Sleep-related movement disorders (or SRMD for short) are characterized by simple, unintentional and often stereotyped movements during sleep. They’re especially common during sleep-wake transitions. These conditions are typically fairly benign, but they can be quite hard to diagnose accurately and treat. Some sleep-related movement disorders can be quite problematic in the long run, such as nighttime teeth grinding, a disorder that can damage the patient’s teeth and jaw. As a consequence, they’re often a source of considerable stress to parents whose children are experiencing these issues. Starting treatment is, therefore, a top priority, even if the condition is not currently causing any harm.
In this article, we will look at several sleep-related movement disorders to find out their potential risks and consequences, as well as how they’re normally treated. While the best idea is almost always to consult a doctor when dealing with these disorders, knowing the symptoms and causes yourself can help you understand their recommendations and also get some peace of mind, knowing that treatment options exist and the patient is less likely to suffer any long-term consequences. So let’s begin.
A General Overview of Sleep-Related Movement Disorders
The causes and contributing factors vary from case to case, although there is a consensus on how we can identify various sleep-related movement disorders. In most cases, a direct connection can be made between these disorders and the patient’s age, medical history or any medications they may be using at the time. For example, bruxism (also known as nighttime teeth grinding) primarily affects kids around age 6 or younger. After age 6, it subsides in the vast majority of cases. On the other side of the age spectrum, we have rapid eye movement (REM) sleep behavior disorder, affecting people older than 50.
Here’s the thing, however. Most if not all other sleeping disorders drastically increase the risk of becoming afflicted by a sleep-related movement disorder. Even if the original disorder isn’t the direct cause, the medication you take to fight against it could have nasty side-effects, including SRMD. Even medicine used to deal with depression, like SSRIs (selective serotonin reuptake inhibitors), can contribute to the risk. Other potential causes or contributors include heavy caffeine intake and stress.
As a consequence, the diagnosis process can get complicated. The doctors will want to know the patient’s full medical history and every bit of information about daily habits that could lead to increased SRMD risk. The most accurate way to find the causes is through a combination of the patient’s medical history and a detailed polysomnography procedure. It involves spending a night at the sleep lab, but the benefits are worth every second (and penny) invested.
Sleep-Related Movement Disorder List
We’ve covered the basics, but there aren’t many similarities between these conditions. It’s important to look at each one individually to get an idea of how you can solve your problem. In this article, the focus will be on the most common conditions, and we will cover their potential causes, risks and how they’re treated.
This condition is commonly known as nighttime teeth grinding. A distinction is usually made between child and adult bruxism. Around 30% of children aged 6 or under showcase this behavior. By the age of 13, this problem clears itself up in over 50 percent of cases. Once they reach adulthood, that percentage grows to around 90%. Think of it like bedwetting or night terrors – just a part of growing up for some children. Obviously, this doesn’t mean you shouldn’t take measures against it – regular dental check-ups are an excellent way to keep your child’s teeth safe from chipping or deformities. One of the main causes of nocturnal teeth grinding among children is the discomfort that comes with teething (the process where your child grows their teeth).
Adult bruxism is a different story. The main problem you run into with bruxism is that doctors don’t know for sure what causes it. Possible causes and contributing factors include stress, anxiety, genetics, and other sleep disorders (especially obstructive sleep apnea and rapid eye movement behavior disorder). Anxiety is the main potential cause, as 70% of adult bruxism patients give subjective reports that focus around it. Much like most sleep-related movement disorders, high caffeine intake or an alcohol or tobacco habit increases the risk of bruxism developing.
Unfortunately, there is no “cure” for nighttime teeth grinding. The best you can hope for is a set of methods that help neutralize or weaken the symptoms, so you or your loved one can sleep without worries. Before you seek out dental device or something similar, work on your sleeping habits and overall lifestyle. For example:
- Do exercises and activities that help you reduce stress, such as meditation, yoga or breathing exercises. Visit a sauna if you have the time or money. The more relaxed you feel in your day-to-day life, the less impactful bruxism symptoms can be
- Keep your jaw relaxed through massage, or by avoiding hard-to-chew food items and chewing gum. These foods put more strain on your jaw than usual which can cause or amplify the symptoms of bruxism.
- Remove or reduce the amount of alcohol, nicotine, and caffeine. This is much easier said than done, but these habits are a strong contributing factor for this disorder.
If you try these methods, and you still have to deal with unpleasant symptoms (such as jaw pain, changes in tooth shape, tooth pain, chipped teeth), it’s time to seek professional help. Luckily, dentists have a very reliable solution. They will take an imprint of your teeth and jaw, and create a custom-made protective set of jaw guards. These not only protect your teeth from the potential damage sustained through grinding, but they also reduce the noise, helping anyone else in the room sleep peacefully.
