Multiple sclerosis (MS) affects everyone differently, especially because there are several types of MS. Some people may be diagnosed with clinically isolated syndrome (CIS), while others may have relapsing-remitting MS (RRMS) or secondary progressive MS (SPMS).

In this article, we’ll focus on another subtype of MS called primary progressive MS (PPMS) and what it can mean for prognosis and life expectancy.

How Does MS Affect the Brain?

MS is a chronic autoimmune disease in which the immune system attacks components of the central nervous system (CNS), which includes the brain, spinal cord, and optic nerves. A common feature of MS is the destruction of the myelin sheath — the protective coating around nerve cells — by cells in the immune system.

When the immune system destroys myelin, it disrupts how nerve cells function and communicate. This can affect your body’s ability to send and receive sensory, motor, and cognitive information. Over time, the damage leads to lesions in the brain and spinal cord, which can be seen on MRI scans.

Is PPMS the Worst Form of MS?

Whether PPMS is the “worst” type of MS depends on each person’s experience and symptoms. Still, PPMS often causes more motor problems (problems with movement) than other forms of MS.

People with PPMS usually have more lesions on the spinal cord than in the brain. Because of this, people with PPMS have more motor symptoms such as weakness, stiffness, and walking difficulties than people with other forms of MS. Unlike relapsing forms of MS, PPMS is marked by gradually worsening symptoms, without clear periods of relapse and recovery.

PPMS is relatively rare and only affects about 10 percent of people with MS. While women are about three times more likely to develop a relapsing form of MS, PPMS happens equally in men and women. PPMS can be harder to diagnose at first than other forms of MS, and it may also be more difficult to treat.

What Is the Prognosis for People Living With PPMS?

Living with PPMS can bring many challenges. The symptoms and how quickly they progress can vary from person to person. Common symptoms of PPMS include:

• Trouble walking
• Paralysis
• Muscle weakness
• Balance problems
• Changes in vision
• Lhermitte sign (an electric shock sensations in the back or limbs when you bend your neck)
• Headaches
• Pain in the arms or legs
• Numbness
• Tingling in the fingers
• Dizziness
• Mood changes
• Depression
• Bowels and bladder problems
• Brain fog
• Sexual dysfunction
• Fatigue

People with PPMS often experience more disability, including problems with walking and employment, compared to those with relapsing forms of MS. This is partly because PPMS doesn’t have periods of remission. Without remission, damage to the CNS can build up more quickly over time.

How long do people live with PPMS? Prognosis of PPMS can depend on the age when symptoms first appear. People diagnosed with PPMS at a younger age may have slower disease progression.

Can You Live a Normal Life With PPMS?

In some ways, yes. Many people with PPMS keep their thinking and memory abilities intact. However, PPMS most often affects motor function.

PPMS is usually diagnosed later in life — about 10 years later, on average, than relapsing forms of MS. This means many people with PPMS live more years without symptoms before their diagnosis.

Because lesions in PPMS tend to affect the spine more than the brain, symptoms are often related to movement, such as difficulty walking. People with PPMS usually have fewer symptoms related to thinking, memory, and cognition than people with relapsing MS.

Some people with PPMS may need to rely on assistive devices as their disease progresses. This could mean using a walking cane, walker, or wheelchair. On average, it takes 12.1 years for someone with PPMS to begin using a wheelchair.

Influencing Prognosis: Treatments for PPMS

Are there disease-modifying therapies for PPMS? So far, the U.S. Food and Drug Administration (FDA) has only approved one medication for the treatment of PPMS: ocrelizumab (Ocrevus and Ocrevus Zunovo).

Ocrelizumab is a monoclonal antibody therapy that targets B cells. B cells are a type of immune cell that can contribute to PPMS by activating immune cells that attack the CNS, causing inflammation and damage. By reducing B cells, ocrelizumab has been shown to slow disability in people with PPMS. In clinical trials, people receiving ocrelizumab were able to delay their need for a wheelchair by an average of seven years.

Doctors may also prescribe other medications to manage symptoms of PPMS such as depression, pain, fatigue, bladder control, or sleep issues. Lifestyle changes, including a healthy diet and regular exercise, may also improve prognosis. Physical, recreational, occupational, and speech therapy can also improve disease outcomes related to PPMS.

Life Expectancy With PPMS

Although there’s no cure for PPMS, the condition isn’t considered to be fatal. Most people with PPMS die from common causes such as cancer or heart disease.

How Long Can You Live With MS?

On average, the lifespan of people with any form of MS is seven years shorter than the lifespan of those without MS. Some studies have shown that life expectancy may be even lower in people with PPMS. Unlike relapsing forms of MS, which affect women more than men, PPMS affects men and women equally. However, on average, women diagnosed with PPMS have shorter lives than men with PPMS.

The good news is that medical research is always advancing and evolving. As researchers learn more about the immune system, the CNS, and PPMS, new treatments for this condition are being developed and tested to improve life expectancy and quality of life.

Talk With Others Who Understand

On MyMSTeam, people share their experiences with multiple sclerosis, get advice, and find support from others who understand.

Do you have PPMS? Let others know in the comments below.