Medically reviewed by
Dacelin St Martin, MD
Triple board-certified in Sleep Medicine,
Internal Medicine, and Pediatrics.
Many sleep-related, movement-causing disorders can make it difficult to get quality sleep. This classification starts with conditions exhibiting simple or minor movements (quick movements affecting only one body part) and delves into various complex behaviors.
Abnormal movements and behaviors can happen during sleep, wakefulness, or transitioning in and out of either state.
Keep reading to find out more about these sleep disorders, predisposing factors, symptoms, evaluation, differential diagnosis, and management.
Types of Sleep-Movement Disorders
Sleep-related movements, as classified by the International Classification of Sleep Disorders, are either simple or complex.
Simple movements are characterized by one single movement that affects a single part of the body and tend to occur between sleep and wakefulness.
Exploding Head Syndrome
People who have exploding head syndrome complain of “feeling” a loud and painless explosion inside their head when they’re just about to doze off or wake up. There is no actual movement in this case, and patients sometimes confuse the syndrome with headaches.
Hypnic jerks is a benign disorder that occurs at sleep onset and can be caused by excessive caffeine intake or sleep deprivation. It comes with a frightening feeling like you’re about to fall, which causes your whole body to jerk awake from sleep suddenly.
Sleep-Related Leg Cramps
You know you have sleep-related leg cramps if frequent sudden and painful muscle contractions in your thigh, foot, or calf disturb your sleep at night.
Bruxism or Teeth Grinding
Sleep bruxism causes your jaw to forcefully contract while you’re sleeping, which in turn makes you grind or clench your teeth intermittently throughout the night. This action’s primary consequences include tooth pain, morning headaches, and soreness in the face, jaw, or neck.
These conditions are characterized by benign involuntary jerks, during sleep onset, NREM sleep, and upon waking or soon after waking:
- Propriospinal – Jerks in the abdomen, neck, or trunk that occur during sleep onset can happen throughout the day.
- Epileptic – This is a type of seizure in children and adolescents upon waking or soon afterward.
- Benign Sleep (Infancy) – These are jerks that occur in babies during their first weeks of life, during the NREM stage. They are part of typical neurological development.
Periodic or Rhythmic Movements
Typically, periodic and rhythmic movements differ from simple movements in that they are more noticeable. They are characterized by leg and foot movements and can include the head and torso.
Hypnagogic Foot Tremor
You can easily tell hypnagogic foot tremors apart from other leg-related sleep disorders because they occur only in one foot. The affected foot undergoes a short rapid burst of movement that lasts about 250–1000 milliseconds. The movement typically occurs at sleep onset or during NREM sleep.
Periodic Limb Movement Disorder
Periodic Limb Movement Disorder is the most common sleep-related disorder. It often manifests as the repetitive movement of the legs and sometimes the arms during light NREM sleep. Each episode lasts between 0.5 to 10 seconds and repeats itself after 5 to 90 seconds.
Complex movements and parasomnias are characterized by bizarre behavior, perceptions, and movements during sleep but can be misunderstood as deliberate by others.
NREM Sleep disorders
NREM sleep-related parasomnias can be distinctly categorized:
- Disorders of arousal: sleep terrors, confusional arousals, and sleepwalking
- Sleep-related eating disorders
Disorders of Arousal
During one of these disorders (sleep terrors, confusional arousals, and sleepwalking), you’re caught between a state of deep sleep and wakefulness. Your mind is sleeping, but the neurotransmitters responsible for wakefulness are “awake” and working. You may become confused and talk, run, walk or shout; however, your recollection of the event may be minimal.
Like sleep arousal disorders, sleep-related eating disorders occur due to being stuck between NREM sleep and wakefulness. The condition is characterized by involuntary and recurrent binge eating during NREM sleep, with little to no memory of the event. You may find yourself unconsciously gorging on strange foods, like raw pasta or toxic food, like raw beef, if you have this syndrome.
REM Sleep Disorders
Sleep disorders associated with the rapid eye movement stage include REM sleep behavior disorder, recurrent sleep paralysis, and nightmares.
REM sleep behavior disorder (RBD)
RBD is a parasomnia that can cause you to re-enact violent and dramatic dream scenes during REM sleep.
Ideally, the body is in a state of paralysis at the REM sleep stage, but when RBD is present, you’ll be able to move your limbs or whole body even while asleep.
