Symptoms of Primary Progressive Multiple Sclerosis (PPMS)

Man suffering from primary progressive multiple sclerosis standing near steps
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Primary progressive multiple sclerosis (PPMS) affects as many as one in eight people living with multiple sclerosis. Of the various types of the disease, PPMS is considered the rarest.

How PPMS Differs From Other Forms of MS

The most common form, known as relapsing-remitting MS (RRMS), is characterized by acute attacks followed by periods of remission where the disease doesn’t progress. When it does progress, a person is said to have secondary progressive (SPMS).

PPMS, by contrast, is progressive from the start. A person diagnosed with PPMS does not have the typical flares or relapses associated with RRMS or SPMS. Instead, symptoms arise gradually and are not reversible.

As with other forms of multiple sclerosis, the course of PPMS is highly variable, affecting each person differently. Some may become disabled within a few years whereas others remain stable for decades.

Symptoms Related to the Spinal Cord

In terms of symptoms, people diagnosed with PPMS will most often experience walking problems due to the progressive atrophy (wasting and degeneration) of the spinal cord. Also known as progressive myelopathy, the symptoms may include:

  • An increasingly spastic gait referred to as spastic paraparesis, in which the legs will begin to stiffen, causing a visible limp and/or rhythmic jerkiness
  • A weakness or immobility on one side of the body, known as spastic hemiparesis, which may affect the legs, arms, or hands
  • Exercise intolerance (the decreased ability to perform exercise)
  • Clumsiness and lack of muscle coordination (ataxia)

When the spinal cord is affected by the disease, it can interfere with more than just movement. It can cause impairment of sexual, bladder, and bowel function. Fatigue is also common with this and all other forms of multiple sclerosis.

Symptoms Related to the Brain

While the spinal cord is the main target of injury in PPMS, the brain may also be affected, primarily the part known as the cerebellum which regulates balance and coordination. Known as progressive cerebellar syndrome (PCS), the disorder affects one of every 10 persons diagnosed with PPMS and can often manifest with:

  • Impairment of fine hand movement due to severe intention tremor
  • Loss of muscle tone (hypotonia)
  • Loss of balance (gait ataxia)
  • Inability to coordinate movement (dysmetria) where a person either overshoots or undershoots the intended position of the arm, leg, or hand
  • Inability to perform rapidly alternating movements (dysdiadochokinesia) such as screwing in a light bulb

Inflammation and neurodegeneration appear to be the main mechanisms underlying the cerebellar and spinal cord involvement in PPMS patients.

Uncommon Symptoms of PPMS

While far less common, PPMS can affect other parts of the central nervous system such as the brain stem (situated between the brain and spinal cord) and the cerebrum (the main body of the brain). Symptoms are seen in only around one percent of people with PPMS but may include:

  • Problems with swallowing (dysphagia)
  • Dizziness, vomiting, or nausea
  • Rapid, involuntary movements of the eyes (nystagmus)
  • Vision impairment or loss
  • Impaired cognitive function, including loss of memory, attention span, verbal acuity, or spatial reasoning

A Word From Verywell

Until recently, there were no drugs available to treat PPMS. Traditional disease-modifying drugs, like Rebif and Copaxone, work mainly by reducing inflammation associated with RRMS but have proven ineffective in treating the type of nerve degeneration seen in PPMS.

Luckily, things have changed. We now have a drug known as Ocrevus (ocrelizumab) able to treat PPMS as well as relapsing forms of the disease. Approved by the U.S. Food and Drug Administration (FDA) in March 2017, Ocrevus is considered a huge game changer and will likely improve the lives of those living with this uncommon form of multiple sclerosis.

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Article Sources
  • Ohrbach, R.; Zhao, A.; Wang, Y. et al. "Comparison of Disease Activity in SPMS and PPMS in the Context of Multicenter Clinical Trials.” PLoS One. 2012; DOI 10.1371/journal.pone.0045409.
  • U.S. Food and Drug Administration. "Ocrevus (ocrelizumab) Injection." Silver Spring, Maryland; March 28, 2017.