Nocturnal Leg Cramps
Nocturnal leg cramps are the name we use for a sudden calf muscle tightening during the night. This disorder is particularly common among pregnant women, but anyone can experience it. The probability of experiencing nocturnal leg cramps increases with age, as people above the age of 50 deal with it the most. Much like bruxism, there isn’t one specific cause you want to look for. These cramps could happen as a result of medication side-effects or metabolic diseases (such as hypothyroidism). Another common potential cause is simple dehydration. Endurance athletes often suffer from cramps, as they can’t reliably rehydrate during their trials.
The most impactful consequence of this disorder is that your sleep schedule and sleep architecture can get ruined because you keep waking up in pain. As a result, the impact is widespread, affecting your immune system, putting you at risk of drowsy driving and making you irritable and exhausted overall.
Treatment options are pretty simple. Increase the amount of potassium in your diet, whether by changing the dishes you regularly make or by taking supplements. Pregnant women will want to add magnesium pills to this combination. Make time in your schedule for regular muscle stretches and general exercise. Not only will this approach help you with nocturnal leg cramps, but it will improve the amount of energy you have to work with daily, and bring other general health benefits. Make sure you drink a lot of water, to prevent the risk of dehydration-induced leg cramps.
Periodic Limb Movement Disorder
Periodic Limb Movement Disorder (PLMD) is a condition portrayed by repetitive and involuntary limb movements during sleep. Don’t mistake this disorder for hypnic jerks, as those only occur at sleep onset, whereas periodic limb movement disorder is exhibited during sleep. The other disorder this might get confused for is restless legs syndrome (RLS), but RLS is characterized by a strong urge to move the legs due to a prickly sensation. While PLMD primarily causes legs, toes, and ankles to move, arms can be involved as well.
Because these limb movements happen during sleep and are completely involuntary, most people who suffer from this condition are unaware of it. However, if you’ve been dealing with this disorder for a while, you may notice fragmented sleep or daytime fatigue, or full-blown insomnia in the worst case scenario. An environmental hint you can pick up on is the position of your blanket and nearby items after you wake up. Your leg jerking can displace these things and tip you off that something is wrong.
PLMD affects roughly 4% of all adults. The probability is much higher for older adults (above age 65), at around 30%. This disorder often comes packaged in with another sleep disorder (usually restless legs syndrome, obstructive sleep apnea or narcolepsy), and can even be linked to other chronic conditions, such as diabetes or anemia. Unfortunately, we have not confirmed any guaranteed causes for periodic limb movement disorder, although there are solid theories. Genetic factors and iron deficiency are commonly linked to PLMD, as are a variety of genetic quirks. Because this disorder often comes bundled in with another condition, that condition is often considered the underlying cause, although not all of our research backs this up. The main methods of diagnosis involve a detailed analysis of the patient’s medical history and a full polysomnographic observation. Blood tests are often done to check the iron levels and similar values.
There is no real cure for periodic limb movement disorder, but there are measures you can take to alleviate some of the symptoms. While proper medication like gabapentin or dopamine agonists are necessary for the most severe cases (ones where the patient’s entire sleep rhythm is ruined by this condition), most people can resort to simple lifestyle alterations. A leg massage or a hot bath before bed can help out a lot, as can light exercise like quick walks. As is the case with most sleep disorders, you should avoid alcohol like the plague, and minimize your daily caffeine intake. If you take antidepressants, consult your doctor to make sure that your medication isn’t contributing to PLMD.
Everyone has experienced hypnic jerks (also known as sleep starts) in their life. Right as you’re about to fall asleep, a part of your body may suddenly jerk violently and startle you back into an alert state. Sometimes, many of these jerks can happen, one after another, for some time. Their intensity and frequency may vary, but it can get bad enough to cause people to be afraid to fall asleep. Most people rarely experience hypnic jerks, which is why it’s often not looked at as a disorder (despite being one). Children are the most susceptible, as sleep starts occur for them the most.
Contributing factors can vary from person to person, but they don’t stray too far away from the core offenders we’ve talked about already. Stimulants such as caffeine are a common contributing factor to almost if not every sleep-related movement disorder, as are things like iron deficiency. If you do intense exercise before bed, it increases the risk of hypnic jerks occurring. Stress is another well-known contributor, as are antidepressants (and their nasty side-effects).
Because of their relatively benign nature and commonplace occurrence, sleep starts are rarely treated properly. However, if a person’s sleep schedule and daily life are at serious risk from this condition, there are mostly reliable methods available. Iron supplements solve one of the most common problems in patients dealing with sleep-related movement disorders, while regular leg exercises (not right before bed) can lower jerk frequency and intensity. If the patient needs even more help, dopamine agonists are used, much like with RLS. Keep in mind that pregnant women should not be given dopamine agonists under any circumstances.
Co-founder of Counting Sheep and Sleepaholic