Multiple Sclerosis. Everything you need to know

The rigid paper idyll of 1996 held ground for seventeen years, until the march of technology forced Fred Lublin's committee to audit its own rules. In 2013, scientists finally admitted the old classification system was blind: it evaluated purely outward symptoms while completely ignoring the warfare inside the skull. With the arrival of high-powered MRI scanners, it became obvious that the disease could "remain silent" clinically for years while continuously burning out fresh sectors of the brain. Lublin upgraded the system, ruthlessly liquidating the rare fourth type (PRMS) and hardcoding rigid markers—descriptors of activity and progression. From then on, disease courses stopped being static labels: MS was split into "active" and "not active," based on whether a scanner spotted fresh hotspots. Around the same era, new players entered the board: Clinically Isolated Syndrome (CIS), which flags the very first neurological alarm bell, and Radiologically Isolated Syndrome (RIS), where symptoms are non-existent but the tomograph already catches plaques.

Medicine tried desperately to make its paper rooms more flexible, but it only delayed the inevitable. Fresh data from clinical registries was prepping a total alternative to Lublin’s classification: PIRA, or Progression Independent of Relapse Activity. For a long time, doctors believed that during the relapsing-remitting phase, disability only climbs in tiny steps during physical relapses. However, massive recent studies that over-analyzed data from tens of thousands of patients exposed a terrifying truth. It turned out that even when a person goes years without a single flare-up and their MRI scans remain completely clean, multiple sclerosis quietly and continuously burns out the nervous system from within. Smoldering neurodegeneration, as it turned out, is responsible for 80 to 85% of long-term functional decline. This hidden atrophy doesn't wait around for a doctor to officially switch a patient's label to "secondary-progressive"—it fires up from day one of the disease, transforming the division of MS into separate courses into a bureaucratic formality.

Picture the spinal cord as a highway with a dozen lanes: you’re driving smoothly in your lane, listening to your favorite music, and don't give a damn about the state of the asphalt. When multiple sclerosis assaults your lane, you plow into a pothole and experience your first "relapse"—to feel fine again, you just need a course of pulse therapy and a lane change. The slow expansion of a lesion forces you to switch lanes regularly, but as long as there are enough lanes for everyone on the road, it doesn't bother you, and you register it as a "relapsing-remitting course." From time to time, you hit potholes; doctors log "relapses" and extinguish them with hormones. When potholes take over half the road, cars start swerving aggressively and traffic slows down—I’m sure you’ve found yourself in that bottleneck. The true disaster, however, unfolds when practically no lanes are left. Traffic grinds to an absolute halt, and the doctor utters the terrifying words: "secondary-progressive sclerosis." Then again, if your car features a spectacular suspension or if you happened to drive down a lucky lane, you might never notice the potholes at all—in which case, the sclerosis is classified as "primary-progressive."

The situation with the brain is roughly the same, except instead of a highway, you should visualize a massive drifting track. This track is truly titanic, meaning there is far more room to steer around the potholes—which explains why the brain possesses vastly superior neuroplasticity compared to the spinal cord. This is partly anchored in cell counts: the brain carries 86 billion neurons, while the spinal cord holds only 15 million. It’s also critical that 25% of the brain's axons aren't covered in myelin at all, whereas in the spinal cord, that applies to only 5 to 10%.

Following the 2013 classification rewrite, it took another decade for cutting-edge neurologists to admit that Lublin’s concept of "isolated rooms" wasn't just outdated—it was actively harming patients. The actual tectonic shift toward the "continuum" model occurred in October 2024 at the main European ECTRIMS Congress in Copenhagen, when an international panel of experts officially rolled out a massive overhaul of the McDonald diagnostic criteria. Professor Xavier Montalban and his colleagues dealt a heavy blow to the bureaucratic fragmentation of the disease. The 2024 framework erased the foundational border between relapsing and progressive sclerosis, merging them into a single, indivisible diagnostic box: the continuum.

