People with multiple sclerosis (MS) present themselves to a doctor much more often than other people, even years before diagnosis. Experts recently discussed this as a possible precursor phase of MS, a so-called prodromal phase. A research team at the Technical University of Munich (TUM) has now published study results suggesting that the symptoms are often unrecognized first flares of the disease.
People with the autoimmune disease multiple sclerosis can develop a number of different symptoms due to damage to the nervous system. Particularly in the early stages of the disease, these include sensory disturbances, for example numbness or visual disturbances. For most people, MS starts with relapses, i.e. symptoms appear and then disappear. Especially at the beginning of the disease the symptoms are manifold and so it is often difficult even for experienced physicians to interpret the signs correctly and to diagnose MS.
More doctor visits than average
However, it has been clear for some time that people with MS present to a doctor or seek hospital treatment far more often than people without MS years before they are diagnosed. This period before diagnosis has been considered in recent years by experts as a possible so-called prodromal phase.
"We believe that many complaints previously assigned to a prodromal phase are caused by the pre-existing disease itself."
Prof. Bernhard Hemmer
PD Dr. Alexander Hapfelmeier (l.) and Prof. Bernhard Hemmer (r.), Dean of the TUM Faculty of Medicine. Image: Andreas Heddergott/TUM
MS often begins long before diagnosis
A team at TUM around the neurologist Prof. Bernhard Hemmer has now shown in a new study that symptoms before diagnosis are unlikely to be such a prodromal phase. "Rather, we suspect that behind the reasons for presenting to the doctor, the first relapse events have already occurred," says Prof. Inhibitors. "This is because we found that there were more complaints present at doctor and clinic visits that indicated early symptoms of MS. We believe that many symptoms previously attributed to a prodromal phase are caused by the pre-existing disease itself. We therefore believe that the disease, although not yet diagnosed, is already fully active and not in a preliminary stage, the so-called prodrome."
"The earlier MS is detected, the better we can treat the disease."
Dr. Christiane Gasperi
On the way to earlier diagnosis
The new study results could thus also open up the possibility of optimizing MS therapy: "The earlier MS is detected, the better we can treat the disease," says first author Dr. Christiane Gasperi, physician and scientist at the Neuro-Head-Center at the Klinikum rechts der Isar of the TUM. "We now need to look more closely at what early symptoms of MS may be overlooked. This could help detect the disease earlier and thus initiate therapy sooner."
Rare infections of the respiratory tract
In addition to the described more frequent complaints in the years before an MS diagnosis, it was noticeable in this study that people with MS presented to doctors less frequently for upper respiratory tract infections. "This was an unexpected finding, especially since relapse events in MS have sometimes been associated with infections in the past," says co-first author PD Dr. Alexander Hapfelmeier of the Institute of General Medicine. Health services research at TUM. "However, whether there is a causal relationship between MS and some protection against some infections, or whether the analyzed care data reflect a protective behavioral change in ill individuals, is something we need to investigate in future studies."
Systematic Assessment of Medical Diagnoses Preceding the First Diagnosis of Multiple Sclerosis Christiane Gasperi, Alexander Hapfelmeier, Tanja Daltrozzo, Antonius Schneider, Ewan Donnachie, Bernhard Hemmer Neurology, 15. Jun 2021, 96 (24) e2977-e2988 DOI: 10.1212/WNL.0000000000012074
The study by Prof. Bernhard Hemmer, Dr. Christiane Gasperi and PD Dr. Alexander Hapfelmeier developed in the context of a collaboration with the Association of Statutory Health Insurance Physicians of Bavaria (KVB), which provided ambulatory care data of several thousand individuals in Bavaria for this study.