Periodic Limb Movement Disorder

Sleep disorders come in many forms, and one of the more unusual is periodic limb movement disorder, or PLMD. It is closely associated with the better-known restless leg syndrome (RLS). If you suffer from RLS, you have an 80% chance of also having PLMD.

While it can affect anyone at any age, the chances of you experiencing PLMD are much greater as you age. Just 2% of Australians aged under 30 experience it, but around 40% of over 65s. For instance. It affects men and women at similar rates and is often found in tandem with other sleep disorders. This is because lack of quality sleep is thought to be a contributing factor. If you have narcolepsy, sleep apnoea or other problems, you may also develop Periodic Limb Movement Disorder.

Because PLMD can affect you in several ways and is closely associated with some other sleep issues, it is often referred to as Periodic Limb Movements of Sleep (PLMS) today.

What is Periodic limb movement disorder?

PLMD is a sleep disorder that causes rapid twitching of the legs or arms during sleep. These movements can manifest as cramping or more violent jerking, and they can happen every few seconds for up to an hour.

The key aspect of PLMD to recognise is that it is a specific movement, repeated over and over again. Those repetitions can come every few seconds, usually somewhere between 5 seconds and a minute, and will be completely involuntary.

If you do suffer from periodic limb movement disorder, it may be something you never even notice, with micro-movements that are hard to perceive. This could be something as minor as your toes flexing or your foot straightening and will have no impact on your sleep patterns. If you have these symptoms, you may never know you’ve ever suffered from PLMD.

Photo by Angela Roma

However, it can be more impactful, with more violent kicking movements severe enough to disrupt your sleep and possibly wake your partner. In these cases, you will need help, but like most sleep disorders, the causes of PLMD are not completely understood.

What are the factors that make someone susceptible to this affliction?

While exact PLMD causes remain unknown, there is enough research and data to understand what many sufferers have in common. The biggest connection is with restless leg syndrome, with 80% of those who have periodic limb movement disorder also being afflicted with RLS. However, if you have sleep disorders of any kind, that can increase the chance of having PLSD. This includes a variety of issues that affect REM sleep and other problems such as narcolepsy.

Recent studies have also shown that low iron levels in the brain are common. This is also a symptom of a number of nervous system issues, and it may mean you are susceptible to periodic limb movement disorder.

In addition to the sleep issues, many conditions can make it more likely you develop PLMD, including:

• Diabetes
• Anaemia
• Taking some medications such as antidepressants or neuroleptics
• Spinal Cord damage
• Pregnancy

Studies continue to look for more solid connections between specific medical conditions and PLMD as part of a growing understanding of the condition. However, if you do have any of these and are in the older age brackets, your risk of showing symptoms increases.

What are some of the symptoms?

The involuntary movement that PLMD causes is the key symptom; however, you will not always notice it exists. This is not as much of a problem as you may think. If you are having episodes that feature very small movements that do not disturb your sleep, then there is nothing to worry about. These can be something like a twitching toe or straightening and bending the foot, but if you have more severe episodes, then they can be an issue.

You may find that you wake up with your legs moving rapidly and quite violently, enough to wake a partner, too. In some cases, your partner may complain of being kicked, and if it is bad enough to disturb your sleep, then it is a problem.

No matter how severe or not the movement is, the key symptom of PLMD is that it is repetitive movement, usually repeated every few seconds, and can last for as much as an hour. You may have bouts several nights in a row and sometimes not at all. It will usually happen not long after you have gone to sleep, and like so many sleep disorders, there is no formal cure.

Are there any treatments for Periodic limb movement disorder?

Unfortunately, as the exact cause of PLMD remains unknown, there are no specific PLMD treatments that can resolve the issue. Instead, some approaches lower the impact and help manage the condition. The most common approach to PLMD treatment is to improve sleep quality and duration.

This can include several lifestyle changes, such as reducing your caffeine intake, stopping smoking, and avoiding alcohol, but also focusing on other conditions. Dealing with iron deficiency, sleep disorders, and other conditions connected to developing PLMD can help you manage the problem.

Conclusion

If you find yourself with uncontrollable movements when sleeping, either enough to wake yourself or disturb your partner, it could be PMLD. Diagnosis usually involves a review of sleep history and blood tests, but as we are still unsure of PMLD causes, there is no formal treatment you can just put into place.

If you are older and already have some sort of sleep disorder, you do have a relatively high risk of developing PLMD, and that is even higher if your parents have suffered from it too. However, it is manageable, and you can live life normally even with Periodic Limb Movement Disorder.

Featured post photo by Marie-Michèle Bouchard on Unsplash