Like other disease forms, primary progressive multiple sclerosis (PPMS) is not itself fatal, though it may increase the risk of certain life-threatening complications such as pneumonia. The average lifespan for people with multiple sclerosis (MS) is about five to 10 years shorter than that of the general population, though this gap continues to narrow as MS care improves. Of note, the time from disease onset to death is generally shorter in PPMS than in relapsing disease forms — but because PPMS also usually manifests later in life, overall life expectancy is similar in all MS types.
The gradual accumulation of neurological symptoms that characterizes primary progressive multiple sclerosis (PPMS) can cause substantial difficulties in day-to-day life. Some activities may become difficult or impossible to do independently. Without treatment, it takes about a decade on average for someone with PPMS to require an aid such as a cane or crutch to walk short distances, but disease-modifying treatment can slow disability progression.
Most people with multiple sclerosis (MS) initially experience a relapsing-remitting disease course that is characterized by periods of remission where symptoms do not worsen over time. By contrast, in primary progressive MS (PPMS) symptoms gradually worsen over time from disease onset. Consequently, symptoms tend to accumulate more rapidly in PPMS than in other disease forms.
Because disabling symptoms tend to accumulate more quickly in primary progressive multiple sclerosis (PPMS) than in relapsing types of the disorder, people with PPMS are generally more likely than those with other disease forms to rely on wheelchairs and other assistive devices to improve mobility and get around in day-to-day life. But in clinical trials, the median time from disease onset to requiring a wheelchair was nearly two decades for people with PPMS taking Ocrevus — the only disease-modifying treatment approved in the U.S. for this disease type — which represents a seven-year delay in the need for a wheelchair compared with treatment with a placebo.
Although primary progressive multiple sclerosis (PPMS) is characterized by a gradual worsening of symptoms without relapse activity, some patients may experience disease relapses, in which new inflammation in the nervous system causes symptoms to suddenly worsen and then ease. However, by definition, people with PPMS do not experience periods of remission where symptoms remain stable for long periods of time between relapses.