Understanding sleepwalking and hypnic jerks

Sleep disorders such as sleepwalking and hypnic jerks are common phenomena affecting large portions of the population. Sleepwalking, medically known as somnambulism, is a type of parasomnia that occurs during the deepest NREM (N3) stage of sleep, typically in the first third of the night. During these episodes, the brain exists in a hybrid state where motor areas responsible for movement are active, while the prefrontal cortex, which manages complex thought and consciousness, remains asleep.

Another frequent occurrence is the hypnic jerk, a sudden involuntary muscle contraction felt when transitioning from wakefulness to sleep. Often accompanied by a sensation of falling, these jerks are considered a benign form of myoclonus. Research suggests that 60 to 70 percent of the general population experiences these jerks. They are believed to result from a random burst of activity in motor pathways occurring before the body's inhibitory systems have fully established muscle paralysis during sleep onset.