Rem Sleep Disorder: A Dangerous Diagnosis?

REM sleep behaviour disorder (RBD) is a parasomnia in which people act out their dreams while in the REM stage of sleep. This can involve violent behaviour and can lead to injury to the person with RBD or anyone they share a bed with. RBD is relatively rare, affecting between 0.5 and 2% of the population, but it's important to seek treatment to prevent accidental injury.

Risk of injury to self and others

REM sleep behaviour disorder (RBD) can cause injury to the person affected by the disorder and anyone they share a bed with. The person with RBD may act out their dreams, which can include violent nightmares. This can lead to sleep-related injuries such as bruising, cuts, fractures, blunt trauma, and head trauma. In some cases, these injuries can be life-threatening.

The risk of injury is higher if the person is having an aggressive or frightening dream. The movements involved in RBD may become more violent over time. About 8 in 10 people with RBD experience sleep-related injuries. Up to 90% of partners of people with RBD have sleep issues, and over 60% have experienced a physical injury.

To prevent injury, it is important to create a safe sleeping environment. This may include removing sharp, glass, and heavy objects from the bedroom, placing pillows or padding around the bed, and sleeping on a mattress on the floor. If symptoms are severe, the person with RBD may need to sleep alone in a different room. They should also avoid alcohol, as this can trigger an episode of RBD and make the condition worse.

Treatment for RBD can include medication such as melatonin or clonazepam, which can help to reduce symptoms and prevent injury.

Coexistence with other neurological conditions

REM sleep behaviour disorder (RBD) often coexists with other neurological conditions, including Parkinson's disease, Lewy body dementia, and multiple system atrophy (MSA). These conditions are called alpha-synucleinopathies. RBD can also precede the development of these neurodegenerative diseases.

One study found that 38% of men aged 50 or older with RBD eventually developed Parkinson's disease, Lewy body dementia, or multiple system atrophy, usually within 13 years. That number increased to nearly 81% in a follow-up study conducted 16 years later. These findings have been confirmed in subsequent research; 30% of individuals with RBD developed a Parkinsonian disorder or dementia within 3 years, and 66% did so within 7.5 years.

RBD is also associated with narcolepsy, specifically Type 1 narcolepsy, and stroke.

People with RBD are at a higher risk of developing neurological conditions, especially if the RBD occurs spontaneously and isn't due to narcolepsy or medication. About 97% of people with isolated RBD will have Parkinson's disease, Lewy body dementia, or multiple system atrophy within 14 years of diagnosis.

Diagnosis criteria

To receive a diagnosis of REM sleep behaviour disorder (RBD), a patient must undergo an in-lab video sleep study, or polysomnogram (PSG). These sleep studies are tests that record specific body functions during sleep, such as:

• Breathing rate and airflow
• Brain wave activity
• Muscle movements of the chin and upper extremities

According to the International Classification of Sleep Disorders, a diagnosis of RBD requires all of the following:

• Repeated episodes of sleep-related vocalisation and/or complex movement behaviours
• The behaviours are documented by a sleep study (polysomnography) and occur during REM sleep or can be assumed to happen during REM sleep based on the patient's clinical history
• The sleep study shows that the patient experiences REM sleep without atonia (muscle paralysis)
• The patient does not have seizure-related activity during REM sleep
• The sleep disturbances are not better explained by another sleep disorder, medical condition or mental health condition. They are also not caused by medication side effects or substance use disorder

Treatment options

Symptomatic Treatment

The main goal of symptomatic treatment is to create a safe sleeping environment for the patient and their bed partner. This involves safety measures and medication.

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 symptoms are severe, the bed partner may need to sleep in a separate room
• Avoid drinking alcohol, as this can trigger an RBD episode and make the condition worse

Medication

• Melatonin: This is considered the first-line medication for treating RBD as it rarely causes side effects. It is a hormone that the body's pineal gland naturally makes, and it's essential for regulating the sleep cycle. A baseline dose is usually recommended, which is then increased until symptoms improve.
• Clonazepam: This is a sedative that has been shown to help treat RBD, although it is not known why. It can cause unpleasant side effects, so it is usually only prescribed if melatonin doesn't help.
• Pramipexole: This 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.
• Other medications that have shown some degree of efficacy in short- and medium-term randomised clinical trials include rivastigmine, memantine, 5-hydroxytryptophan, and the herbal medicine yokukansan.

Prognostic Counselling and Longitudinal Follow-Up Surveillance

People with RBD will likely need to see their healthcare provider regularly to check for signs of the neurological conditions that are strongly associated with it.

Prevention techniques

Safety Measures

• Remove sharp, glass, and heavy objects from the bedroom.
• Place pillows between the sleeper and surrounding structures, such as the headboard or nightstand.
• Place a mattress on the floor next to the bed or use padded bed rails.
• Sleep in a sleeping bag.
• Avoid drinking alcohol, as it can trigger an episode and worsen the condition.

Medication

• Melatonin: This is considered the first-line medication for treating RBD, as it rarely causes side effects. It is a hormone that helps regulate the sleep cycle.
• Clonazepam: A sedative that helps reduce nightmares and dream enactment behaviours in people with RBD. However, it can cause unpleasant side effects.
• Pramipexole: A dopamine agonist that has been shown to reduce symptoms in people with RBD. This medication may work because RBD is believed to be a dopaminergic deficiency disorder.

Frequently asked questions