Prognosis means the likely course of a health condition, based on medical experience.
It is very difficult to predict the course of multiple sclerosis. The type, duration, severity and impact of symptoms will vary from individual to individual. Some people will go for long periods with few or no symptoms whilst others will experience more frequent or persistent problems.
There are some factors that have been shown to suggest how MS may develop. These have been observed in long-term studies and reflect a general trend. They do not represent a guide to how a specific person's MS will develop. Multiple sclerosis remains a very unpredictable condition.
Factors that are associated with a relatively better disease course are:
- being female
- being less than 40 years old when diagnosed
- having few relapses in the first few years after diagnosis
- making a complete recovery from relapses
- having long intervals between relapses
- having symptoms that are mainly sensory in nature (such as numbness or tingling).
Many people diagnosed with MS take steps to improve their general health, such as altering their diet or taking more exercise.
There is no direct evidence to link dietary interventions or supplements to improved prognosis in MS. However, it is possible to reduce your risk of co-morbidities through healthy living. For example, there is a link between a Mediterranean type diet and reduced vascular disease. Vascular disease co-morbidities are associated with increasing disability in MS, and can lead to lowered life expectancy and increased EDSS (disability) score.
Research suggests that people with MS have mixed feelings about knowing their likely disease course. For some people with MS, they aim to live in the moment and try not to worry about what the future might hold, so they avoid finding out too much about later stage MS. However, for other people with MS, knowing their prognosis could reduce their anxiety from not knowing what's likely to happen, and enable them to make plans.
Before the current era of effective disease-modifying drugs (DMDs), the only treatment would have been to alleviate MS symptoms, and knowing your prognosis would not change any of that treatment. However today, having a clear idea of the disease pathway you are likely to be on might shape your decisions about what kind of DMD is appropriate for you. You might be more likely to opt for the highly effective and higher risk DMD options if the evidence suggested that you would be likely to experience a worse disease course. If you knew the likelihood was that you were not going to experience extreme symptoms or disability, then you might stick to low-risk but lower efficacy treatments.
Much research effort is currently aimed at answering this question, looking at factors like brain volume and optic nerve size in an attempt to find markers that might be linked to better or worse disease pathways. It is still early days, but the aim is to help people understand their likely prognosis and make it easier for them to choose the right treatment.