Multiple Sclerosis (MS) is a chronic, unpredictable autoimmune disease of the central nervous system. The immune system attacks the protective myelin sheath covering nerve fibers, causing communication problems between the brain and the body. For those newly diagnosed, questions about the disease’s long-term impact, especially longevity, are a primary concern. Modern understanding and effective treatments offer a far more optimistic outlook than in previous decades. This article analyzes current data on life expectancy and the factors influencing the long-term prognosis for individuals living with MS.
Life Expectancy Statistics
Current research indicates that Multiple Sclerosis reduces a person’s average life expectancy by a small margin compared to the general population. Studies consistently suggest that the reduction in lifespan typically falls within the range of five to seven years. For example, a Norwegian study found the median life expectancy for people with MS was 74.7 years, compared to 81.8 years for the general population, a difference of 7.1 years.
The historical context is important, as the life expectancy gap has been steadily closing. Much of the data includes individuals diagnosed before the advent of modern disease-modifying therapies (DMTs). DMTs became widely available in the mid-1990s and are designed to reduce relapse frequency and slow disability accumulation. The introduction of these therapies has changed the disease’s trajectory. Newer studies reflect this positive shift, showing that individuals receiving DMTs have a significantly lower mortality risk.
Factors Influencing Long-Term Prognosis
The long-term prognosis is influenced by several disease-specific and demographic factors.
Initial Disease Course
One significant variable is the initial disease course. Individuals with Relapsing-Remitting MS (RRMS), which accounts for about 85% of initial diagnoses, generally have a more favorable long-term outlook than those with progressive forms. Patients with Primary Progressive MS (PPMS) or Secondary Progressive MS (SPMS) typically face a less favorable prognosis and shorter life expectancy compared to those with RRMS.
Age of Onset
The age at which symptoms first appear also plays a role in long-term survival. A younger age of onset (before age 40) is associated with a longer overall lifespan because disability accumulates more slowly. Conversely, an older age at diagnosis is linked to a more rapid progression and a poorer survival rate.
Early Treatment
Early treatment initiation is a major predictor of a better outcome. Starting DMTs soon after diagnosis is crucial because these medications reduce inflammatory damage to the central nervous system, slowing the rate of long-term disability accumulation. Clinical markers, such as a high number of relapses or a rapid increase in disability early in the disease course, are associated with a less favorable prognosis.
Mortality Risks and Causes of Death
Multiple Sclerosis is rarely the direct cause of death. Mortality is linked to complications arising from advanced disability, which are secondary to the disease’s effects on mobility and bodily functions.
Infections
Infections are a significant risk, particularly respiratory and urinary tract infections. Decreased mobility and advanced disability can impair lung function and increase the risk of aspiration pneumonia (inhaling food or fluid). Such infections are often the immediate cause of death listed on the death certificate.
Cardiovascular Disease
Cardiovascular disease is a leading cause of death, similar to the general population, though people with MS have a higher relative risk. This increased risk is attributed to a more sedentary lifestyle resulting from mobility issues.
Mental Health Concerns
Mental health concerns also pose a risk. The prevalence of depression and the rate of suicide are notably higher in the MS population compared to the general public.