The Mystery Of Abrupt Rem Sleep Interruptions

Sleep is a complex and mysterious process, and while you sleep, your body cycles between being awake and asleep. During the REM stage of sleep, your eyes move rapidly, your brain is active, and dreams occur. However, several factors can cause sudden awakenings during this stage, such as sleep disorders, stress, illness, extreme tiredness, or alcohol consumption. These interruptions can lead to feelings of grogginess, disorientation, and reduced cognitive performance, commonly known as sleep inertia. Understanding the causes and consequences of sudden awakenings during REM sleep is crucial for maintaining optimal sleep quality and overall well-being.

Sleep inertia

The intensity and duration of sleep inertia vary based on situational factors, but its effects can last from minutes to several hours. Sleep inertia is usually more intense during awakenings from the biological night, and it is more common in those with alternative sleep schedules, such as shift workers.

The exact cause of sleep inertia is unknown, but there are three common theories. One theory suggests that sleep inertia is caused by an increase in delta waves in the posterior part of the brain, which are more likely to increase after periods of sleep deprivation or loss. Another theory proposes that sleep inertia is caused by high levels of adenosine, a nucleic acid compound found in the brain that plays a role in sleep and wakefulness. A third theory links sleep inertia to reduced cerebral blood flow, which is associated with chronic fatigue syndrome.

There are several strategies that can help reduce morning sleep inertia, including consistent wake-up times, exposure to natural light, and the use of gentle alarms. Caffeine intake and bright light exposure can also help restore alertness after a nap.

Parasomnias

Non-REM parasomnias involve physical and verbal activity. The sleeper is not fully awake or aware during these events and will not remember them the next day. Non-REM parasomnias usually occur in individuals between the ages of five and 25 and often run in families. Examples of non-REM parasomnias include:

• Sleep terrors: waking up suddenly in a terrified state, possibly screaming or crying.
• Sleepwalking (somnambulism): getting out of bed and moving about with eyes open but still asleep.
• Confusional arousals: appearing partially awake but being confused and disoriented to time and space.
• Sleep-related eating disorder: eating and drinking while partially awake, sometimes consuming inedible or toxic foods.

REM parasomnias occur during the latter part of the night when vivid dreaming takes place. If awakened during a REM parasomnia, the sleeper will likely be able to recall part or all of the dream. Examples of REM parasomnias include:

• Nightmare disorder: vivid dreams that cause feelings of fear, terror, or anxiety.
• Recurrent isolated sleep paralysis: temporary inability to move the body or limbs during sleep.
• REM sleep behaviour disorder (RSBD): acting out violent dreams through vocalisations or aggressive movements.

Other parasomnias that do not fall into the Non-REM or REM categories include:

• Exploding head syndrome: hearing a loud noise or explosive crashing sound when falling asleep or waking up.
• Sleep enuresis (bedwetting): bedwetting in children aged five or older that occurs at least twice a week for at least three months.
• Sleep-related hallucinations: hallucinations when falling asleep or waking up.
• Sleep-related groaning (catathrenia): repeated episodes of groaning during sleep.
• Sexsomnia: carrying out sexual behaviours during sleep.

REM rebound

Factors that can cause REM rebound include:

• Sleep deprivation
• Stress
• Withdrawal from REM-suppressing medications (e.g. selective serotonin reuptake inhibitors)
• Substance withdrawal (e.g. alcohol or cocaine)
• Depression
• CPAP titration
• Use of psychotropic drugs such as antidepressants and antipsychotics
• Recreational drug and alcohol use
• Use of certain sleep medications, such as benzodiazepines and barbiturates
• Initiation of continuous positive airway pressure (CPAP) treatment for obstructive sleep apnea

To manage REM rebound, it is important to prioritise quality sleep and address any underlying sleep issues. This may involve improving sleep hygiene, adjusting medications, and treating any contributing medical, neurological, or psychiatric disorders.

Sleep disorders

REM sleep behaviour disorder (RBD) is a parasomnia characterised by the acting out of dreams. People with RBD may shout, punch, kick, or jerk in their sleep, potentially injuring themselves or their sleep partner. This disorder is more common in older adults and is often associated with neurodegenerative diseases such as Parkinson's and Lewy body dementia.

Nightmare disorder is another parasomnia that occurs during REM sleep. It involves vivid dreams that cause feelings of fear, terror, and anxiety. Those affected often have trouble falling back to sleep and the disorder can be brought on by stress, trauma, extreme tiredness, or alcohol consumption.

Non-REM parasomnias include sleep terrors, sleepwalking, and confusional arousals. Sleep terrors involve waking up suddenly in a terrified state, while sleepwalking involves getting out of bed and moving about with eyes open, but still being asleep. Confusional arousals are characterised by partial wakefulness, with the affected person appearing confused and disoriented to time and space.

Other parasomnias that do not fall neatly into either category include exploding head syndrome, sleep enuresis, sleep-related hallucinations, sleep-related groaning, and sexsomnia.

In addition to parasomnias, there are several other categories of sleep disorders. These include central disorders of hypersomnolence (e.g. narcolepsy), circadian rhythm sleep-wake disorders (e.g. jet lag), sleep-disordered breathing (e.g. sleep apnea), and sleep-related movement disorders (e.g. restless leg syndrome).

While the exact causes of sleep disorders are not fully understood, treatment options are available. These may include medication, psychological approaches such as hypnosis or cognitive behavioural therapy, and general sleep hygiene practices such as maintaining a consistent sleep schedule and limiting alcohol consumption.

Alcohol and substance abuse

RBD is a condition where people act out their dreams during REM sleep. They may talk, shout, lash out, or thrash around, which can be dangerous to themselves and others. The use of drugs or alcohol can make the symptoms of RBD worse. People with RBD are more likely to experience severe sleep disturbances when they ingest substances, especially alcohol, marijuana, and stimulants.

Substance use can degrade sleep quality and cause insomnia or other sleep disorders. It can also trigger symptoms of RBD, such as acting out dreams in ways that meet the criteria for RBD when experiencing alcohol withdrawal. Additionally, people with insomnia have an increased risk of developing alcohol use disorder, as they may turn to alcohol as a sleep aid. This can lead to a destructive pattern where individuals drink alcohol to fall asleep but end up sleeping poorly, leading them to rely on caffeine during the day, which further disrupts their sleep.

It is recommended to avoid alcohol at least three hours before bed. Consuming alcohol before bed can lead to frequent wakings and overall low-quality sleep. Long-term alcohol use can result in chronic sleep problems and disorders like sleep apnea.

Frequently asked questions