Persons suffering from the autoimmune disease multiple sclerosis can develop various neurological symptoms caused by damage to the nervous system. Especially in early stages, these may include sensory dysfunction such as numbness or visual disturbances. In most patients, MS starts with recurring episodes of neurological disability, called relapses or demyelinating events. These clinical events are followed by a partial or complete remission. Especially in the beginning, the symptoms vary widely, so that it is often difficult even for experienced doctors to interpret them correctly to arrive at a diagnosis of MS.

Above-average numbers of medical appointments

It has been evident for some time, however, that patients with MS show significantly higher numbers of physician visits and hospital admissions even years before the first diagnosis as compared to healthy control persons. In recent years, specialists have seen this pre-diagnosis period as a possible prodromal phase of the disease.

MS often begins far in advance of the diagnosis

A new study carried out by a team working with the neurologist Prof. Bernhard Hemmer at TUM suggests that many complaints prior to diagnosis might not represent a prodromal phase. "Instead, we suspect that unrecognized MS relapses cause these individuals to seek medical attention," says Prof. Hemmer. "That is because we have found that the physician appointments and hospital admissions frequently involved complaints indicating typical MS symptoms. We believe that many complaints that have been attributed to a prodromal phase are in fact caused by ongoing disease. We therefore believe that, although the disease has not yet been diagnosed, it is fully active and not in a preliminary or prodromal phase."

A path to an earlier diagnosis

The results of the study could also open up possibilities to optimize MS treatment: "The sooner MS is recognized, the better we can treat the disease," says first author Dr. Christiane Gasperi, a physician and researcher at the Neuro-Head Center at the TUM Klinikum rechts der Isar. "We now need to take a closer look at which early symptoms of MS might be overlooked. This could allow us to recognize the disease at an earlier stage and thus enable earlier treatment initiation."

Less frequent respiratory tract infections

Along with the more frequent complaints in the years before an MS diagnosis, the results of the study also showed that persons with MS were actually less likely to seek medical attention for upper respiratory tract infections. "This was unexpected, in view of the fact that MS relapses have sometimes been associated with infections," says co-first author and Adjunct Teaching Professor Dr. Alexander Hapfelmeier of the TUM Institute of General Practice and Health Services Research. "However, future studies will be needed to determine whether there is a causal link between MS and a degree of protection against certain infections, or whether the health data we analyzed reflect protective behavior adopted by persons with MS."