MS was declared a single, indivisible biological process that flows uniformly through a person's entire life. Clinical medicine finally woke up to a harsh reality: while an RRMS patient injects first-line DMTs and celebrates "clean" scans, the slow fire of PIRA is continuously burning out the free lanes of their highway. This revolution inverted the old philosophy of treatment. The escalation strategy—where heavy weapons like Ocrevus or Cladribine were hoarded for a "rainy day" while waiting for an official transition to the secondary-progressive stage—was exposed as a dangerous misconception. The new paradigm demands attacking the disease with maximum force immediately after the very first alarm bell. The objective is to lock down the hidden neurodegeneration and repave the highway before the cars grind into a permanent, incurable traffic jam.

As a multiple sclerosis patient myself, I sincerely hope that the "continuum" concept takes root and completely replaces the harmful "escalation" strategy. Then again, we have to look reality in the eye—it is highly unlikely that the paradigm will shift dramatically over the next few years. The division of multiple sclerosis into separate courses is so deeply entrenched in the medical world that even those who understand the disease correctly are forced to use the abbreviations RRMS, PPMS, and SPMS. Don't forget that this classification is hardcoded into every official source—textbooks, clinical manuals, and clinical trial protocols. Overturning this approach will require many people to utter the terrifying words: "I have been wrong my entire professional life." Consequently, it will likely take a generational turnover of neurologists. But on a macro level, isn't it deeply ironic that Charcot, who first described sclerosis back in 1868, turned out to be completely right in the end?

On Relapses and Remissions of Multiple Sclerosis

The most dangerous myth in the entire MS treatment grid is the concept of relapses and remissions. Frankly, the situation is identical with other autoimmune conditions: their "remissions" reflect a clinical pause, not a biological one. Psoriasis, rheumatoid arthritis, Crohn's disease, Hashimoto's thyroiditis—none of these diseases have true remissions; they only have the illusion of them. Once an autoimmune error occurs, the immune system fires up like a self-sustaining nuclear reactor. The chain of destruction never hits pause just because a patient happens to feel better. Do lymphocytes ever stop a war before a virus is completely wiped out? In autoimmune diseases, they operate exactly the same way—except the body's own tissues are cast in the role of the virus.

The fact that MS symptoms can appear and vanish was clocked back in the first half of the 20th century, long before autoimmune diseases were even discovered. Ever since, it has been an accepted dogma that the disease strikes in sudden bursts, or "relapses". When symptoms stop progressing, doctors declare that the relapse is over and the disease has hit pause—entering "remission". One reason this belief is so bulletproof is that the healthcare machinery hates gray zones. The slow, gradual decline of sick patients is simply too messy for standardized metrics. Over time, the system settled into an artificial equilibrium. The relapse and remission model lives on in the public consciousness largely because the entire global MS treatment market is engineered around it.

A "relapse" is defined as the appearance of new symptoms or the worsening of old ones, sticking around for at least 24 hours. A "remission" is a window where the patient's condition improves, and symptoms disappear or back off significantly. The most common track of multiple sclerosis is considered to be the relapsing-remitting course (RRMS)—a track where bursts of symptoms alternate with windows of calm. It is a baseline assumption that entering remission simply requires "extinguishing" burning lesions with a course of corticosteroids. This became the core component of the treatment model: if you hit a relapse, you get pulse therapy, then you take your DMTs and live your life—right up until the next relapse. The vast majority of neurologists and patients share a rock-solid conviction: if lesions aren't burning, multiple sclerosis has gone to sleep, and the destruction of nervous tissue has stopped.

This logic is simple, understandable, and incredibly streamlined for the medical bureaucracy. Burning MRI lesions and the number of relapses can be counted on a spreadsheet, and remission windows can be measured in months. Yet, all of this is nothing more than statistical noise that doesn’t match the actual biology of the disease. The destructive processes launched by lymphocytes that forced their way into the brain do not grind to a halt just because lesions stop glowing or symptoms back off. The brain's neuroplasticity plays a cruel trick on patients: the dismantling of myelin rolls on, but if it fails to trigger brand-new symptoms or visibly worsen old ones, the system logs it as a "remission". It is precisely because of how the medical grid defined these terms that patients continue to lose neurological functions during total clinical silence. Patients need to remember that remission means the silence of symptoms, not the stoppage of destruction.

