I am often asked in the consultation hour: “Do I now have a relapsing or a chronic-progressive course.” And usually, this question is posed by younger patients who have recently been diagnosed with MS. There is probably always a bit of fear involved, because in many texts and treatises on MS, the chronic-progressive course is mentioned in the same breath as a poor prognosis and a poorer ability to respond to therapy. Basically, it can be said that well over 80% of all MS cases begin as typical relapsing forms. If MS is not adequately treated, i.e., if relapses and MRI activity are tolerated at the beginning, one must expect that after 10 – 15 years about two thirds of the relapsing courses will turn into so-called secondary chronic-progressive form. We therefore speak of “secondary” because the disease started “primarily” as a relapsing form.
There is also the so-called primary chronic-progressive MS, which is rare and affects only about 10% of all MS patients. The primary chronic-progressive MS is characterized by the fact that it usually only begins around the age of 40, affects men and women equally often (the classic MS affects women much more frequently) and often leads to a slowly progressive walking disorder due to a primary involvement of the spinal cord. To this day, it is not entirely clear whether primary chronic-progressive MS might even represent a different disease, as it is not particularly accessible to immune therapies compared to typical relapsing MS.
The secondary chronic-progressive MS is a common problem for long-term MS patients, as it is – as mentioned above – the consequence of long-standing relapsing MS. Our understanding of the development of the secondary chronic-progressive course is that early in the course of the disease – in case of inadequate control of inflammatory activity – a slowly progressing neurodegenerative process (degradation process) is set in motion, which then dominates the course of the disease in later phases (when relapses recede into the background). Therefore, we currently see the most promising possibility of preventing the transition to a secondary chronic-progressive form in a consistent anti-inflammatory therapy at the beginning of the disease. If the therapy comes too late, or if the therapy is not strong enough to stop the inflammatory activity early on, the continuous tissue destruction takes its course and eventually leads to a progressive increase in neurological deficits, which are then also therapeutically not so easily accessible.
How can you tell that MS has transitioned to a secondary chronic-progressive form? Well – you have to understand first that we are not talking about a defined point in time, the transition to a secondary chronic-progressive form rather describes a period that can extend over several years. During this time, the patient notices that mobility, but also other important functions such as cognition or bladder function, continuously deteriorate – this finding then slowly progresses over many years. It is worthwhile to work against this slow degradation with symptomatic therapy measures, especially non-drug measures such as physiotherapy, occupational therapy, speech therapy. With intensive rehabilitation efforts, often astonishing successes can be achieved. Only when the deterioration really progresses very rapidly should one consider intensifying the drug-based immune therapy with the neurologist. Of course, we also hope that new therapeutic approaches will soon be available that have neuroprotective aspects – but so far we are still waiting for a breakthrough here. Also against this background of limited possibilities of therapy for MS that has transitioned into a secondary chronic form, it may be understandable why many MS experts repeatedly emphasize how important early and consistent MS therapy is. It is an essential strategy to prevent a later chronic progression of MS.
