Rem Sleep Disorders: Exploring The Unconscious Mind

REM sleep behaviour disorder (RBD) is a sleep disorder characterised by the loss of normal skeletal muscle atonia during REM sleep. During the REM phase of sleep, the muscles in the body usually enter a state of temporary paralysis. However, in a person with RBD, this paralysis is incomplete or even absent, causing the person to act out their dreams. These dreams are often vivid and violent, and the person may shout, punch, kick, jump out of bed, and engage in other actions linked to being awake. The person may be unaware of these movements, but their bed partner may raise concerns. RBD is a parasomnia, and it is more common in men over the age of 50. It is also a strong predictor of the onset of neurodegenerative diseases such as Parkinson's disease, Lewy body dementia, and multiple system atrophy.

REM Sleep Behaviour Disorder (RBD)

In people with RBD, this paralysis during the REM stage is incomplete or absent, allowing them to act out their dreams physically. This can include talking, yelling, punching, kicking, jumping out of bed, and flailing their arms. These dream-enacting behaviours can result in injuries to the person with RBD and their bed partner, and cause a reduced quality of life and severely disrupted sleep.

RBD is usually seen in middle-aged to elderly people and is more common in men. It is often associated with neurodegenerative diseases, such as Parkinson's disease, Lewy body dementia, and multiple system atrophy. In some cases, RBD precedes the development of these neurodegenerative diseases by several years.

The exact cause of RBD is unknown, but it may be related to dysfunction in certain neural pathways in the brain that control muscle activity during REM sleep. Treatment for RBD involves a combination of lifestyle changes, medication, and injury prevention techniques. Medications such as clonazepam and melatonin are often used to reduce symptoms. Creating a safe sleep environment is also crucial, which may include removing sharp objects from the bedroom and padding the floor around the bed.

RBD is a parasomnia

REM sleep behaviour disorder (RBD) is a parasomnia. Parasomnias are sleep disorders in which strange or dangerous events occur that disrupt sleep. RBD is characterised by the loss of normal skeletal muscle atonia during REM sleep, and is associated with vivid dreaming and prominent motor activity. The paralysis that usually occurs during REM sleep is incomplete or absent in people with RBD, allowing them to act out their dreams. This can include talking, yelling, punching, kicking, sitting up, jumping from bed, and arm flailing.

RBD is usually seen in middle-aged to elderly people, and is more common in men. It is often associated with other neurological conditions, such as Parkinson's disease, Lewy body dementia, and multiple system atrophy. In fact, RBD is a strong predictor of progression to a synucleinopathy, usually Parkinson's disease or Lewy body dementia. RBD may also be symptomatic of narcolepsy, Guillain-Barré syndrome, limbic encephalitis, and Morvan's syndrome.

The exact cause of RBD is unknown, but it may be linked to certain neural pathways in the brain. Brainstem circuits that control atonia during REM sleep may be damaged, and imaging studies have shown that RBD can be accompanied by changes in multiple neurotransmitter systems.

RBD can be treated with medication and by adapting sleep habits. Melatonin and clonazepam are the most frequently used medications, and are comparably effective, but melatonin is a safer alternative as clonazepam can produce undesirable side effects.

RBD is a predictor of synucleinopathy

REM sleep behaviour disorder (RBD) is a parasomnia in which individuals lose the paralysis of muscles (atonia) that is normal during rapid eye movement (REM) sleep. This allows people with RBD to act out their dreams or have other abnormal movements or vocalisations. Abnormal sleep behaviours may appear decades before any other symptoms, often as an early sign of a synucleinopathy. Synucleinopathies are neurodegenerative diseases characterised by the abnormal accumulation of aggregates of alpha-synuclein protein in neurons, nerve fibres or glial cells.

RBD is considered the expression of the initial neurodegenerative process underlying synucleinopathies and is the most important marker of their prodromal phase. RBD is widely considered a prodromal synucleinopathy, as most people with RBD develop overt synucleinopathy within about 10 years. On autopsy, 94% to 98% of individuals with polysomnography-confirmed RBD are found to have a synucleinopathy, most commonly dementia with Lewy bodies or Parkinson's disease.