The brutal truth is that without aggressive intervention, multiple sclerosis never enters a biological remission. The disease keeps marching—slowly, smoothly, without any dramatic flare-ups. Can anyone actually notice their right leg losing 0.5% of its strength over the course of a month? Can you feel your left hand becoming 4% less coordinated over a year? Vision in the right eye dropping by a fraction of a point over two years, an uptick in urinary urgency, or coordination slipping slightly over recent months—all of this, unfortunately, flies completely under the radar. The bulk of nervous tissue destruction happens smoothly, completely outside the relapses defined by the system. It is during these exact windows of calm that irreversible damage accumulates in the brain.

Yet, the system prefers to deal with discrete, punchy events. Relapses are easy to count, and remission can be packaged as concrete proof that a therapy is working. When a patient is told that "there are no relapses," "the MRI is stable," and "the disease is in remission," it manufactures a comforting illusion of control. This happens not because it maps reality, but because it can be measured and logged on a chart. We are far too used to trusting numbers and metrics, and this is the root of a massive problem in MS treatment. The smooth, gradual progression of the disease is impossible to track on a standard checklist; it falls completely outside the definitions of relapses and remissions. As a result, neurodegeneration happens invisibly to doctors, leaving fading patients completely alone with their suspicions.

If a patient believes the disease only advances during relapses, they are hemorrhaging priceless time—the neurodegeneration process doesn't hit pause during remissions. If a patient thinks that after a course of hormonal steroids the disease has gone on vacation, they are dead wrong. The autoimmune loops triggered inside the brain tissue keep gnawing away at the myelin insulation. Only when a patient understands that the pathological process is running 24/7 do they gain a chance to act intentionally. The most terrifying thing about multiple sclerosis isn't the relapses—it’s what happens between them.

On "Extinguished Demyelination Lesions" on MRI Results

So, a burning spot on an MRI screen is not always multiple sclerosis. Contrast hotspots simply map zones where an inflammatory process has breached the structural integrity of the blood-brain barrier—cracks form in the vessel walls, and gadolinium leaks out into the brain tissue. Sometimes this is the footprint of budding demyelination, sometimes it isn't: a breached barrier can be triggered by dozens of conditions, including chronic stress and severe depression. It’s critical to realize that if "wrong" lymphocytes are absent from your bloodstream, a leaky barrier will never translate into multiple sclerosis. Lymphocytes don't just need to breach the brain—they have to get inside and mistake myelin for an enemy. In other words, Radiologically Isolated Syndrome (RIS) is far from an absolute death sentence or a guaranteed precursor to MS.

Unfortunately, the exact reverse is also true: "extinguished" demyelination lesions do not mean multiple sclerosis has entered remission. Even after pulse therapy, when a patient experiences a surge of energy and lesions stop accumulating contrast, the disease keeps dismantling brain tissue. The lymphocytes that dug into the brain linings view myelin as their ultimate target, and they see it everywhere. Since the enemy is all around them, they fight: they don't just riot themselves; they coordinate the local immune response, and macrophages systematically devour the myelin sheath layer by layer. Lymphocytes have zero reason to leave the brain—they have already found exactly what fits their receptor.

This is where the most dangerous misconception regarding MS hides. When an MRI fails to show active lesions and symptoms back off thanks to the brain's neuroplasticity, patients sincerely believe that "the disease is in remission" and "the drug is holding". The majority are convinced that the destruction of brain tissue only occurs during active relapses—assuming that immunity attacks the nerves in bursts, cutting off signals. Yet, very few stop to think about the actual biology of this process. A "relapse" is viewed as an explosion of the disease, and "remission" as a total ceasefire. If a patient is using a DMT during a window of calm, they credit the medicine for the remission, and when a relapse strikes, they declare that "the DMT stopped holding". The baseline condition that "the drug was holding" and that it deserves the credit for the calm is a dogma that is never up for debate.

