MMN - How is Multifocal Motor Neuropathy Treated?

You join us for the fourth in our weekly blogs dedicated to taking an accessible look at Multifocal Motor Neuropathy - or MMN. In previous editions, we've looked at what MMN is, the common MMN symptoms, and how you might expect MMN to be diagnosed.

So what happens when someone finally gets a diagnosis of MMN? What does treatment look like? Can it be treated? Can it be cured?

Let's start with - can it be cured? The short answer is, no. There is no current cure for MMN at the time of writing. While the condition itself should not impact someone's life expectancy, it will still be with them for their entire life.

That doesn't mean treatment to make that life comfortable doesn't exist though. There are treatments available to help reduce and reverse symptoms, improve independence, and restore some of the strength/dexterity that has been lost.

The most medically significant of these treatments is called IVIg - or intravenous immunoglobulin. If you've been following Inflammatory Neuropathies UK for a while, or you're living with an Inflammatory Neuropathy, you likely already know all about IVIg, but for those new to this world, let's take a look at what our community sometimes calls, "liquid gold."

(before we begin, it's important to remember that everyone's experience will vary depending on where and how MMN impacts you, your age, general health, pre-existing conditions, and more. This blog covers the average MMN experience)

What is IVIg? 

And what is Plasma?

IVIg stands for intravenous immunoglobulin.

IVIg is a treatment made from donated human plasma. Plasma is the liquid part of your blood. 

Your blood is comprised of approximately:

• 55% liquid plasma

• 44% red blood cells

• 1% white blood cells and platelets

Plasma carries blood cells, proteins, nutrients, and salts throughout your body. It also carries waste products to your kidneys and liver. 

Among the proteins in plasma are antibodies. These recognise and fight infections such as viruses and bacteria. They are a vital part of your immune system. 

However, in Inflammatory Neuropathies like MMN, these antibodies can go wrong. Instead of protecting you and fighting off infections, they mistakenly recognise your nerves as a threat and launch an attack.

In MMN this attack can be subdued temporarily by IVIg.

IVIg is made up of healthy antibodies from donor blood and plasma. It floods the body with a supply of these antibodies which helps to rebalance the immune system, reduce inflammation, and interrupt the harmful immune attack on your nerves.

In the case of Guillain–Barré Syndrome, one of the other Inflammatory Neuropathies we support, this can end the attack, and allow for the person with GBS to begin to recover.

In the case of MMN, this impact is temporary but it with frequent treatments, the condition can be managed.

We'll look into this in more detail later in this blog.

 How is IVIg given? 

You'll visit a hospital or clinic close to you that can administer IVIg. You'll sit on a chair or a raised bed and a drip will be inserted into your arm (or another appropriate site). Over a course of several hours, the IVIg will be infused into your bloodstream. Depending on your dose, this can be one session, or may take a day or two. Your Doctors and Nurses will discuss that with you. 

Most people can sit fairly comfortably during the session, you shouldn't feel pain or discomfort. So do bring something to entertain you - a book, your phone or laptop, a pair of headphones, or a friend to chat to. Your medical team will keep an eye on you throughout, so you may even be allowed to doze off for a while if you prefer. 

It's worth taking a trip to the toilet first, usually the machine can be paused or you may have a drip on wheels - but it just makes life a little easier for everyone.

 How often will I get IVIg, and what dose? 

Picture a child's drawing of the sea, there's waves that go up and down sharply.

MMN, like CIDP and many other Inflammatory Neuropathies, has its symptoms come in:

• 'dips' - the bottom of the wave: minimal symptoms

• 'spikes' - the top of the wave: symptoms worsening.

The first time you receive treatment, you'll likely be in a spike phase. 

Once you receive your IVIg, you can expect to feel a degree of improved motor function. Some may only experience slight improvement, others may feel a significant improvement across strength, grip, and movement. In some rare cases you may even feel like you have no symptoms at all. 

You'll now be in a dip phase. You're feeling stronger. You're feeling less MMN symptoms. 

Did you know: following his IVIg, New Zealand based Clive Phillips was able to cycle 3,200km around France to raise awareness of MMN? Learn more here

Slowly, perhaps over 2-5 weeks (everyone is a little different), you'll start to feel weaker as the MMN symptoms return.

You're now beginning to come out of a dip and into a spike. At this stage you'll be given treatment again. Treatment given shortly after symptoms begin to appear is always more effective than letting symptoms set in fully. 

Your care team will work out the pattern/frequency of treatment that is right for you. In an ideal world, treatment timing would smooth those spikes and dips into a steady, balanced line. In reality, that isn’t always possible - but careful planning between you and your care team can help reduce the severity of those waves as much as possible.

You may find your dose changes over the weeks, months, and years ahead. This is a normal part of the treatment process and can stem from how your body responded to the previous dose, body weight fluctuations, and even controlled experiments by the care team to see if you can have a smaller dose, or longer gaps between.

While it can be frustrating, it is usually a sign that your care team is actively reviewing and refining your treatment to give you the best possible control of your symptoms.

It is also important to remember that your condition itself may change over time.

Some people experience periods of greater stability, while others may go through phases where the immune system becomes more active. Treatment plans evolve to reflect those changes.

It's important to remember: These adjustments are not setbacks. They are simply part of a careful fine-tuning process to allow you the best quality of life possible.

If you are ever unsure why your dose has been altered, ask. Understanding the reasoning behind adjustments can make the process feel more collaborative and less unsettling.

 Can I get IVIg at home? 

In some cases, you may be able to receive your immunoglobulin treatment at home. This is usually done by SCIg rather than IVIg. SCIg is Subcutaneous Immunoglobulin and differs from IVIg in that it is given via an injection under the skin (subcutaneous) rather than into a vein.

For many it is more convenient as it removes the need for travel and frequent hospital visits. However, for various reasons - including suitability, cost, training, and availability - it is not often offered as a solution.

You can ask your clinician about SCIg if you think it will have a significant impact on your quality of life, but there is unfortunately no guarantee you will receive it.

Can my veins handle IVIg forever?

Repeated IV access can impact your veins, particularly if you're receiving treatment frequently for a long time. Over time, some (but not all) may find their veins become harder to find, or narrow and scar. You might find you bruise more easily, or experience a little discomfort during the procedure.

To avoid this, your infusion team will likely rotate vein sites so they're not overwhelming the same spot. Good infusion practice will help keep your veins as healthy as possible for as long as possible.

If you're finding your infusion sites get irritated, your team may slow down infusion rates to lessen the stress in that area.

In some rare cases, they may look at inserting something called a long-term venous access device such as a port.

If your veins really are responding negatively to the treatment, they may also look at switching you to a different treatment including SCIg (see Can I get IVIg at home section above).

 What other treatments are there? 

IVIg is not a cure for MMN but currently no other therapy has proven to be widely effective. In a limited number of patients a cancer chemotherapy drug is temporarily effective. However, its use is limited by the toxic side-effects and risks that accrue with chronic use.

Other immunosuppressive treatments such as corticosteroids and plasma exchange are ineffective and can actually make the condition worse.

Many investigators around the world are working towards a better understanding of MMN, we hope any research we fund can help this journey.