85% or people with multiple sclerosis (MS) present with a relapse, which is a focal neurological deficit that reaches the greatest severity over a few hours or days with subsequent improvement over several weeks.
The first time this happens it is referred to as clinically isolated syndrome (CIS).
The recovery may be incomplete, so patients may continue to have residual numbness, paraesthesia, weakness, balance or visual problems but they will be better than they were at their worst.
Where the focal deficit is very severe the patient may need to be seen in the Emergency Department.
15% of people with MS present with a gradually progressive weakness in the legs or balance problems without any preceding relapses. A scan will then show evidence of prior inflammation.
People who have lots of different symptoms which come and go on a day-to-day basis usually don't have MS. A very small number do, but this can be investigated or ruled out using an MRI scan.
People who have MRI scans which show typical demyelinating lesions, but have had not symptoms which would be suggestive of MS, are sometimes said to have radiologically isolated syndrome (RIS).
A family history of MS does not significantly increase your absolute risk of MS, so is usually not relevant, Please see the MS FAQs page for more details.
Last reviewed: 05 September 2024