Opinion: Christina Applegate puts a face on one of the most consequential challenges in neurology

Five years after being diagnosed with multiple sclerosis, actor Christina Applegate revealed this week that she had been misdiagnosed. Her experience puts a public face on one of the most consequential challenges in neurology: how to diagnose a complex disease early enough to prevent irreversible damage without sacrificing accuracy. How MS is diagnosed has changed dramatically during my nearly four decades in the field. When I began my career, physicians often had to wait for symptoms to recur before they could confirm MS. Today, advances in imaging, biomarkers, and diagnostic criteria are helping us recognize the disease earlier, when treatment may have the greatest opportunity to prevent irreversible neurological damage. But progress brings a critical responsibility. Too many people still spend years searching for an accurate diagnosis, while others are told they have MS when another condition is responsible for their symptoms. Applegate’s experience is a powerful reminder that the future of MS diagnosis cannot be about speed alone. Our goal must be both: diagnosing MS earlier and getting the diagnosis right. The challenge is that MS does not look the same in everyone, and other neurological disorders can produce similar symptoms. Signs such as numbness, vision changes, fatigue, and difficulty walking can occur in many other neurological disorders. Even abnormalities detected on an MRI are not necessarily unique to MS. The consequences of both misdiagnosis and delayed diagnosis can be substantial. Someone incorrectly diagnosed with MS may receive treatments they do not need, potentially exposing them to unnecessary risks while delaying appropriate care for the condition actually causing their symptoms. For people whose MS goes undiagnosed, time matters enormously. While there is not yet a cure for MS, there are more than 20 therapies that can help reduce disease activity and slow worsening for many people living with MS. Research has demonstrated the importance of initiating appropriate treatment early in the course of disease, before neurological damage accumulates. Every unnecessary delay can mean a missed opportunity to protect long-term neurological health. Fortunately, decades of research have fundamentally changed what is possible. Today, we have better diagnostic tools, more sophisticated imaging technologies, and a deeper understanding of MS than at any point in history. Yet significant challenges remain in ensuring that these advances reach the people who need them. One of the most significant developments has been the evolution of the McDonald Diagnostic Criteria, the internationally recognized guidelines physicians use to diagnose MS. Working in partnership with the European Committee for Treatment and Research in Multiple Sclerosis, the National Multiple Sclerosis Society helped advance these criteria, contributing to progress that has shortened the diagnostic process from years to months in many cases. The latest revisions incorporate new imaging techniques and biomarkers designed to improve both the speed and accuracy of diagnosis. One particularly promising example is an MRI technique that identifies the central vein sign, a feature that can help physicians distinguish lesions associated with MS from abnormalities caused by other conditions. Alongside progress in spinal fluid biomarker research, this technology offers the potential for earlier, more accurate diagnoses. Artificial intelligence and sophisticated data analytics may eventually help clinicians recognize patterns in imaging and other clinical information, identify people who warrant further evaluation, and improve diagnostic precision. These tools are still evolving, and they will require rigorous research and validation before they can be widely incorporated into clinical practice. But even the most sophisticated diagnostic tools cannot improve outcomes if patients cannot access the specialists and health care systems equipped to use them. Access to neurological care across the country is uneven. Some communities face significant shortages of neurologists, particularly those with specialized expertise in MS. Patients may wait months for appointments, travel long distances to see specialists, or encounter lengthy referral processes before receiving the evaluation they need. Clinician education is equally important. Primary care providers are often the first professionals to evaluate someone experiencing unexplained neurological symptoms. Helping them recognize potential early signs of MS and understand when to refer patients for neurological evaluation can make a meaningful difference. Applegate’s willingness to share her experience has brought attention to an issue that extends far beyond any one person’s diagnosis. We have transformed our ability to recognize and treat MS over the past several decades, but scientific progress alone is not enough. The next challenge is ensuring that these advances translate into earlier answers, more accurate diagnoses, and better outcomes for everyone affected by the disease. That will require continued investment in research to develop and validate better diagnostic tools, better education for the clinicians who first evaluate patients with unexplained neurological symptoms, and improved access to neurologists and MS specialists. Together, these efforts can help smooth the often difficult path from the first unexplained symptoms to an accurate diagnosis, while reducing the risk of both misdiagnosis and unnecessary delays. The goal is not simply to diagnose MS faster. It is to get the diagnosis right, as early as possible, so that no one loses precious time, or the opportunity for appropriate treatment, while searching for answers. Bruce Bebo, Ph.D., is chief research and medical affairs officer at the National Multiple Sclerosis Society. A cellular immunologist, he has dedicated nearly four decades to advancing research into multiple sclerosis, a commitment inspired by his mother’s experience living with the disease.