Understanding Rem Sleep Disorder: Do I Have It?

REM sleep behaviour disorder (RBD) is a condition in which people act out their dreams, often violently, and can cause injury to themselves or their bed partner. The symptoms of RBD can vary in severity, ranging from mild muscle twitches to jumping out of bed. It is a parasomnia, a sleep disorder that involves abnormal and undesirable physical events or experiences that disrupt sleep. RBD is relatively rare, affecting less than 1% of the population, and usually begins after the age of 50. If you think you may have RBD, it is important to consult a doctor, as it is often associated with other neurological conditions and can be treated with medication and lifestyle changes.

What are the symptoms of REM sleep behaviour disorder?

REM sleep behaviour disorder (RBD) is a sleep disorder where a person physically acts out their dreams while in the rapid eye movement (REM) stage of sleep. The symptoms can vary in severity and commonly include:

• Mild muscle twitches or limb movements
• Vocalisations, such as talking, shouting, or screaming
• Larger body movements, such as punching, kicking, jumping out of bed, or grabbing their bed partner

People with RBD are often unaware of their behaviours during sleep and may only find out by being told about their symptoms by a bed partner or roommate. Episodes can occur once or multiple times during the night, and the symptoms tend to worsen over time.

During an episode of RBD, a person may appear as if they are acting out a bad dream. For example, if they dream about being chased, they might jump out of bed and try to run away. These actions can potentially cause injury to themselves or their bed partner, so it is important to seek treatment and create a safe sleeping environment.

How is it diagnosed?

If you think you may have REM sleep behaviour disorder, it is important to consult a doctor or healthcare provider. They will ask you questions about your symptoms and medical history, and may also ask your bed partner or housemates about your sleeping behaviour.

Your doctor will then perform a physical and neurological exam, and may refer you to a sleep specialist or neurologist for more comprehensive testing. You may be asked to fill out the Epworth Sleepiness Scale, which helps determine how your sleep patterns are interfering with your daily life.

To receive a diagnosis of REM sleep behaviour disorder, you will undergo an in-lab video sleep study, or polysomnogram (PSG). Sleep studies are tests that record specific body functions during sleep, such as your breathing rate and airflow, brain wave activity, and muscle movements of your chin and upper extremities.

According to the International Classification of Sleep Disorders, a diagnosis of REM sleep behaviour disorder requires the following:

• Repeated episodes of sleep-related vocalisation and/or complex movement behaviours.
• Episodes occur during REM sleep, as confirmed by a sleep study or your clinical history.
• Episodes include sleep without atonia, as confirmed by polysomnography.
• The episodes are not attributed to another sleep or mental health disorder, side effects of medication, or substance abuse.

What causes it?

REM sleep behaviour disorder (RBD) is a parasomnia, a sleep disorder that involves unusual and undesirable physical events or experiences that disrupt your sleep. During RBD, people act out their dreams, which are often vivid and frightening. This can include physical movements and vocalisations during sleep, such as talking, shouting, screaming, punching, kicking, grabbing, and jumping out of bed.

There are two main types of RBD: isolated (idiopathic) and symptomatic (secondary). Isolated RBD occurs spontaneously without an underlying cause, while symptomatic RBD is due to an underlying cause. Up to 97% of people with isolated RBD will develop a neurodegenerative condition, such as Parkinson's disease, Lewy body dementia, or multiple system atrophy (MSA). These conditions are called alpha-synucleinopathies and are characterised by the abnormal accumulation of the alpha-synuclein protein in the brain.

The exact cause of RBD is not fully understood, but it is believed to be related to disruptions in certain neural pathways in the brain. During normal REM sleep, the body experiences temporary paralysis of most skeletal muscles, allowing us to dream safely. This temporary paralysis, known as muscle atonia or atonia, is controlled by certain cells in the pons region of the brainstem. In people with RBD, this temporary paralysis does not occur, enabling them to physically act out their dreams.

One theory suggests that lesions or damaged tissue in the pons region of the brainstem may be the cause of isolated RBD. This is supported by the strong association between isolated RBD and neurodegenerative disorders, as lesions in the pons are also associated with Parkinson's disease, Lewy body dementia, and MSA.

