Does Multiple Sclerosis Cause Memory And Cognitive Problems?

I was told I had MS 25 years ago but was never given medicine. I have always been in remission. Tests of memory were given and the results were you are not to bad but they could not understand why I can not retain what I just read or why I take so much time before I could finish a task. There advise has been always not to stress to much. Be calm. I have to concentrate, read very slowly, and read again and again if I want to remember or talk about it with other people. Is memory and cognitive problems due to MS or is there a gene for memory and cognition.