RBD is a strong predictor of synucleinopathy. It is estimated that up to 90% of patients with "isolated" RBD will eventually develop one of the alpha-synucleinopathies. RBD is found to occur, on average, eight years before the presentation of the core motor or cognitive symptoms required for the clinical diagnosis of Parkinson's disease or dementia with Lewy bodies. This provides increasing evidence to suggest that in most cases, RBD is the early manifestation or prodrome of a clinically defined neurodegenerative disease.

There is a clear link between RBD and alpha-synucleinopathies. RBD is one of the most specific predictors of synuclein-mediated neurodegenerative diseases. RBD is a strong indicator of the development of Parkinson's disease, multiple system atrophy and dementia with Lewy bodies.

RBD symptoms and treatment

REM sleep behaviour disorder (RBD) is characterised by dream enactment and loss of REM atonia. The person may be awakened or wake spontaneously during the attack and vividly recall the dream that corresponds to the physical activity. RBD is usually seen in middle-aged to elderly people and more often in men.

The exact cause of RBD is unknown, but it may happen along with degenerative neurological conditions such as Parkinson's disease, multisystem atrophy (also known as Shy-Drager syndrome) and diffuse Lewy body dementia. In 55% of people, the cause is unknown, and in 45%, it’s linked with alcohol or sedative-hypnotic withdrawal, tricyclic antidepressant (such as imipramine), or serotonin reuptake inhibitor use (such as fluoxetine, sertraline, or paroxetine) or other types of antidepressants (mirtazapine).

RBD is often accompanied by other neurological conditions like Parkinson’s disease, Lewy body dementia, multiple system atrophy, narcolepsy, or stroke. In many cases, RBD precedes the development of one of these neurodegenerative diseases.

The treatment for RBD is tailored to an individual and can involve a combination of lifestyle changes, medication, and injury prevention techniques.

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 REM sleep behaviour disorder 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.

Injury prevention techniques 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 separate beds or separate rooms

RBD diagnosis

REM Sleep Behaviour Disorder (RBD) is a parasomnia characterised by sudden body movements and vocalisations while experiencing vivid dreams during REM sleep. Diagnosis of RBD can be complex and requires ruling out other potential causes.

The first step in diagnosing RBD is to conduct a physical and neurological exam to rule out other potential causes, such as alcohol or medication use, or other sleep disorders like narcolepsy. The neurological exam is often normal, but symptoms and signs of Parkinson's disease, such as hand tremors or muscle stiffness, may be present and suggest an underlying neurological cause of RBD.

If RBD is suspected, the next step is to perform a polysomnogram, also known as an overnight sleep study. This test is typically conducted in a sleep study centre, where the person is monitored while they sleep. Sensors are attached to the body to record various parameters, including brain and heart activity, eye and muscle movements, and respiratory patterns. A video recording is also made to observe behaviours during sleep. The polysomnogram will show an increase in muscle tone associated with the REM sleep EEG pattern in people with RBD, whereas healthy individuals exhibit muscle atonia during REM sleep.

In addition to the polysomnogram, a clinical history is also essential for diagnosis. This includes information about the frequency and nature of the episodes, as well as any medications or substances used. It is also important to rule out other sleep or mental health disorders that could be causing the symptoms.

According to the American Academy of Sleep Medicine's International Classification of Sleep Disorders, four criteria must be met to receive a diagnosis of RBD:

• Repeated episodes of acting out dreams with vocalisations or arm and leg movements that correspond to the dream content.
• Episodes occur during REM sleep, as confirmed by the polysomnogram or clinical history.
• Episodes include sleep without atonia, as confirmed by polysomnography.
• The episodes are not attributed to another disorder, medication side effects, or substance abuse.

If you suspect you may have RBD, it is important to consult a doctor, who may refer you to a sleep specialist for further evaluation and diagnosis.

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