Children need 10-11 hours of sleep per 24. Deep stage 4 delta sleep predominates during the first 3 hours of sleep and often during the final hour of sleep in the morning. A very brief (30 seconds to a minute long) appearance of REM or dream sleep often occurs about 90-110 minutes after sleep onset. However, the first actual REM period (greater than 3 minutes) may not be seen before the second to third hour of sleep. Then the NREM-REM sleep cycle length stabilizes at about 90-100 minutes.

Children may have 7 to 9 REM or dream periods in a single night. Occasional nightmares out of REM sleep are relatively common in children between the ages of 3 and 6 years old, with a population incidence that varies anywhere from 10%-50%. The onset is usually gradual, and parents may note an earlier onset at ages 2 or 3 years old, but the child generally does not describe "frightening dreams" or nightmares until 3 or 4 years old, once language has been fully established.

The nightmare, by definition, is a long complex dream sequence that becomes increasingly frightening and anxiety-provoking towards the end and thus awakens the sleeper. Generally the course of nightmares is self-limited and heavily dependent on stressful periods or the occurrence of traumatic events in the waking life.

Nightmares usually subside or decrease dramatically in a period of weeks with the resolution of the stressor, but may persist if there has been no resolution. Even in the adult, at least 50% will report an occasional nightmare, although, frequent nightmares in adults appear to be rare, representing only about 1% of the general population.

Sleepwalking and Sleep Terrors are basically childhood sleep disorders associated with the very deep delta sleep that is the hallmark of sleep during this stage of development rather than REM/dream sleep. Sleepwalking and sleep terrors typically occur out of long episodes of stage 4 delta sleep early -- 60 to 90 minutes -- into the sleep episode when delta sleep predominates.

Sleepwalking can occur at any time after a child can walk. The peak age of occurrence, however, is from age 4 to age 8, generally disappearing sometime during adolescence -- once the percentage of stage 4 delta sleep time has decreased. The incidence of sleepwalking is estimated at 1% to 15% in the general population, clearly predominating in children over adolescents and adults.

Sleepwalking episodes can range anywhere from just sitting-up in bed to walking, or frantic "flight" attempts to "escape." In children, inappropriate behavior such as urinating in a closet is not unusual. There is no memory for episodes or associated behaviors in children. The child is very difficult to awaken and if awakened, appears confused and disoriented. Walking out of a door to the outside or through a window is not uncommon and neither or falls or injuries. Sleepwalking episodes should be discussed with the child's pediatrician for appropriate protective strategies.

Sleep Terrors are very different from nightmares. Sleep Terrors involve abrupt arousals -- again from extended periods of deep delta sleep -- that are characterized by a loud scream followed by behavioral indications to an observer of intense fear.

The child sits up in bed, lets out a loud scream, and is then observed with eyes wide open, mouth agape, and arms flaying about as if warding off some unknown/unseen assailant. The child is unresponsive to external stimulation and unaware of the presence of caretakers and/or siblings that may have come running into the bedroom. The child is not easily awakened and if attempts at arousal are made, the episode is often prolonged. If not physically awakened by the caretakers, the child will usually just lie back down and continue sleeping.

There is complete amnesia for the episode the next morning. The child has no memory of the episode if s/he awakens at its termination, but appears disoriented and confused due to the depth of the sleep state out of which the episode and final awakening occur.

The prevalence of Sleep Terrors in children is about 3% between the ages of 4 and 12 years old. Sleep Terrors gradually diminish in frequency and intensity over time and spontaneously end during adolescence, similar to Sleepwalking when the percentage of deep delta sleep time decreases. The incidence of Sleep Terrors in the adult is <1%, predominating between the ages of 20 and 30 years old during periods of high stress and chronic sleep deprivation. In the adult, there may not be complete amnesia for the episode, and there may be one intense image of being "suffocated" or "buried."

Children and adults who have a history of sleepwalking and/or sleep terrors are very sensitive to the effects of sleep deprivation and stress. Thus, it is particularly important for them to obtain their 24-hour sleep "quota," since sleep deprivation is cumulative and any accumulation of a sleep "debt" in these individuals will increase the percentage of deep, stage 4 delta sleep and thereby the risk for sleepwalking and/or sleep terror episodes to occur. Reducing stress in the lifestyle is also necessary.

Sources: ICSD (1990) - International classification of sleep disorders: Diagnostic and coding manual. Diagnostic Classification Steering Committee, Thorpy MJ, Chairman. Rochester, Minnesota: American Sleep Disorders Association, pp 145-150, pp 162-165. American Sleep Disorders Association (1997). ICSD - International classification of sleep disorders, revised: Diagnostic and coding manual. Rochester, Minnesota: American Sleep Disorders Association, pp 145-150, 162-165.

NEONATES | TODDLERS | CHILDREN | TEENS | ADULTS & SENIORS

TOP