How and when does multiple sclerosis begin? Does the disease begin with the first relapse or is this first relapse preceded by a so-called prodromal phase, during which the disease already exists, but does not yet lead to neurological failures? This important question, which has so far been little discussed in the literature, was addressed by Canadian MS specialist Helen Tremlett. She presented her considerations on this topic and her scientific work in the opening lecture of this year’s ECTRIMS Congress.
With the help of the Canadian MS Registry and comparable control persons from the national health register, it was examined whether MS patients already show a different behavior in the use of health services before the diagnosis of multiple sclerosis (i.e. before the first disease relapse) than the selected control persons. Furthermore, it was investigated what the reasons were for using health services.
For this purpose, the health behavior of 14,000 MS patients in the 5 years before the first MS relapse was compared with the health behavior of 72,000 matched controls. Surprisingly, compared to the normal population, MS patients consistently used more health services. In the year before the first clinical event, MS patients had a 78% higher rate of hospital admissions, an 88% higher rate of doctor visits, and about a 50% higher prescription rate for medication. Based on this data, it could be assumed that the first clinical relapse is actually preceded by a prodromal phase. Broken down by symptoms, it was primarily psychiatric problems that led to the use of health services. Interestingly, services were also used for dermatological symptoms, raising the question of whether skin changes have significance before the first relapse. In female MS patients, an increased intake of contraceptives and a decreased incidence of pregnancies were also observed. All these findings leave much room for speculation and are definitely not yet proof of a prodromal phase in MS. On the other hand, the Canadian observations were supported by further studies from Norway and Germany, among others.
If there would be a – however defined – prodromal phase of MS, this would have significant implications for the early detection of MS. In particular, the identification of a prodromal stage would provide a significantly larger “window of opportunity” for the management of MS – an even earlier and thus, according to current knowledge, more efficient treatment of MS would be possible. On the other hand, the prodromal symptoms identified by Helen Tremlett’s team are clinically relatively unspecific. However, this problem could be relativized by the future use of biomarkers. My next post here will be about biomarkers.
In any case, in my opinion, the considerations regarding prodromal MS influence the approach to the so-called radiologically isolated syndrome (RIS) – i.e. only MRI changes without specific clinical symptoms. Perhaps, in knowledge of the work on prodromal MS, therapeutic intervention should be more consistent in these individuals and not wait for the first relapse.
