diagnosis of ms if an individual has had separate episodes of neurologic symptoms characteristic of the disease. in those who seek medical attention after only one attack, other testing is needed for the diagnosis. the most commonly used diagnostic tools are neuroimaging, analysis of cerebrospinal fluid and evoked potentials. magnetic resonance imaging of the brain and spine may show areas of demyelination (lesions or plaques). gadolinium can be administered intravenously as a contrast agent to highlight active plaques and, by elimination, demonstrate the existence of historical lesions not associated with symptoms at the moment of the evaluation. testing of cerebrospinal fluid obtained from a lumbar puncture can provide evidence of chronic inflammation in the central nervous system. the cerebrospinal fluid is tested for oligoclonal bands of igg on electrophoresis, which are inflammation markers found in 75–85% of people with ms. the nervous system in ms may respond less actively to stimulation of the optic nerve and sensory nerves due to demyelination of such pathways. these brain responses can be examined using visual- and sensory-evoked potentials. trends towards earlier diagnosis prodomal or early phase studies have found increased interactions with health services by people who were diagnosed with ms several years later. the range of symptoms included pain and fatigue. studies continue on whether ms has a prodromal or early phase, and could possibly be diagnosed and treated much earlier. dmt effectiveness a range of disease-modifying treatments (dmt) are now available, to reduce the long-term progression of ms. studies are increasingly indicating that early and aggressive use of dmts is beneficial for long-term outcomes. diagnostic criteria mcdonald criteria main article: mcdonald criteria as of 2021, the mcdonald criteria for ms are the most commonly used. the 2017 mcdonald criteria can be summarize in this table: clinical presentation additional data needed * 2 or more attacks (relapses) * 2 or more objective clinical lesions none; clinical evidence will suffice (additional evidence desirable but must be consistent with ms) * 2 or more attacks * 1 objective clinical lesion (as well as clear-cut historical evidence of a previous attack involving a lesion in a distinct anatomical location) none. * 2 or more attacks * 1 objective clinical lesion dissemination in space, demonstrated by an additional clinical attack implication a different cns site or by mri. * 1 attack * 2 or more objective clinical lesions dissemination in time, demonstrated by an additional clinical attack or by mri or demonstration of csf-specific oligoclonal bands * 1 attack * 1 objective clinical lesion (monosymptomatic presentation) dissemination in space demonstrated by an additional clinical attack implicating a different cns site or by mri.anddissemination in time demonstrated by an additional clinical attack or by mri, or demonstration of csf-specific oligoclonal bands insidious neurological progression suggestive of ms (primary progressive ms) one year of disease progression (retrospectively or prospectively determined) and two of the following: one or more t2-hyperintense lesions characteristic of multiple sclerosis in one or more of the following brain regions: periventricular, cortical or juxtacortical, or infratentorial two or more t2-hyperintense lesions in the spinal cord presence of csf-specific oligoclonal bands okuda criteria these criteria, used mainly for research in ms, define what should be considered a radiologically isolated syndrome (ris). some reports point to the possibility of predicting ris to cis conversion based on oligoclonal bands and neurofilament light chain. research into diagnostic techniques multiple sclerosis diagnosis can only be made when there is proof of lesions disseminated in time and in space. therefore, when damage in the cns is big enough to be seen. it would be desirable to make it faster. the ideal diagnosis schema would be able to determine for any given subject, if he will develop ms, at any point in his life, and when. nevertheless, not enough is currently known about the ms underlying conditions to achieve that. in order to get as close as possible to the ideal diagnosis status, a lot of research into multiple sclerosis biomarkers is taking place currently. biomarkers in ms