Talking, laughing, getting out of bed or even eating during sleep are events normal to a small percentage of people, and a more significant portion of children around the world. These unconscious, undesired behaviors and actions, when persistent, group into a sleep disorder category known as the parasomnias. Scary as the name sounds, the disorders listed under this name aren’t all considered dangerous, at least compared to other sleep disorders like severe cases of sleep apnea. Still, they pose a discomfort for the people who experience them, and for their household members, too. Almost everybody has an anecdote of a time they said something funny while asleep, or perhaps left the bed and startled a parent on their way to the bathroom. A person who shouts and screams on a regular basis during sleep isn’t a delight to sleep next to, but more importantly than that, a sleepwalker who frequently gets out of bed and attempts to perform some activity risks serious injuries. Even if you didn’t pick up a sharp tool or mindlessly turn on the gas in the unconscious, clumsy state, you might merely stumble across something or trip and fall.
Other types of parasomnia pose different risks. The primary disorders classified under this category are sleepwalking, sleep terrors, disorders of arousal, sleep-related eating disorder, REM sleep behavior disorder, and isolated sleep paralysis. They are commonly divided into subcategories based on the sleep stage they most often occur in (REM or NREM), and not rarely have further variations of their own.
The group we are focusing on, the confusional arousals, belong to the arousal disorders’ category and have some similarities with sleep inertia. Below, we will clarify the terminology and distinction of these events. But for this whole puzzle to properly fit together, let’s briefly cover the different sleep stages first.
The most general distinction of sleep stages separates REM (rapid eye movement) from NREM (non-REM) sleep. NREM stage is then divided into three or sometimes four phases. All of these sleep cycles have different effects and purposes amongst one another. It works like this:
Stage 1 NREM sleep is the transition from wakefulness to sleep, lasting only a couple of minutes. In this short time window, your brain wave activity, heart rhythm, respiratory rate, and eye movements begin to slow down from their wakeful tempo, and your muscles relax (with the possibility of a twitch or kick here and there).
Stage 2 NREM sleep is the stage that usually follows the first NREM phase of sleep and introduces the first occurrence of the third stage. In this limbo phase, your body relaxes and slows down even more, your eye movements completely stop, and the core body temperature drops.
Stage 3 NREM sleep is the deep, slow-wave sleep that is most restorative and needs to happen in order for you to feel well rested in the morning. In this stage, your heart and respiratory rate hit their slowest. It usually occurs in longer periods in the first portion of your slumber and is the most easily compromised sleep phase – an individual spends less and less time in stage 3 NREM as they age, and some stimuli like alcohol can disrupt it, too.
REM stage occurs typically about an hour and a half after you fall asleep. During this state, your eyes move from side to side, and your body is at an alertness level almost reaching the wakeful state. Most of the dreaming in an individual’s sleep happens in this stage, and their limbs’ muscles are paralyzed, so as to stop them from enacting the dreams. This stage is vital for memory consolidation.
This sleep stage may include parasomnias such as REM-sleep behavior disorder, nightmares or hypnagogic and hypnopompic hallucinations.
REM-sleep behavior disorder (RBD) happens when a person’s muscles don’t get paralyzed the way they usually would during REM sleep. This results in the individual punching, kicking, jerking, swearing, shouting, etc. in their sleep. The behaviors displayed in most cases enact the more violent versions of a person’s common dream, and the high muscular activity happens due to them feeling threatened or angered. The treatment of this disorder will count on a thorough environmental “baby-proofing” session to ensure the patient will have minimal risk of injuries. This will involve covering up sharp edges, placing another mattress on the floor, next to the bed, locking away cooking knives, and so forth. In persistent cases, medication might be prescribed.
