The Dark Side Of Rem Sleep Disorder: Can It Kill?

REM sleep behaviour disorder (RBD) is a sleep disorder in which a person physically acts out their dreams while being unaware of their actions. The movements involved in RBD can cause injury to the person or their bed partner, especially if they are acting out a violent nightmare. This raises the question: can someone with RBD kill another person?

What are the symptoms of REM sleep behaviour disorder?

REM sleep behaviour disorder (RBD) is characterised by a person physically acting out their dreams during the rapid eye movement (REM) stage of sleep. The symptoms can vary in severity, but generally, a person with RBD will exhibit the following behaviours:

• Mild muscle twitches or limb movements
• Vocalisations, such as talking, shouting, or screaming—often using vulgar language
• More pronounced physical movements, such as punching, kicking, grabbing, jumping or falling out of bed, or flailing their arms
• In some cases, a person with RBD may even hurt themselves or their bed partner

The dreams associated with RBD are often vivid, frightening, and intense, and the person acting them out is unaware of their behaviour during sleep. The person can usually be awoken relatively easily during an episode and will typically be alert and coherent upon waking, with the ability to recall the content of the dream.

Episodes of RBD can occur once or multiple times during the night, and a person may experience them a few times a year or every night. They can develop suddenly or gradually, but symptoms typically worsen over time.

What causes REM sleep behaviour disorder?

REM sleep behaviour disorder (RBD) is a sleep disorder in which the individual physically acts out their dreams while being unaware of their actions. This occurs due to the absence of temporary paralysis during the REM stage of sleep, which usually renders the body immobile while the brain remains active. While the exact cause of RBD is unknown, it is often associated with other neurological conditions and the use of certain medications.

There are two main types of RBD: isolated (idiopathic) and symptomatic (secondary). Isolated RBD occurs spontaneously without an underlying cause, while symptomatic RBD is triggered by an underlying condition or external factor.

Isolated RBD is linked to potential issues in the brainstem, specifically the pons, which controls muscle paralysis during REM sleep. Lesions in this area are associated with Parkinson's disease, Lewy body dementia, and multiple system atrophy (MSA). Research indicates that 97% of individuals with isolated RBD will develop one of these conditions within 14 years of their RBD diagnosis.

Symptomatic RBD can be caused by Type 1 narcolepsy, which is characterised by a lack of orexin, a brain chemical that regulates sleep, wakefulness, and appetite. The absence of orexin can lead to unstable REM sleep, resulting in RBD.

Additionally, certain antidepressants have been implicated in causing drug-induced RBD. This is attributed to imbalances in dopamine and serotonin, neurotransmitters that play a role in REM sleep regulation.

Other risk factors for developing RBD include being over 50 years old, having a neurological disorder, using certain medications or antidepressants, and substance use or withdrawal. While rare, RBD can also occur in children in higher-risk groups.

How is it treated?

Treatment for REM sleep behaviour disorder (RBD) is tailored to the individual. It can involve a combination of lifestyle changes, medication, and injury prevention techniques.

Lifestyle Changes

Because the use of certain drugs or alcohol can contribute to RBD, making lifestyle changes to reduce or eliminate their use 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, that normalise sleep and promote sleep quality.

Medication

Melatonin is the preferred, first-line medication for RBD. It usually has fewer side effects than other medication options but has similar efficacy. It is also a safer option for elderly individuals, individuals with dementia, fall risk, or those with sleep apnea. The dosage of melatonin one should take for RBD is different from when taking it to fall asleep, and one should consult a sleep physician.

The prescription drug clonazepam has proven effective in reducing symptoms for 50-80% of individuals with RBD. However, it can cause some side effects, including sleepiness, forgetfulness, and impaired balance in the morning. It can also contribute to or worsen sleep apnea.

If clonazepam is not effective, certain antidepressants may help to calm violent behaviour during sleep.

Injury Prevention Techniques

Establishing a safe sleep environment is one of the most important things someone with RBD can do. Recommendations for injury prevention may include:

• Removing sharp objects and weapons from the bedroom
• Placing padding on the floor around the bed
• Installing padded bed rails on the side of the bed
• Putting the mattress on the floor
• Moving furniture and clutter away from the bed
• Padding the corners of furniture in the bedroom
• Protecting bedroom windows
• Sleeping in a separate room or bed from their partner until symptoms are well treated

What are the risks of not treating it?

REM sleep behaviour disorder (RBD) is a parasomnia, or sleep disorder, that can cause those affected to physically and/or vocally act out their dreams, sometimes in violent ways. The risks of not treating RBD are significant and can be life-threatening.

Firstly, individuals with RBD are at risk of injuring themselves or their bed partners. The violent nature of their movements during sleep can lead to physical injuries such as bruising, cuts, fractures, blunt trauma, and head trauma. In fact, about 8 in 10 people with RBD experience sleep-related injuries, and up to 90% of their partners report having sleep issues due to RBD.

Secondly, RBD can cause frequent sleep disruptions, affecting the overall quality of sleep for both the individual with RBD and their bed partner. This can lead to relationship problems and marital issues.

Thirdly, untreated RBD may be an early warning sign of more serious neurological conditions such as Parkinson's disease, Lewy body dementia, or multiple system atrophy. These conditions can develop years or even decades after the onset of RBD. Therefore, early diagnosis and treatment of RBD are crucial to managing these associated risks.

Finally, RBD can be induced or triggered by certain medications, substance use, or alcohol consumption. In some cases, RBD may be an adverse reaction to antidepressants or occur during drug or alcohol withdrawal. Thus, it is important to consult a healthcare professional to review and adjust any medications or substances that may be contributing to RBD.

In summary, the risks of not treating RBD include the potential for physical injury to oneself or others, sleep disruptions, relationship problems, and the development of more serious neurological conditions. Therefore, it is important to seek medical advice and treatment for RBD to mitigate these risks and improve overall sleep quality and safety.

How common is it?

REM sleep behaviour disorder (RBD) is a rare condition, affecting an estimated 0.5% to 1% of adults. However, it is more prevalent among older adults, with 2% of people aged 50 or older affected by the disorder. The average age of onset is 61 years, and it is much more common in men—men are nine times more likely to have RBD than women.

RBD is strongly associated with certain neurodegenerative disorders. About 97% of people with isolated (idiopathic) RBD will develop Parkinson's disease, Lewy body dementia or multiple system atrophy (MSA) within 14 years of their diagnosis. Up to 36% of people with Type 1 narcolepsy have secondary (symptomatic) RBD, and about 6% of people who take antidepressants have drug-induced RBD.

While RBD is relatively uncommon, it can be difficult to diagnose, and almost half of those with the condition are unaware that they have it.

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