Does anyone know how long a relapse can last before it is no longer considered to be a relapse but is just general deterioration/progression? I was diagnosed with RRMS about 26 years ago and had many relapses which usually lasted for sevaral weeeks. 4 years ago I was told I am now SPMS. Since then I have had one or two fairly minor relapses. Since May last year I have been getting stiffness and spasticity in one leg. This continues to worsen, every week I seem to be worse than the week before. I have tried several drugs, so far nothing has helped. last week I saw a new neuro, he thinks this is a relapse. The continual, fairly rapid deterioration does seem a bit like a relapse but it’s been going on for 9 months. Is this possible for SPMS? Has anybody else had a relapse last this long, or longer?Thank you for reading this.