Multiple sclerosis is a condition that affects a person's central nervous system. The body destroys protective myelin sheaths that are responsible for transmitting messages to nerve fibers. As a result, communication between a person's brain and the nerves are disrupted.
Eventually, the nerve fibers known as axons are also damaged. The disease can affect a person's movements and vision.
Multiple sclerosis (MS) is a disease that can develop in four different ways. The four types of MS are relapsing-remitting MS (RRMS), secondary progressive MS (SPMS), progressive-relapsing MS (PRMS), and primary progressive MS (PPMS). Each type is defined by symptoms that progress in a different way.
What is primary progressive MS?
Trouble maintaining balance may be one of the symptoms of PPMS.
Doctors characterize PPMS as a form of MS where neurological function gets consistently worse, without episodes of relapse or remission. However, some people with PPMS may experience temporary plateaus and sometimes minor reductions in symptoms.
PPMS is one of the more rare types of MS. Reports vary, but it is estimated that only about 10 percent of all people with MS go on to develop PPMS.
Unlike RRMS and SPMS, which are relapsing types of MS where the symptoms come and go, a person who has PPMS will experience a continued worsening of symptoms without any remission.
Typically, all types of MS cause damage to the central nervous system. But PPMS causes a different type of damage than the relapsing types of MS do. For example, people with PPMS tend to develop less brain lesions called plaques, but often have more lesions on the spinal cord.
According to the National MS Society, PPMS is more difficult to diagnose and treat than the relapsing MS forms.
People with PPMS usually develop their symptoms about 10 years later than those with relapsing types of MS. According to Johns Hopkins Medicine, doctors typically diagnose a person with PPMS when they are between the ages of 35 and 39.
Another key difference is that the relapsing types of MS affect two to three times more women than men, where PPMS affects both sexes in equal number.
Symptoms of PPMS
The condition can affect everyday life and a person's ability to complete daily tasks. One of the chief symptoms associated with PPMS is difficulty walking and this is thought to be linked to the damage to the spinal cord that is caused by PPMS.
Additional symptoms that a person with PPMS may experience include:
- Changes in mood
- Muscle weakness
- Problems thinking clearly
- Problems with bowel and bladder control
- Sexual dysfunction
- Trouble maintaining balance
- Trouble seeing
Many of these symptoms can occur with all types of MS, and distinguishing PPMS from other types can take time and repeated diagnostic tests. To be diagnosed with PPMS, a person must experience worsening symptoms associated with the condition over the course of a year.
MRI scans may be used to track the progression of MS.
In addition to progressive symptoms, a person must meet at least two of the following criteria:
- Experience lesions in the brain that are linked with multiple sclerosis as detected by a magnetic resonance imaging (MRI) scan
- Have two or more lesions associated with MS on the spinal cord
- Have the presence of elevated IgG antibodies or specific immune system proteins in the spinal fluid
A doctor will likely recommend regular MRI scans to track the progression of MS.
Despite lots of research into medication for PPMS, there are no drugs currently available that can treat this type of MS.
However, according to the National MS Society, one new drug known as ocrelizumab (OCR) has shown promise in a clinical trial to significantly reduce progression. In February 2016, the United States Food and Drug Administration (FDA) granted OCR "Breakthrough Therapy Designation" for PPMS. Hopefully, this drug will soon be approved for treatment of PPMS.
While there is no specific medication for PPMS, there are steps a person with PPMS can take to manage symptoms and enhance their quality of life.
Examples of these include:
- Medications to address specific symptoms a person with MS may be experiencing. Examples include medications for depression, muscle spasms, or bladder problems. These medications do not treat MS itself, but can minimize the symptoms it causes.
- Rehabilitation therapy to enhance strength, improve mobility, and promote independence whenever possible.
- Healthy living steps to promote physical and mental wellness. Examples include eating a healthful diet, exercising, and participating in counseling or group therapy.
In addition to these treatments, it is important for a person with any type of MS to avoid exposure to excessive heat temperatures. Overheating can cause the symptoms to worsen.
MS, and particularly PPMS, is an unpredictable disease with a very unpredictable course. The ultimate progression of the disease can be severe, and some people with PPMS may experience impairments or inabilities in walking, mood changes, balance problems, visual disturbances, bladder and bowel difficulties, and fatigue. The rate at which this progression occurs can vary from person to person.
According to an article published in the Journal of Neurology, Neurosurgery, and Psychiatry, the PPMS symptoms a person has and the age at which they are diagnosed with them can affect the rate at which the symptoms progress.
One of the methods used for gauging disability related to MS is the Kurtzke Expanded Disability Status Scale or EDSS. The numbers range from 0.0 (no symptoms) to 10.0 (death due to MS).
Some of the key functional differences on the scale include:
Currently, there is no medication available to treat PPMS, but there are steps a person may take to enhance the quality of their life.
- 4.0: Able to walk without using an assistive aid, such as a cane or walker. A person is able to be up and about for at least 12 hours a day without overly reduced function.
- 5.0: Able to walk without an aid for about 200 meters. However, a person's disability is severe enough to limit full daily activities, such as working full time.
- 6.0: Requires occasional or everyday assistance walking with a cane, crutch, or brace for distances of 100 meters or more.
- 7.0: Unable to walk 5 meters even with an aid. Usually requires a wheelchair.
- 8.0: Usually restricted to bed or chair or may require motorized wheelchair. A person at this phase will generally have effective use of their arms.
The transition from phase 4.0 to 5.0 usually represents a change in a person's ability to walk, which is one of the major symptoms a person with PPMS experiences.
According to an article published in the Journal of Neurology, Neurosurgery, and Psychiatry, the average time it takes for a person diagnosed with PPMS to reach EDSS 4 is 8.1 years. The time scale before a person with PPMS reaches EDSS 8.0 may vary, but on average it takes about 20.7 years. The speed at which symptoms progress is faster in PPMS than in the relapsing types of MS.