Periodic Limb Movement Disorder (PLMD)

Not long ago I read that 80% of people with restless leg syndrome also have Periodic Limb Movement Disorder (PLMD). I did not know that. I myself belong to the minority of 20% that is not affected by this.

PLMD strikes me as an extremely unpleasant condition. Only restless legs would be disruptive enough for your night’s sleep. With PLMD you get an additional sleep disorder. I also read that over a third of the population above the age of 60 suffers from PLMD or RLS!

I would therefore like to devote a blog to this topic to list some facts. I do this on the basis of the following questions:

1. What is PLMD?
2. What are causes and effects?
3. Can you do something about it?

What is PLMD

Periodic Limb Movement Disorder is a sleep disorder and a movement disorder. PLMD is the only movement disorder that occurs while sleeping. About 4% of the population suffers from PLMD. It is more common in women than in men. Older people are more affected than young people.

The symptoms of PLMD are violent, jerky movements. This can occur every 20 to 40 seconds and up to a hundred times per hour. Each movement takes half to five seconds. Usually it is the legs that move during sleep. They are often typically rhythmic movements. In some patients the arms make sudden bending and stretching movements.

The movements are involuntary and uncontrolled. With every movement they get someone out of their (deep) sleep. The person in question usually does not experience this consciously, but does not wake up rested in the morning. PLMD often occurs in conjunction with restless leg syndrome.

The condition can also be associated with other illnesses such as:

• Parkinson’s disease
• Huntington’s disease
• Some forms of ADHD
• Narcolepsy
• Sleep apnea

Causes and consequences

The exact cause of periodically moving limbs is unknown.

It is suspected that it lies in the brain or in the spinal cord. Just as with restless legs, a lack of dopamine is thought to be a possible cause. This substance plays a role in automatic movements. In this case it is primary PLMD.

A shortage of iron, heredity or (side effects of) antidepressants can also be of influence. In that case you call it secondary PLMD.

Primary PLMD is often chronic. Symptoms can sometimes go away for a while before they return. Secondary PLMD is usually remedied when the underlying problem is addressed. However, no cause is found in most patients with PLMD.

PLMD, like restless leg syndrome, is a sleep disorder and has associated consequences:

• Drowsiness and fatigue
• Difficulty concentrating
• Leg pain upon waking up
• Not much energy during the day
• Memory problems
• Less productive at work
• Risk of depression
• Short attention span

What can you do

There are different types of medications for PLMD. As with restless legs, a doctor only prescribes these when the complaints are severe and someone no longer functions properly due to daytime fatigue.

Some of these drugs cause a higher level of dopamine in the brain. This reduces leg movements and improves sleep.

Lifestyle adjustments are another option. Also in this respect there is a strong similarity with restless legs. In part, you have to think about optimizing your sleeping conditions. You can read more about this in my blog about bad sleep.

Additional measures are:

• Sufficient (mild) exercise
• No caffeine
• No alcohol
• No smoking

Some patients seek refuge in the alternative circuit. Examples include massages, yoga, acupuncture, manual therapy or podiatry.