Difference between SPMS & PPMS

Hi more knowledgeable ones. So it’s never really made clear on the internet but what is the difference? Do you go from SPMS to eventually PPMS or are you just diagnosed with PPMS from onset if you show no signs of remission? Thanks,

Hello Ralee

SP and PPMS come from completely different variants of MS.

The most common type of MS is relapsing remitting, or RRMS. It’s defined as such by the pattern of relapses (often confusingly called flares), followed by remission, either complete or partial. It’s the only type of MS that has for years had disease modifying therapies available ( DMTs or DMDs) designed to reduce relapses although this is gradually changing. Relapses often completely remit, but often there is only partial remission, so symptoms can become permanent.

Over time, RRMS may develop into secondary progressive, or SPMS. This is quite difficult to exactly pinpoint as there can be a very long time between relapses, leading people to think their MS has become progressive. It’s where the relapse and remission phase the disease stops and there is just general progression with no remission.

Many people on the RR/SP pattern of MS are also now being diagnosed as relapsing progressive. This is where relapses are still clearly present, but there is definite progression too.

Primary Progressive MS, aka PPMS, appears to be a completely different variant to the RR/SP type. In PP, there is no clear pattern of relapse and remission. It’s waves of activity don’t seem to remit, instead the disease is just progressive from the outset. Recently, a DMD has become available for relatively recently diagnosed PPMS: Ocrevus.

People, are typically labelled as RRMS from the outset in order that DMD’s can be prescribed. Given that it’s the most common variant, it seems a sensible way of starting treatment in the absence of a clear pattern of progression.

It’s often considered that RRMS is the least serious or least disabling variant of MS, but this isn’t necessarily the case. Relapses can be severe and leave quite disabling damage behind them. For example, optic neuritis can leave permanent damage to the optic nerve, thus eyesight. Relapse activity on the spine can leave permanent lesions or scars on the myelin that’s covers the nerves (supposedly to ‘protect’ the nerves, think of it as like electric cabling covered by plastic to protect the wires). This can leave serious disabling symptoms, lack of mobility, depleted perception or spasms and spasticity.

Whichever type of MS is diagnosed, it’s a cr@p disease and always a bugger to have to live with. The symptoms of all types are variable and unpredictable. The disease pattern and prognosis are impossible to predict from the outset. While there are people with all types of MS who are quite mildly affected by the disease, there are also people with all variants who are seriously disabled by it.


Thank you Sue, I was recently diagnosed and was curious what the differences were between those 2. Very informative answer and really helps strengthen my understanding of this horrible disease. Kind regards,

Yeh Sue, very clearly explained. Cheers! Bouds x