Well, the truth is far less comforting: if after a few years of taking a drug you experience a relapse, it actually means the drug failed to protect you from it, even if it was working. The relapse occurred because immune cells had been quietly devouring your myelin over a long stretch of time. The nervous tissue kept degrading, but as long as the brain managed to compensate for the damage through neuroplasticity, you felt zero symptoms. At some point, the "neurological reserve" topped out, and the symptoms broke through—sometimes smoothly and invisibly, sometimes in a sharp flash. The main thing you need to grasp is that the destruction of nervous tissue doesn't just happen during relapses; it happens continuously. A relapse is the breakthrough of symptoms, not the awakening of the disease. On the contrary, sclerosis was working overtime the entire time leading up to that relapse.

The core of the issue is that everyone has been trained to measure MS activity entirely by the number of burning lesions. If there are no contrast spots, the disease is logged as being in remission—even if the patient's symptoms continue to intensify. In reality, a demyelination lesion doesn't accumulate contrast forever. Over time, the autoimmune process dug deep into the brain tissue and stopped disrupting the blood-brain barrier. The healing of the vascular wall doesn't mean demyelination has ground to a halt. For example, shortly after pulse therapy, lesions stop burning—yet this doesn't mean the autoimmune process has been snuffed out. The wall is patched up, but the troublemakers who managed to slip through the gate keep rioting, exactly like the anime Attack on Titan. The assumption that the disease enters remission simply because lesions stop accumulating contrast is the most dangerous trap in the entire MS treatment grid.

On the EDSS Scale and the Room for Statistical Miracles

The first scale engineered to measure the status of multiple sclerosis patients was rolled out back in 1955—back then, it was tagged as the DSS, Disability Status Scale. Its creator, John Kurtzke, was an American neurologist working at a US Veterans Affairs hospital. By an ironic twist of fate, we owe the creation of the primary tool for measuring MS progression to a medical error born out of a total accident. Multiple sclerosis is surrounded by misconceptions on all sides, and measuring the degree of disability is no exception.

In the early 1950s, Kurtzke and his colleague Louis Berlin were testing the efficacy of an anti-tuberculosis drug called isoniazid for treating MS. Isoniazid is a highly specialized antibiotic: its sole mission is hunting down the mycobacteria responsible for tuberculosis. How did such a wild idea even enter anyone's mind? It all came down to pure chance: a World War II veteran with multiple sclerosis was admitted to the hospital for tuberculosis, and after being put on isoniazid, his slurred speech suddenly cleared up and his tremors backed off. In Kurtzke’s defense, autoimmune diseases hadn't been mapped out yet; the medical world was hunting for a hidden virus or bacteria driving MS.

Spotting the anomaly, Kurtzke and Berlin ran a pilot test. The results looked promising, and the VA decided to launch a massive trial across 11 hospitals nationwide. To ensure that dozens of doctors in different wards measured shifts in patient conditions by a unified metric, Kurtzke engineered the 11-point DSS scale. Isoniazid flunked the audit: its temporary positive effect on MS turned out to be the byproduct of the natural fluctuation of the disease. The DSS, however, didn't just survive; it flourished. In 1983, Kurtzke updated the metric with 0.5-point increments, transforming the tool into the Extended Disability Status Scale (EDSS). This expansion turned the scale into an ideal instrument for statistical illusions: the EDSS score became a key clinical endpoint in every single DMT trial.

Here is a curious detail: during the trials for the very first interferon, the EDSS score wasn't even the primary endpoint; they only tracked the number of relapses. When the investigators finally pulled up the data charts for the EDSS scale, they got hit with a freezing shower: the disability progression curves for the placebo group and the Betaseron group practically merged. Mathematically, there was zero significant difference in how their EDSS scores shifted. Despite this, the interferon beta-1b rammed through regulatory approval anyway. However, subsequent DMTs were forced to use disability progression as an endpoint, and the flexibility of interpreting EDSS scores turned out to be incredibly convenient.

The structural vulnerability of the EDSS is that the calculator has been stripped down to a single, flattened final score. Instead of evaluating the patient's status across several distinct functional tracks (cerebellar, visual, bowel/bladder, cognitive, and so on), everything was boiled down to a flat text description of the output. Up to 1.5 points maps to minimal impairment; 2.0 to 3.5 logs moderate issues; and starting right at 4.0, everything hinges strictly on walking distance. After 6.0, the patient requires an assistive device to move; after 7.0, they are restricted to a wheelchair; and past 8.0, they are bedridden and lose significant use of their hands. Look closely at this imbalance: from 0 to 3.5, the patient is more or less functional, but the transition from 4.0 to 7.5 is a slippery slide from minor limitations to total helplessness. The non-linear structure of the EDSS is a prime variable for cooking efficacy numbers: hand-picking the right patients for a trial allows researchers to heavily manipulate the final data.

