Multiple Sclerosis Prognosis and Life Expectancy

Multiple sclerosis (MS) is a neurological disorder caused by the body’s immune system erroneously attacking myelin, a fatty covering around nerve fibers. The resulting neurological damage can cause a number of MS symptoms, including fatigue, muscle spasms, balance issues, and vision problems.

Depression, trouble controlling the bladder or bowel, and difficulties with sexual health also are common in people with the disease.

MS itself is not usually fatal. However, the disorder may increase the risk of life-threatening complications, such as severe infections or swallowing difficulties, that can set the stage for pneumonia.

On average, the lifespan for people with MS is about five to 10 years shorter than for the general population, but this gap is getting shorter as treatments and care continue to improve.

Most people with MS experience two stages of disease. The first stage is relapsing-remitting MS (RRMS), which is characterized by episodes of new or worsening symptoms (relapses), interspersed with periods of partial or complete recovery from symptoms (remission).

Most RRMS patients will gradually enter a progressive phase of disease, called secondary progressive MS (SPMS), in which symptoms continually worsen over time, even when no relapses occur.

The time it takes to progress from RRMS to SPMS often varies substantially from person to person and potentially can be influenced by the use of disease-modifying therapies (DMTs). If left untreated, about half of RRMS patients would progress to SPMS within 10 years of disease onset. But when most patients received treatment, only about 10% converted to SPMS, and over a median of 32 years.

In approximately 15% of MS patients, the disease will enter a progressive phase immediately, with symptoms that continually get worse over time. This disease form is referred to as primary progressive multiple sclerosis (PPMS).

In general, symptoms worsen more quickly in progressive forms of MS (SPMS or PPMS) than in relapsing disease.

Although MS is often categorized as either “relapsing” or “progressive,” these categories are far from absolute and may overlap. People with progressive MS can experience disease relapses and periods of relative remission, while individuals with relapsing disease may experience some symptom progression between relapses.

EDSS: Measuring disability progression

Disability progression in people with MS is most commonly tracked with a standardized measure called the Expanded Disability Status Scale, or EDSS. This scale ranges from 0, indicating no disability, to 10, for death. Scores increase in increments of 0.5 as disability progresses.

From scores of 0 to 4.5 in the EDSS, individuals are able to walk without any aid and their disability is measured based on impairments in functional systems. These systems represent groups of nerves responsible for specific tasks. Each is graded on a scale of 0 (no disability) to 5 or 6 (severe disability).

The EDSS assesses eight functional systems:

• pyramidal: muscle weakness or trouble moving the limbs
• visual: problems with vision
• cerebellar: tremor, loss of balance, and coordination problems
• brainstem: uncontrolled eye movements and difficulty talking or swallowing
• sensory: numbness or unusual sensations
• bowel and bladder: changes in gastrointestinal and urinary tract function
• cerebral: difficulty with thinking or memory
• other: any other neurologic finding attributed to MS

From scores of 5 to 9.5, the EDSS is assessed mainly based on an individual’s ability to walk.

No two people with MS experience exactly the same symptoms or patterns of disease progression. Much like there are risk factors for developing MS, there are varying components that also can affect the disease course. These include:

• treatment
• lifestyle factors
• biological traits
• disease-intrinsic factors
• demographics, such as race and sex

Treatment

Perhaps the most important factor that affects the trajectory of MS in the modern day is treatment. Disease-modifying therapies, known as DMTs, are currently approved in the U.S. and several other countries for all the main MS types.

Beginning treatment as early as possible is highly recommended for MS patients. Long-term outcomes are generally better for patients who start treatment early in the course of their disease.

All currently approved DMTs work by reducing the inflammatory attack that drives MS. These medications have been proven in clinical trials to reduce disease activity — by lowering relapse risk, preventing new damage in the brain, and/or slowing the accumulation of disability.

Each of the available treatments has its own safety and efficacy profile, and patients are advised to talk to their healthcare team about whether certain medications might benefit them.

Lifestyle factors

A number of lifestyle factors can affect the progression of MS. For example, more physical exercise has been linked to both better physical and cognitive outcomes over time. Depending on the kind and duration of exercise, patients also may experience less brain tissue degeneration and fewer relapses.

People with MS should also take smoking into account, as a number of studies have shown that the disease tends to be more severe in people who smoke cigarettes. MS patients who smoke are typically advised to try and quit or cut back.

Dietary habits also have a substantial impact on MS, although the nuances are still not fully understood. While there isn’t any “optimal diet” for people with MS, consuming lots of fruits and vegetables, more whole grains, a variety of lean proteins, and less processed food or refined sugar is usually recommended.

Chronic stress also has been noted as a potential contributor to MS relapses and disability progression. Stressful events that contribute to a disruption in routine have been associated with the development of new inflammatory brain lesions.

Biological and disease-related factors

An individual’s age at MS symptom onset has been shown to be a main factor in determining the course of MS. In general, the older the age at onset, the faster the disease progresses. However, the frequency of relapses over a person’s lifetime usually is greater in people diagnosed at younger ages.

The early course of MS also provides prognostic information about how the disease is likely to progress. Experiencing more relapses or a substantial increase in disability early in the disease course is associated with a higher risk of severe disease progression and cumulative disability.

Measuring inflammation and damage in the nervous system via MRI scans also can help to provide prognostic information about the likely disease course. Typically, greater damage on such scans is broadly tied to more severe symptoms and disability.

Obesity – a body mass index higher than 30 – has been linked to a more severe disease course. This is most likely because more adipose tissue, or body fat, leads to chronic inflammation in the body, which contributes to further nerve damage in MS.

Demographic factors

Race and ethnicity have also been shown to affect MS severity. In the U.S., MS patients who are Black or Latin American tend to have more severe disability worsening and a higher death rate. These differing outcomes are thought to be driven by interconnecting factors including genetic differences, geographical location, and socioeconomic disparities.

While the disease is less common in men than in women, males tend to have a poorer prognosis than females. Males generally experience worse recovery after relapses, have higher rates of brain damage and cognitive impairment, and are more likely to develop progressive forms of MS and become substantially disabled.

In females, relapses and brain lesions are more common than in males, but females tend to have fewer brain lesions with permanent nerve damage. Some MS symptoms also vary by sex. For example, motor symptoms are generally more common in males, while vision problems are more common in females.

After an MS diagnosis, patients and their healthcare teams typically will work together to come up with a care plan suited to the individual. This often involves:

• regular appointments with a neurologist to monitor disease progression.
• the use of DMTs to prevent relapses and slow the progression of MS.
• other medications or therapies to help manage individual symptoms.

Certain changes in lifestyle also may help some MS patients to better manage their disease. These can include:

• quitting smoking.
• exercising and losing weight.
• finding strategies to reduce stress.

Multiple sclerosis is a lifelong disease, and disease manifestations vary substantially from person to person. For some people with MS, the disease causes noteworthy disability shortly after it manifests, whereas others may go decades without ever developing symptoms that substantially interfere with their daily life.

With modern care, most patients retain a fair degree of mobility throughout their lives. It is estimated that about two-thirds of patients are still able to walk some 20 years after being diagnosed, although some may require assisted devices, such as supports to aid in walking, or scooters used on occasion to save energy and avoid fatigue.