Parasomnias fall under 2 broad types.
Wondering what they are?
Here is a brief overview of these types of parasomnia, along with their subtypes
1. NREM-related Parasomnias
NREM or non-rapid eye movement sleep stages comprise the first 90 minutes of a sleep cycle. These constitute the first stage of a sleep cycle, when one’s sleep is shallow, and the following 3 stages when the sleep becomes deeper. The most common NREM-related parasomnias include disorders of arousal, of which the patients have little to no memory.
Here is a list of some of them.
- Sleepwalking: Sleepwalking or somnambulism refers to the behaviours that an individual exhibits after getting out of bed during their sleep. These include episodes of walking and other complex actions, such as sorting clothes. In case you have experienced such incidents, you are most likely to not recall it after waking up.
This is because individuals are mostly unaware or unresponsive to their surroundings during sleepwalking, meaning these episodes can lead to injuries if a sufferer bumps into an object or loses balance.
- Confusional Arousal: Also called Elpenor syndrome, confusional arousals involve exhibitions of confusing behaviour or mental confusion while sleeping.
Patients may display signs of autonomic arousals, such as sped-up heartbeat or tachycardia, excessive perspiration, crying, faster breathing (tachypnea), and dilated pupils or mydriasis.
- Sexsomnia: The meaning of parasomnia of this type can be understood from its colloquial terminology itself. Individuals experiencing this type of parasomnia generally exhibit unusual sexual behaviours during their sleep.
These include engaging in masturbation, pelvic thrusting, initiating intercourse, fondling one’s bed partner, making carnal noises, and other behaviours mimicking intercourse, all the while displaying an empty and expressionless look in one’s eyes.
- Night Terrors: Night terrors or sleep terrors depict the episodes where a patient experiences extreme fear or panic, forcing them to wake up in a frightened or confused state.
Such episodes can last 30 seconds to 3 minutes, and individuals experiencing such parasomnias mostly do not remember the cause of such behaviours upon waking up.
- Sleep-related Eating Disorder (SRED): Individuals experiencing this type of parasomnia experience dysfunctional eating episodes during their sleep. There is little to no responsiveness on a patient’s part.
2. REM-related Parasomnias
The stages following the NREM stages in one’s sleep cycle constitute the REM or rapid eye movement sleep stages. As one can understand from its name, an individual’s eyes exhibit rapid movement beneath the eyelids during the REM stage while experiencing a rise in blood pressure, heart rate, and faster breathing.
Some parasomnias occurring during this phase are as follows.
- Nightmare Disorder: If your unpleasant dreams are no more limited to a few instances and have turned into a regular phenomenon, you may be suffering from a nightmare disorder.
Such recurrent episodes constitute vivid dreams depicting threats to security and survival. Unlike night terrors, nightmares are remembered by an individual and are often a result of post-traumatic stress disorder (PTSD).
- Recurrent Isolated Sleep Paralysis: A fairly common occurrence, sleep paralysis depicts the episodes during which individuals experience complete bodily atrophy, i.e., being unable to make any sort of bodily movements.
Although such episodes only last for a few minutes, experiencing them can result in anxiety about falling asleep.
- REM Sleep Behaviour Disorder (RSBD): A common phenomenon among individuals aged 50 years and above, RSBD comprises unusual movements or vocalisations, primarily responses to dreams.
This type of parasomnia is more common among individuals on specific anti-depressants and anti-anxiety medications.
Besides the above primary categorisations, some other examples of parasomnia include bedwetting or Sleep Enuresis, Nocturnal Paroxysmal Dystonia or NPD, teeth grinding or Sleep Bruxism, sleep talking, and nocturnal leg cramps.