Symptomatic or secondary RBD can be caused by underlying conditions such as Type 1 narcolepsy, which is characterised by a lack of orexin, a brain chemical that regulates sleep, wakefulness, and appetite. The lack of orexin may fail to stabilise REM sleep, leading to RBD.

Additionally, certain medications, such as antidepressants, can induce RBD. Research suggests that imbalances in the neurotransmitters dopamine and serotonin, which are involved in REM sleep, may be responsible for drug-induced RBD.

Risk factors for developing RBD include being over 50 years old, having a neurological disorder, and using certain medications or antidepressants. While RBD can occur at any age, it most commonly affects people over 50, with an average onset age of 61.

How is it treated?

The main goal of treatment for REM sleep behaviour disorder (RBD) is to create a safe sleeping environment for the patient and their bed partner. This can involve certain strategies, medications, and lifestyle changes.

Safety Measures

• Removing sharp, glass, and heavy objects from the bedroom
• Placing pillows between the patient and surrounding structures, such as the headboard or a nightstand
• Placing a mattress on the floor next to the bed in case the patient falls out of bed, or using padded bedside rails
• Sleeping in a sleeping bag
• If the symptoms are severe, it may be safest for the bed partner to sleep in a separate room

Medication

If safety measures are not enough to prevent injury, a healthcare provider may prescribe medication to manage the symptoms. While there are no U.S. Food and Drug Administration (FDA)-approved medications specifically for RBD, studies have shown that melatonin, clonazepam, and pramipexole can reduce symptoms in some cases.

Melatonin is a hormone that is naturally produced by the pineal gland and is essential for regulating the sleep cycle. It is considered the first-line medication for treating RBD as it rarely causes side effects. Treatment usually begins with a baseline dose, which is then increased gradually until symptoms improve.

Clonazepam is a sedative. Researchers are unsure why it helps treat RBD, but most people with RBD who take a low dose of clonazepam before they sleep have few or no nightmares, vocalisations, or dream enactment behaviours. However, clonazepam can cause unpleasant side effects, so it is usually only prescribed if melatonin does not help.

Pramipexole is a dopamine agonist, primarily prescribed to treat Parkinson's disease and restless leg syndrome. Recent research shows that it can also help treat the symptoms of RBD. Researchers believe this medication works because RBD may be a dopaminergic deficiency disorder.

Lifestyle Changes

Making lifestyle changes to reduce or eliminate the use of certain alcohol or prescription drugs may be part of a person's treatment. These changes can be part of a larger set of steps to improve sleep hygiene, such as setting a consistent sleep schedule, which can normalise sleep and promote better sleep quality.

Who is at risk?

It is important to understand that anyone can develop a REM sleep behaviour disorder, but certain factors can increase the risk. While the exact causes are not fully understood, there are some clear patterns and trends that have been observed.

Age is a significant factor, with those over 50 years old being more prone to the disorder. This may be due to the natural changes in sleep patterns that occur as we age, with older adults often experiencing less REM sleep. Additionally, older individuals are more likely to be taking medications that can impact sleep and may have other underlying health conditions that contribute to sleep disturbances.

Men are more commonly affected by REM sleep behaviour disorder than women. This gender disparity is not fully understood, but it is believed that hormonal differences may play a role. The disorder often presents in middle-aged or older men, with symptoms sometimes appearing earlier in life but often being misdiagnosed or overlooked.

A family history of REM sleep behaviour disorder or other sleep disorders can also increase the risk. There is a strong genetic component to this disorder, and it is often seen running in families. If you have a parent or sibling with the disorder, your risk of developing it is likely higher. This may be due to shared genetic factors or environmental influences, or a combination of both.

Certain medical conditions are also associated with an increased risk of developing REM sleep behaviour disorder. These include neurological disorders such as Parkinson's disease, Alzheimer's, and Lewy body dementia. People with these conditions often experience sleep disturbances, and REM sleep behaviour disorder can be an early sign of these neurological issues.

Additionally, those with mental health disorders, such as PTSD, depression, or anxiety, may be more at risk. The relationship between mental health and sleep is complex, and further studies are needed to understand the specific reasons for this increased risk. However, addressing sleep issues is crucial for managing overall mental health.

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