Multiple Sclerosis (MS) is a chronic, unpredictable neurological disease affecting the central nervous system. The immune system mistakenly attacks the protective myelin sheath covering nerve fibers, disrupting communication between the brain and the body. While MS is serious, it is generally not considered a direct cause of death. However, severe disease progression can lead to life-threatening complications that indirectly shorten a person’s lifespan.
Understanding MS and Lifespan
MS does affect longevity, though not as severely as often perceived. Life expectancy for people with MS is, on average, shorter by about seven years compared to the general population. This gap is continually narrowing due to advancements in treatment and better medical care.
The vast majority of individuals diagnosed with MS live long lives. Studies comparing life expectancy often show median survival differences, such as 74.7 years for those with MS versus 81.8 years for the general population in one large study. This difference represents a reduction in the quantity of life, not an immediate fatal outcome, reflecting the success of disease-modifying therapies and comprehensive symptom management.
Common Fatal Complications
Fatal outcomes in MS typically result from secondary complications arising from long-term, severe disability and immobility, rather than the disease process itself.
Infections stand out as the most common immediate cause of death for people with advanced MS. Respiratory infections, such as aspiration pneumonia, are particularly concerning, occurring when swallowing difficulties (dysphagia) allow food or liquid to enter the lungs. Weakened respiratory muscles, resulting from severe neurological impairment, also make it harder to clear the lungs and fight off infections.
Another serious infectious complication involves the urinary tract, where recurrent urinary tract infections (UTIs) can progress to sepsis. Bladder dysfunction is common in MS, and if not managed properly, these infections can become increasingly severe. Cardiovascular disease also contributes significantly to mortality in the MS population.
Reduced mobility and a sedentary lifestyle amplify the risk of heart disease and stroke. People with MS have a higher relative mortality rate associated with vascular diseases compared to the general population. Severe disability can also lead to secondary issues like pressure sores or injury from falls, which increase the risk of infection.
Disease Characteristics Affecting Survival
The risk of experiencing severe, life-limiting complications is not uniform across all individuals with MS; it is heavily influenced by specific disease characteristics. The subtype of MS plays a large role in long-term prognosis. Progressive forms, specifically Primary Progressive MS (PPMS) and Secondary Progressive MS (SPMS), are associated with greater disability accumulation and a higher mortality risk compared to Relapsing-Remitting MS (RRMS).
PPMS has been shown to have a shorter life expectancy compared to RRMS in some studies. For instance, one large study found the life expectancy for RRMS patients was 77.8 years, while for PPMS patients it was 71.4 years. The rate at which a person accumulates disability is another factor that influences survival.
Individuals who experience a rapid accumulation of disability, often measured by reaching a high score on the Expanded Disability Status Scale (EDSS), face a higher risk of complications. The age at which symptoms begin also affects the outlook. Some analyses suggest that diagnosis at a very young (under 20) or older age (over 60) may be associated with increased mortality compared to those diagnosed in middle adulthood.
Proactive Management for Longevity
The most significant factor in improving longevity for people with MS is the proactive management of the disease and its associated risks. Adherence to Disease-Modifying Therapies (DMTs) is a cornerstone of this approach, as these treatments slow disease progression and reduce long-term disability accumulation. Studies show that people with MS who take DMTs have a reduced mortality risk compared to those who do not.
Specific interventions mitigate the risks of common fatal complications. Regular physical therapy helps maintain mobility and muscle strength, reducing the risk of cardiovascular issues and pressure sores. Swallowing assessments by a speech-language pathologist can identify dysphagia early, allowing modifications to prevent aspiration pneumonia.
Diligent bladder health management, which may include medication or intermittent catheterization, is necessary to prevent recurrent UTIs that can lead to sepsis. Managing overall health is paramount, including lifestyle factors like maintaining a healthy weight and avoiding smoking. Treating co-existing conditions like high blood pressure is also essential to reduce cardiovascular risk.