A common Sleep-related movement disorder is Restless Legs Syndrome (RLS), also known as Willis-Ekbom Disease.
This is a sleep disorder that is characterized by an overwhelming urge to move the legs when at rest. The urge to move the legs is usually, but not always, accompanied by unpleasant sensations in the legs, such as pins and needles, or a “crawling” sensation under the skin. RLS symptoms occur during inactivity and they are temporarily relieved by movement or pressure. Symptoms of RLS are most severe in the evening and night time hours and can profoundly disrupt a patient's sleep and daily life. Some patients will kick their legs in their sleep (“periodic limb movements” in sleep, PLM’s).
Restless legs symptoms can be due to some medications and lifestyle factors. Low iron levels can worsen symptoms. It is readily recognised with a careful medical history and treatment is often prescribed when the symptoms interfere with sleep, especially if the RLS symptoms stop people falling sleep (contributing to sleep initiation insomnia).
Sleep-related bruxism or teeth grinding is another common movement disorder in sleep. This may first be evident to dentists who notice teeth damage from repeated night time teeth grinding. At times patients can present with jaw pain relating to jaw clenching overnight. Sleep-related bruxism can disturb sleep quality and severely damage teeth (e.g. teeth cracking). There are many causes, and in some instances breathing disturbances at night time (such as obstructive sleep apnoea) may be the main cause. Diagnosis of this cause requires a sleep study and treatment is then directed to opening the airway at night time to reverse the cause, rather than simply protecting the teeth from continued damage with an occlusive splint. Dentists and Sleep Physicians will usually work together to diagnose and treat sleep-related bruxism.