Parasomnias. The prefix, “para,” refers to beyond and the root, “somnia,” refers to sleep. Parasomnias are a type of sleep disorder, and most occur during Non-REM 3& 4 sleep. Common symptoms among parasomnia include incomplete transition from slow-wave brain activity, automatic behavior, altered perception of environment, and some degree of amnesia.
Parasomnia doesn’t refer to a specific disorder but rather a group of them. Here are a few examples:
- Somnambulism: This is more commonly known as sleepwalking. The frequency of sleep walking is highest between the ages 11 and 12, and affects males and females equally. Children with somnambulism are usually calm and show little to no fear of their surroundings. Patients have been observed climbing through windows, attempting to walk down stairs, or leaving the house!
- Confusion Arousal: This disorder is more common in infants. A confusion arousal event usually starts with movement and moaning that eventually evolves to crying out and thrashing. Attempts to wake the infant fully will be unsuccessful. The episode will usually last for 5 to 15 minutes before the child will return to a restful sleep.
- Sleep Terrors: This disorder can be described by a patient sitting up suddenly and screaming intensely. Sleep terrors are more common in children at about 3% between the ages of 4-12. By adulthood, less than 1% of people experience night terrors.
- Recurrent Isolated Sleep Paralysis: Often shortened to sleep paralysis, the disorder is defined by being unable to move limbs, head, and trunk of your body. An episode can last from under a minute to several minutes. While being relatively short, the feeling of being paralyzed can be quite distressing and can be accompanied by hallucinations. Factors such as stress, schedule shifts, alcohol/caffeine use, and sleep deprivation are risk factors of sleep paralysis.
- Enuresis: Also known as bedwetting and it is a very common sleep disorder in young children. About 15% to 25% five year olds wet the bed and it is almost twice as likely for boys to have enuresis as girls. Most children grow out of enuresis, with only 1% to 3% of adolescence still wetting the bed.
- Exploding Head Syndrome: EHS is harmless but sounds terrifying. Patients report a terrifying loud noise accompanied by a perceived flash of light. The episode only lasts a moment, but patients might have feelings of anxiety. In most cases, EHS is not associated with pathological or epileptiform EEG changes.
Our brains are incredibly complex and most parasomnias are not fully understood. Doctors have been looking at genetics to see if these disorders can be passed down. For example, if both parents have enuresis, the there is a 77% chance their child will also have the disorder. However, not all parasomnias have been found to be linked genetics, but rather by poor sleeping habits. More research is being done every day to find out the genetic links and how best to prevent these disorders.
All Information taken from: Mason, Thornton B.A. “Genetics of Parasomnias.” Sleep Medicine Clinics, vol. 6, no. 2, 2011, pp. 229–236., doi:10.1016/j.jsmc.2011.04.002