What Is Progressive Primary MS? Multiple Sclerosis

Depending on the severity and progression of the disease, MS is classified into four types:

• Clinically isolated syndrome (CIS): First episode of what could potentially be MS. It lasts at least 24 hours.
• Relapsing-remitting MS (RRMS): Characterized by clearly defined attacks of new or increasing neurologic symptoms (relapses), followed by periods of partial or complete recovery (remissions).
• Secondary progressive MS (SPMS): Starts as RRMS, but over the years the relapses are more frequent and get worse symptomatically.
• Primary progressive MS (PPMS): PPMS is a subtype of MS with the worst outcome, no symptom-free period, and more severe disability compared to other types.

PPMS can be further classified into the following:

• Active PPMS: An occasional relapse or evidence of new lesions in magnetic resonance imaging (MRI) over a specified period.
• Not active PPMS: Symptoms are present, but the disease is stable.
• PPMS with progression: Evidence of disability worsens over time, with or without a relapse or new MRI activity.
• PPMS without progression: Disability does not worsen, irrespective of MRI findings.

Irrespective of the type, MS affects the brain and the spinal cord. It has immune-mediated pathogenesis, which is triggered by genetic predisposition and poorly understood environmental factors. Viral infections, especially Epstein-Barr virus infection, may have a role in the development of MS.

The autoimmune reaction causes extensive demyelination of the neurons (destruction of the insulating sheath, called the myelin sheath, that covers the neurons), causing severe neuronal damage and swelling:

• People with PPMS tend to have more lesions in the spinal cord than in the brain compared to the other MS subtypes as confirmed by the MRI.
• Unlike other forms of MS, which affect women more, PPMS affects men and women equally.
• The average age of onset is approximately 10 years later in PPMS than in relapsing MS.

Primary progressive MS is diagnosed based on clinical progression, magnetic resonance imaging, optical coherence tomography, and cerebrospinal fluid examination.

The criteria for diagnosing PPMS are at least one year of disease progression (worsening of neurological function without remission) and two of the following:

• Type of lesion in the brain that is recognized by experts as being typical of multiple sclerosis (MS)
• Two or more lesions of a similar type in the spinal cord
• Evidence in the spinal fluid of oligoclonal band or an elevated immunoglobulin G index

Primary progressive multiple sclerosis (PPMS) is typically most difficult to manage. Because the disability is often the result of neuronal destruction and scarring (instead of just inflammation), symptoms may be difficult to manage, and most drugs are not as effective. Treatment options may include the following:

• The FDA has approved ocrelizumab, a recombinant human anti-CD20 monoclonal antibody for the treatment of adult patients with PPMS.
• Oral fingolimod may help slow down the disease progression in some individuals with PPMS.
• Glatiramer acetate, interferons, and rituximab have been used in various clinical trials with limited success.
• Bolus intravenous glucocorticoids, typically 1000 mg of methylprednisolone, have been used to treat acute PPMS episodes alone or in combination with other immunomodulatory or immunosuppressive medications with the aim of pain relief.
• Oral or subcutaneous methotrexate, 7.5 to 20 mg per week, with or without monthly glucocorticoid pulses, has been used to treat patients with progressive forms of MS with varying success rates.
• Rehabilitation and physiotherapy are cornerstones of PPMS because they help prevent muscle stiffness and pain.

There is no cure for multiple sclerosis (MS), and the treatment approach often depends on the symptoms, their frequency, and what suits the patient the best. 

Out of all the MS subtypes, primary progressive multiple sclerosis (PPMS) has the worst prognosis. Most people start to have symptoms at about the age of 50 or older (about 10 years later than is typical of relapsing forms of MS).

Many people with PPMS can walk years after a diagnosis, but usually, patients tend to get worse over time. Thinking, memory, and intellect are relatively spared with PPMS, but bowel, bladder, and sexual problems may be present.

In general, those with MS live 7-8 years less than the average population. Seeking treatment and adhering to physiotherapy may improve the disease outcome in many cases.