Behaviors usually exhibited in RBD range from mild limb movements to violent actions, such as kicking, punching, jumping out of bed, and yelling out expletives.
RBD is commonly seen in men from age 50 and above, but it can also affect women and younger people. Studies show that RBD can be a predictor of Parkinson’s disease, multiple system atrophy, and dementia with Lewy bodies.
A nightmare disorder is characterized by vivid, troubling dreams that cause fear, anxiety, and anger.
This parasomnia occurs more frequently during the second half of the sleep period during REM sleep.
Even though nightmares have no motor components and do not cause dream enactment, patients sometimes jerk awake or wake up screaming.
Sleep Paralysis (SP) occurs when the temporary paralysis of REM sleep encroaches into wakefulness, either upon waking or falling asleep.
You may feel completely awake; however, you’re unable to move your body, which leads to feelings of fear. You may hallucinate or feel pressure on your chest.
Sleep paralysis can sometimes be triggered by an irregular sleep-wake schedule or sleep deprivation. Other times, you may experience SP because it runs in your family.
Vocalization can occur on its own as a form of sleep talking, or it can occur during the disorders of arousal (sleep terrors or sleepwalking) and RBD.
Panic or Dissociative Events
Psychiatric symptoms of panic and dissociation can happen during sleep, as well as during the day. Often, this disorder is linked to trauma and mood disorders.
Parasomnia symptoms can be triggered or worsened by a lot of factors, some of which include:
- Emotional stress
- Mental health disorder
- Sleep deprivation
- Poor sleep hygiene
- Post-Traumatic Stress Disorder (PTSD)
- Drug or alcohol abuse before going to bed
- Circadian rhythm disturbances (caused by changes in work shift and jet lag)
Diagnosis of sleep-movement disorders can be based on a physical and neurological examination, symptoms, and test results.
The evaluation should include observations by loved ones, a detailed medical history, the family’s medical history, a list of medications, and a safety assessment.
Other areas and tools used for evaluation include:
- Polysomnogram, a test that involves monitoring your brain activities, eye movements, oxygen levels, heart rate, and breathing functions with a machine’s help, is commonly recommended.
- Diagnostic tests, including neuroimaging, to diagnose abnormal sleep movement and behaviors.
- Behaviors associated with RBD should be screened for Parkinson’s disease.
All abnormal movement disorders during sleep can be managed in either of these two ways:
- Identifying the triggers and eliminating or reducing them
- With medications
However, before you’re given any treatment, your doctor will ask you (and in some cases, your sleep partner) questions or carry out some tests. This approach determines your condition’s severity and frequency and finds out if underlying medical ailments are triggering your nocturnal movements.
If you’re diagnosed with simple sleep-related movements like hypnic jerks or any form of arousal disorders (e.g., sleepwalking, sleep terrors, etc.), you may not be given drugs. Your doctor will likely try to determine if inadequate sleep, insomnia, or other known triggers could be causing your sleep movements.
If you’re taking serotonergic antidepressants or short-acting hypnotic drugs, you may be advised to discontinue these medications as they are possible triggers.
Your doctor may ask you to make behavioral and lifestyle changes for the parasomnia and complex sleep-related movement disorders, depending on the disorder’s cause. You may also be treated with drugs.
It’s imperative to assess the symptoms for a correct diagnosis. It’s possible for comorbid sleep conditions, like obstructive sleep apnea (OSA), to exacerbate sleep-movement disorders.
Periodic limb movement disorder could be mistaken for a more serious condition called restless legs syndrome (RLS), resulting in excessive daytime sleepiness.
Narcolepsy can be the primary cause of sleeplessness, hallucinations, and sleep paralysis, making a comprehensive analysis imperative for neurological health.
Many factors contribute to an individual’s good physical and mental health, and adequate sleep ranks at the top of the list.
Parasomnias and other disorders that cause movement during sleep can make it hard for you to sleep well or get the amount of sleep your body needs.
When this happens, you may notice unusual tiredness, headaches, and sleepiness during the day. You may also become easily irritated and notice other adverse changes in your thoughts and emotions.
In cases like this, it’s essential you find and share your concerns with a sleep doctor. Moreover, since most sleep movement disorders are treatable, getting an accurate diagnosis would help your doctor provide the right treatment for you.
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