Some medical registries don't even bother separating scores below 3.5—these impairments are dumped into a single basket and labeled as "mild or moderate". This framework grants investigators massive creative freedom when logging disability shifts, which can artificially inflate the proven efficacy of drugs during trials with compromised blinding. If researchers can guess who is getting the drug and who is stuck on a placebo, the fuzzy line between "mild" and "moderate" impairments can manufacture a wall of statistical noise spanning up to two full points. However, past the 4.0 mark, things aren't any cleaner: the scale shifts its focus exclusively to walking distance, completely blinding itself to other issues. If at a 4.0 mark a patient can trudge 500 meters without resting, the scale doesn't give a damn about how well their hands, eyes, cognition, or bladder are functioning.

When a score is anchored entirely to walking, any decline that doesn't involve the legs can be legally ignored. Vision dropped? "Doesn't move the EDSS". Memory loss, speech glitches, or executive decline? "EDSS remains stable". A tremor takes over the hand, making it impossible to hold a fork? "The scale failed to register a shift". Crushing fatigue, an inability to get out of bed, anxiety, apathy, or depression? "Disability metric is completely stable". This obsessive fixation on walking is the primary flaw of the EDSS. When a pharmaceutical giant boasts that "patients maintained a stable score throughout the therapy," in reality, it frequently means nothing more than the fact that they could still walk. What is happening to the brain tissue remains a mystery; fine motor skills are ignored; bowel/bladder issues and cognitive decline are written off. A patient can lose the ability to tie their shoes due to tremors, but as long as their legs clock the mandatory distance, clinical reports will cheerfully log "moderate" impairment.

Yet, the EDSS manufactures a convincing illusion of rigorous science for patients. EDSS 1.5? Great, nothing to worry about, the impairment is mild—it doesn't matter that the patient can no longer read books and has spent the last year working at half capacity. EDSS 2.5? Zero disability progression, it doesn't matter that the patient breaks down crying every evening because they can no longer track their own thoughts. EDSS 3.5? Still no reason to panic, the impairment is moderate—it doesn't matter that the patient has to run to the bathroom every thirty minutes. A hard number for the degree of disability exists—and on that number, you can build a clean chart, a scientific publication, and an aggressive marketing strategy without asking a single uncomfortable question about the patient's actual status. The main thing is to build an illusion of control and keep the patient from realizing that the number doesn't map reality.

In the end, a scale that was engineered to measure neurological deficits turned into a convenient facade used to mask degradation. The EDSS is completely defenseless against statistical juggling. If you need to prove a drug works, you screen for mild patients, deploy the baseline therapy, and watch their legs. If the data fails, you can always claim that "the EDSS missed the improvement because the scale lacks sensitivity". It’s a universal tool—perfect for pushing drugs and equally perfect for dodging uncomfortable data. Patients are hemorrhaging physical power and bodily functions, but on the EDSS chart, "no disability progression is observed".

Are there alternatives to the EDSS? Yes, plenty of them: MSFC (Multiple Sclerosis Functional Composite), PROMs (Patient-Reported Outcome Measures), Floodlight, and others. Among the old guard, almost simultaneously with the expansion of Kurtzke's scale, the Scripps Research Institute engineered its own tracking matrix—the Scripps Neurologic Rating Scale (SNRS). The SNRS measures far more than the ability to walk: it audits muscle strength, coordination, balance, gait, sensory mapping, speech, vision, reflexes, cerebellar functions, eye movement tracking, general neurological integration, and bowel/bladder functions. This instrument is also far from flawless, but in terms of sensitivity and completeness, it sits incomparably closer to the actual clinical profile. In plain terms, the phrase "no disability progression by the SNRS scale" would carry far more weight than an identical claim regarding the EDSS.