Overview of Progressive-Relapsing Multiple Sclerosis (MS)

Primary progressive MS (PPMS), the now-preferred name for what some still call progressive-relapsing multiple sclerosis (PRMS), is the least common type of multiple sclerosis (MS). It affects about 10% of people who have the disease and produces a gradual decline in physical abilities. This begins early in the disease course, with only a few MS exacerbations or none at all.

The treatment of PPMS differs slightly from treatment for other MS types because relapses are not a major part of the condition. Many of the disease-modifying therapies (DMTs) approved for other types of MS are not approved for primary progressive MS.

Symptoms

There are four types of MS—clinically isolated syndrome (CIS), relapsing-remitting MS (RRMS), secondary progressive MS (SPMS), and PPMS. The main difference between these four types is the frequency and progression of symptoms.

The symptoms of PPMS do not improve the way the symptoms of some other MS types do. Generally, the symptoms of PPMS worsen over time, and the decline does not necessarily always happen at a smooth and steady pace. Effects like weakness and vision loss can deteriorate in a choppy manner, with abrupt declines and intermittent periods of stability.

Symptoms of PPMS can include:

• Diminished vision of one or both eyes
• Muscle weakness 
• Trouble with balance and coordination 
• Slurred speech
• Trouble swallowing 
• Difficulty walking
• Decreased sensation 
• Tingling, numbness, or pain 
• Trouble urinating—urinary retention (can’t urinate) or incontinence (bladder accidents) 

If you have PPMS, you can have exacerbations, but your overall physical abilities are expected to decline even in the absence of them. And sometimes, a person who has PPMS may not have any exacerbations at all. 

Illnesses, such as a cold or a more serious infection, may worsen PPMS symptoms. The deterioration elicited by these triggers can last for weeks.

Symptoms of PPMS can temporarily worsen with hot weather and even with hot baths.

Causes 

MS is caused by the demyelination of the central nervous system. Myelin is a coating composed of fat molecules. It protects nerves so they can transmit their electrical signals to each other efficiently.

Demyelination is the loss of myelin from around these nerves. Because demyelination makes it difficult or impossible for nerves to transmit signals, neurological symptoms appear.

In MS, demyelination affects parts of the brain, spinal cord, and optic nerves (the nerves that control vision). The demyelination of MS is believed to result from an inflammatory process in which the body attacks its own myelin. This is described as an autoimmune process (the body’s immune system attacking itself). 

PPMS and Nerve Damage

Generally, the body renews myelin on a regular basis, which explains the recovery in CIS and RRMS. However, myelination and neurological function do not improve in PPMS, and experts suggest that the nerves may become permanently damaged in this type of MS. 

Another difference between PPMS and other types of MS is that there is not as much inflammation in PPMS. Experts suggest that there could be another cause of demyelination in PPMS besides inflammation.

Diagnosis 

The diagnosis of PPMS relies on your clinical history and diagnostic tests. 

If your symptoms are characteristic of MS, you will likely have magnetic resonance imaging (MRI) performed on the brain and/or spine. These imaging tests can show lesions that appear as demyelination. Typically, MS is characterized by more than one demyelinating lesion.

A lumbar puncture may also be used. Also called a spinal tap, this is an interventional diagnostic test used to collect a sample of spinal fluid. Your healthcare provider would collect the sample using a small needle that is placed in your lower back. The procedure can be somewhat uncomfortable, but it is safe and can be very useful.

The fluid sample is sent to a lab for analysis. Spinal fluid in MS may contain immune proteins called oligoclonal bands.

CIS is a one-time MS-like event that completely or almost completely improves. If the symptoms of CIS recur after resolving, the diagnosis becomes RRMS, which is characterized by episodes of disease exacerbations with some recovery in between.

If the symptoms of CIS do not improve, then it is often the beginning of PPMS, which can start with mild, moderate, or severe effects that don’t resolve. SPMS occurs if RRMS becomes progressive.

Treatment

There are a number of treatment approaches used in MS. The disease is treated with disease-modifying treatments (DMTs) that are taken on a regular schedule to prevent exacerbations and progression.

Disease effects, such as pain, are managed with specific medications or therapies, and exacerbations are typically treated with short-term, high-dose steroids.

DMTs

Only one DMT, Ocrevus (ocrelizumab), is approved for PPMS.

If your healthcare provider thinks that you would benefit from a DMT that is not approved for your condition, they may recommend it for off-label use. Oftentimes, medications are safely used off-label with good clinical benefits.

Symptomatic Treatment

With PPMS, you can have a number of lasting effects that need to be treated.

There are medications and bladder exercises for the management of urinary retention and incontinence. You can also take medication if you experience pain. For weakness, you can often use braces for muscle support.

Frequently, physical therapy can be helpful to optimize your balance, muscle control, and strength. Tailored exercises can be beneficial if you have trouble with chewing or swallowing. With PPMS, you may need to continue physical therapy for many years. 

At-home exercises and participation in group exercises and fitness classes can help maintain your physical abilities, particularly if you have only mild effects of PPMS. 

Treatment for Exacerbations 

While MS exacerbations are not common in PPMS, they can occur. If you experience a major episode, your medical team will consider treatment with intravenous (IV) steroids.

This often helps hasten recovery and may reduce the long-term effects of an MS attack. In some instances, plasmapheresis (a procedure involving plasma exchange) is considered. 

A Word From Verywell

Because PPMS is the least common type of MS, it can be difficult for you to know what to expect. Some people who have PPMS can have a mild and very slow decline, while the disease can progress more rapidly for others. In general, many of the things you see and hear about MS simply may not apply to you.

Consider asking your medical team about nearby support groups so you can connect with others with PPMS. While your experiences won't be exactly the same, you may share some common ground that can help you better understand your disease and ways to live well with it.