Summary: Increased visits to hospitals and physicians during the years before a multiple sclerosis (MS) diagnosis—often triggered by early MS symptoms—are frequently signs of active, ongoing disease rather than a separate prodromal phase. These encounters more often reflect unrecognized relapses and neurological events that precede formal diagnosis.
Source: TUM
Multiple sclerosis is an autoimmune disorder that causes damage to the central nervous system and can produce a wide range of neurological symptoms. In early stages, patients commonly experience sensory problems such as numbness, tingling or visual disturbances, but symptoms can vary considerably from person to person.
MS typically presents with repeated episodes of neurological dysfunction—referred to as relapses or demyelinating events—followed by periods of partial or full recovery. Because early signs are often subtle and diverse, even experienced clinicians may find it challenging to interpret them and reach an accurate diagnosis promptly.
Higher-than-average number of medical visits before diagnosis
Previous research has shown that people who are later diagnosed with MS tend to seek medical care and be admitted to hospitals more frequently in the years leading up to the first documented diagnosis compared with people who do not develop MS. This pattern has been interpreted by some researchers as evidence of a prodromal phase—a period of non-specific symptoms that precedes classic disease onset.
Evidence that disease is active well before diagnosis
A new study led by neurologist Prof. Bernhard Hemmer at the Technical University of Munich (TUM) takes a different view. The research team found that many of the medical visits and hospital stays recorded before the first MS diagnosis related to complaints that are consistent with typical MS symptoms. “We believe many of these earlier complaints represent unrecognized MS relapses,” says Prof. Hemmer. “In other words, the disease is already active and causing neurological problems, but it often remains undiagnosed for years.”
The investigators argue that these encounters should not necessarily be labeled as a non-specific prodromal phase, but rather as manifestations of ongoing autoimmune activity affecting the nervous system—events that, if identified correctly, could lead to earlier diagnosis and earlier initiation of MS-specific treatment.
Opportunity to diagnose and treat MS earlier
Earlier recognition of MS relapses could change how clinicians respond to patients presenting with compatible neurological signs. “If we pay closer attention to which early symptoms tend to be overlooked, we may be able to diagnose MS sooner and begin disease-modifying therapies earlier,” says Dr. Christiane Gasperi, first author and clinician-researcher at the Neuro-Head Center at the TUM Klinikum rechts der Isar. Earlier treatment is generally associated with better long-term outcomes in MS, making timely detection an important clinical goal.
Fewer recorded respiratory infections among future MS patients
Interestingly, the study also found that people who later developed MS were less likely to have medical visits for upper respiratory tract infections in the five years before diagnosis. “This was unexpected because MS relapses are sometimes linked to infections,” says co-first author Dr. Alexander Hapfelmeier of the TUM Institute of General Practice and Health Services Research. He notes that further research is needed to determine whether this association reflects a biological link—perhaps a degree of protection against certain infections—or whether it is due to behavioral differences in health care use among people who develop MS.
About this multiple sclerosis research news
Source: TUM
Contact: Bernhard Hemmer – TUM
Image: The image is in the public domain
Original Research: Closed access. “Systematic Assessment of Medical Diagnoses Preceding the First Diagnosis of Multiple Sclerosis” by Christiane Gasperi et al., Neurology
Abstract
Systematic Assessment of Medical Diagnoses Preceding the First Diagnosis of Multiple Sclerosis
Objective
This study examined the occurrence of medical diagnoses and symptoms during the five years before MS diagnosis, using a case-control design to compare patients later diagnosed with MS to several control groups.
Methods
Using large-scale ambulatory claims data, the researchers compared diagnostic codes recorded in the five years preceding first MS diagnosis for patients with MS (n = 10,262) against two other autoimmune conditions—Crohn disease (n = 15,502) and psoriasis (n = 98,432)—and a sample of individuals without these autoimmune diseases (n = 73,430).
Results
The analysis identified 43 ICD‑10 codes that occurred more frequently before MS diagnosis compared with controls without autoimmune disease. Many of these codes were consistent with symptoms suggestive of demyelinating events or other neurologic problems, and several findings were replicated when compared to the other autoimmune control groups. In a sensitivity analysis that excluded patients with explicit recordings of such neurological events before first diagnosis, the associations were no longer significant, supporting the interpretation that these earlier encounters reflected undiagnosed demyelinating episodes. Conversely, seven ICD‑10 codes were linked to lower odds of later MS diagnosis; four of these codes represented upper respiratory tract infections, a relation that became even stronger in sensitivity analyses.
Conclusions
The findings indicate that many patients experience clinically relevant neurologic symptoms and physician encounters years before a formal MS diagnosis, suggesting delayed recognition of initial demyelinating events rather than a distinct prodromal syndrome. The inverse association observed between upper respiratory tract infections and later MS diagnosis warrants further study to determine whether there is a protective link or whether other explanations account for this pattern. Overall, the study highlights opportunities to improve early detection of MS and to initiate appropriate treatment sooner.