How Periodic Limb Movement Affects Everyone (Even the Cat)

A lot of people with restless legs syndrome (RLS) also have periodic limb movement (PLM), about 80 percent. Although PLM can happen at any age, the chance of having it increases with age.^1,2

Some people think that PLM and RLS are the same things. There is, however, a slight difference between them.

How are restless legs and periodic limb movements different?

RLS is the feeling that you want to move; everyone gives a different explanation of the feeling. Some say that it’s like insects on your legs. Some say it’s like soda in your veins. For me, it’s like my muscles cramp up really tight, like a strong muscle pain.

PLM is when the limbs are moving in an uncontrollable, shaking way. This can hurt really bad. I have both RLS and PLM and when my PLM is bad, especially during the night, I wake up feeling 90 years old. My whole body hurts and during days like this, I try to keep calm.

The real difference between PLM and RLS is that RLS is the urge to move your legs and PLM is the actual limb movement itself.

How is PLM diagnosed?

The diagnosis and the treatment for PLM are the same as for RLS.² My specialist, a neurologist, asked me a lot of questions, did some blood tests to see if there was anything else, and asked to make a video of the movements. After the diagnosis, he gave me medication that worked well for me.

What do periodic limb movements feel like?

The movements of PLM can be really strong. My boyfriend always tries to help me, but when the PLM is really bad, even he cannot stop my arms and legs from moving and he is a big, strong guy. When I notice my RLS is kicking in, most of the time PLM is next.

So I try to get into a situation where I don’t hurt myself or someone else with those strong movements. Sitting on the couch, away from the wall, so I only hit the couch and not the wall. Unfortunately, one time this went a little bit wrong. I was sitting on the couch with one of our cats on my legs. That was during a period when my RLS was not that bad, but my PLM was. So I didn’t notice that my leg would start kicking, but it did.

My beautiful, big, red cat was thrown across the room and landed a couple of meters further. The poor thing didn’t know what he did wrong. This shows how strong those movements are because our cat is around 5kg/10pounds. PLM can be a complete workout.

I am not always aware of PLMs

PLM, just like RLS, can happen when you’re awake and when you’re sleeping. Both can wake you up, but with PLM this is not always the case. Sometimes the arms and legs are moving but the person doesn’t know that.

Unfortunately, the person sleeping in the same bed does know and it can happen that someone is kicking someone else out of the bed, literally. So RLS and PLM are not only affecting the life of the person with the disorder, but also the people close to them.