Nightmares are disturbing, frightening dreams that get scarier as they unfold. They frequently cause the person to wake up during the night out of fear, and the person remembers the content of the dreams and doesn’t feel disoriented or confused. A streak of nightmares many nights in a row might cause insomnia or evolve into night terrors. Nightmares are usually caused by stressful, traumatic events, substance or from substance abuse withdrawal. They may be connected to a person’s existing medical condition, or occur in completely healthy people. Treatments include identifying and neutralizing stressors, psychotherapy, introducing good sleep hygiene and reducing the use of stimulants.
Hypnagogic and hypnopompic hallucinations happen at the onset or offset of sleep, believed to be due to the interference of one’s REM stage in the process of awakening. A person may hallucinate shadows, animals, colors and people in the room, as well as some sounds, melodies, voices. Furthermore, one might experience floating, or seeing their own body from above, and such events may be felt as scary or enjoyable. The episodes may be interrupted by a limb jerk, and after the person learns the hallucination isn’t real, it often disappears on its own.
The disorders in this group include arousal disorders and sleep-wake transition disorders. Sleep inertia is a good example of a sleep-wake transition disorder. It marks a state in which one is halfway between being asleep and awake. That is, their body is alerted and woken up, but the sleep continues, sometimes for a couple of hours. In this state, a person’s vigilance level is lower than their daytime average, they might be a bit disoriented and their performance impaired. This may then extend into sleep drunkenness.
Arousal disorders consist of confusional arousals, sleepwalking and sleep terrors. The difference between these disorders and the sleep-wake transition disorders is that they happen during the night when you transition between different stages of sleep. Much like with sleep inertia, the result of these disorders is a state that combines wakefulness and sleep.
Disorders of arousal are highly prevalent in children, and have a familial tendency, with the other exacerbating factors including certain depressants, sleep deprivation recovery, pain, fever, stress, environmental sounds, shift work and sleep apnea, to name a few.
Sleepwalking (somnambulism) is a universally recognized behavior during sleep where one gets up from the bed and leaves the room and engages in different activities. Among the listed risk factors, this disorder, in particular, has also been linked with the use of Zolpidem, a conventional sleep medication.
Sleep terrors are second or minute long episodes of screaming and extreme fear during sleep, often coming hand in hand with sleepwalking. They differ from nightmares due to the fact that the person won’t remember them in the morning, or won’t have a clear, accurate memory of the event, much like with other arousal disorders. These parasomnias affect about 40% of children and, although frightening, aren’t a reason for much concern, as the children who experience this problem often grow out of it.
These events cause a person to partially wake up in the first third of the night, usually for under ten minutes. One may seem awake but confused, slow, disoriented and unable to properly respond when being talked to or instructed to go back to sleep. They might perform some low-difficulty activities like pulling on the blankets, moving limbs or even mumbling or saying something, but all slurred, without sense and not to the extent of actually getting out of bed. The following morning, the entire episode is frequently forgotten. Confusional arousals occur in 6% of the under-24-years-old population and affect only over 1% of people who are 65 or older.
Confusional arousals are, in their nature, completely benign and don’t pose much risk for the person who experiences them. If the issue doesn’t go away on its own, it may over time evolve into sleepwalking or night terrors. Other than that, a person who keeps waking up from deep sleep might have issues with high vigilance requiring tasks as the most restorative part of their sleep has been disrupted, resulting in sleep deprivation and daytime sleepiness. Confusional arousals may happen caused by another disorder or condition, or due to heightened stress, opioid intake, anxiety, etc.
Diagnosis and Treatment
The diagnosing of this disorder starts by a doctor requesting a medical history and a sleep pattern overview – best from a sleep diary. To rule out or confirm a primary disorder like restless leg syndrome, periodic limb movement disorder or obstructive sleep apnea, an overnight laboratory-based sleep study called polysomnography might be ordered.
If the confusional arousal is a consequence of another disorder, the therapy involves treating that. When not too invasive, this disorder doesn’t require treatment, other than staying away from triggers like stimuli or sleep deprivation and sticking to a good bedtime routine. Parents and bed partners are only to reassure the individual who experiences the confusional disorder, not interrupt the episode.