Importance Childhood sleepwalking and sleep terrors are 2 parasomnias with a risk of serious injury for which familial aggregation has been shown. 
 
 Objectives To assess the prevalence of sleepwalking and sleep terrors during childhood; to investigate the link between early sleep terrors and sleepwalking later in childhood; and to evaluate the degree of association between parental history of sleepwalking and presence of somnambulism and sleep terrors in children. 
 
 Design, Setting, and Participants Sleep data from a large prospective longitudinal cohort (the Quebec Longitudinal Study of Child Development) of 1940 children born in 1997 and 1998 in the province were studied from March 1999 to March 2011. 
 
 Main Outcomes and Measures Prevalence of sleep terrors and sleepwalking was assessed yearly from ages 11/ 2 and 21/ 2 years, respectively, to age 13 years through a questionnaire completed by the mother. Parental history of sleepwalking was also queried. 
 
 Results The peak of prevalence was observed at 11/ 2 years for sleep terrors (34.4% of children; 95% CI, 32.3%-36.5%) and at age 10 years for sleepwalking (13.4%; 95% CI, 11.3%-15.5%). As many as one-third of the children who had early childhood sleep terrors developed sleepwalking later in childhood. The prevalence of childhood sleepwalking increases with the degree of parental history of sleepwalking: 22.5% (95% CI, 19.2%-25.8%) for children without a parental history of sleepwalking, 47.4% (95% CI, 38.9%-55.9%) for children who had 1 parent with a history of sleepwalking, and 61.5% (95% CI, 42.8%-80.2%) for children whose mother and father had a history of sleepwalking. Moreover, parental history of sleepwalking predicted the incidence of sleep terrors in children as well as the persistent nature of sleep terrors. 
 
 Conclusions and Relevance These findings substantiate the strong familial aggregation for the 2 parasomnias and lend support to the notion that sleepwalking and sleep terrors represent 2 manifestations of the same underlying pathophysiological entity. 

 If you have a history of sleepwalking, chances are your children will be somnambulists too. 
 
 A new study from Montreal researchers adds support to the growing belief that behaviours like sleepwalking and sleep terrors run in families. The findings were published Monday in the journal JAMA Pediatrics. 
 
 The offspring of parents who are or were sleepwalkers are between three and seven times more likely to sleepwalk than other children, report the researchers, from the Centre for Advanced Research in Sleep Medicine at Sacre Coeur Hospital, a teaching hospital of the University of Montreal. 
 
 The likelihood rises if both parents have a history of sleepwalking. Researchers found that in families with two parents who are or were sleepwalkers, nearly two-thirds of the children experienced sleepwalking incidences. 
 
 Among the children studied, about 47 per cent of the sleepwalkers had one parent with a history of sleepwalking. Nearly 23 per cent of the children who were sleepwalkers had parents with no history of somnambulism. 
 
 "Not all sleepwalking is problematic," noted first author Dominique Petit, a research assistant at the centre. 
 
 "Very often you don't need to do anything with sleepwalking. [But] in some rare cases there's potential for injury." 
 
 Sleepwalkers can navigate around their households with relative ease — for instance, they can climb or descend stairs. They may even perform tasks like preparing and eating a snack. They do not remember the incident later. 
 
 Petit said sleepwalkers can get hurt on occasion. She noted there have been reports of children dying of hypothermia after leaving their homes in winter and falling back into a deeper sleep in the snow. 
 
 Petit said it's recommended that parents consider an alarm for doors if children who sleepwalk tend to leave the house. 
 
 Sleepwalking is more common among children than adults. The research was designed to estimate how common sleep terrors and sleepwalking are among children, to look for links between the two behaviours and to see if they ran in families. 
 
 Child with sleep terror may be agitated by hug 
 
 The researchers followed 1,940 children in Quebec from the ages of 1 ½ or 2 ½ to 13. Parents were asked annually whether their children experienced sleep terrors and sleepwalking, and whether they had a history of sleepwalking. 
 
 Sleep terrors were common, with about 56 per cent of children experiencing this sleep disturbance at some point during the study period. They are most common at younger ages; 34 per cent of 18-month-old kids were reported to have sleep terrors. But the number drops as children get older, with 13 per cent experiencing night terrors at age five and only five per cent at age 13. 
 
 Petit said she believes these figures may be too high, noting some parents may confuse nightmares with sleep terrors. 
 
 The confusion is understandable. Both may cause a sleeper to cry out, scream or thrash about in bed. But a child having a nightmare will want to be cuddled and reassured when awakened from the dream. A child experiencing sleep terrors may not fully awaken and will become more agitated if hugged; he or she may interpret the touch as being part of the frightening scenario playing out in their brain. 
 
 Nightmares typically happen during the middle or late portion of the night. Sleep terrors often happen early in the sleeping period, generally during the first third of the night. 
 
 The pattern of sleepwalking rises through childhood; it is uncommon in young children but increases with age. In the study, the peak time for sleepwalking was between the ages of 10 and 13, with just over 13 per cent of children reported as occasionally sleepwalking. 
 
 The behaviours appear to be linked. At least a third of the children who had sleep terrors went on to be sleepwalkers. 
 
 "More and more it's the accepted idea that they're part of the same condition," Petit said. 
 
 These sleep disturbances are known to be triggered by fatigue, sleep deprivation and fevers. 

 (CNN) Does your little one suffer from sleep terrors? Then get ready to lock the window and doors, because they might soon sleepwalk, too. A study of nearly 2,000 children in Quebec over a 12-year period found that as many as a third of the children who had early childhood sleep terrors became sleepwalkers later. 
 
 "That's interesting because it can help parents know that 'Hey, if my little one has sleep terrors, and several of them, then perhaps he or she might be more at risk for sleepwalking when they are between the age of 10 and 13," said Hansa Bhargava, a pediatrician with Children's Healthcare of Atlanta. 
 
 And if you were a sleepwalker in your childhood, then your child is likely to be one, too. The study, conducted by Montreal's Center for Advanced Research in Sleep Medicine and published in JAMA Pediatrics, found 47.4% of children with one sleepwalking parent took nighttime strolls. When both parents had a history of sleepwalking, the number rose to 61.5%. 
 
 "It's definitely genetic," Bhargava said. "Prevention is really the cure in these situations. You want to make sure the child is not overtired, stressed out, over-scheduled. And have a nice calming ritual at bedtime so the child can actually calm himself down before going to sleep." 
 
 'Monsters' or sleep terrors? 
 
 "A sleep terror is not a monster under the bed, although it's so scary for parents that it can seem like that at the time," Bhargava said. "What happens is that the child wakes up screaming, crying, terrified and may not even recognize you or remember what happened. It's a frightening experience, both for the child and the parent." 
 
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 In the study, most sleep terrors occurred between ages 36 months and 5 years old, but they can happen all the way to age 13. For some children they can be transient -- defined in the study as having terrors before age 4 but none after. Others have persistent terrors -- continuing after age 5. The study found twice as many children with a parental history of sleepwalking had persistent sleep terrors. 
 
 "It's not the child's fault; don't yell at them or feel like they are not talking to you," Bhargava advised. "Just be there to calm the child and get them to go back to sleep." 
 
 Triggers and precautions 
 
 According to Bhargava, children will be at the highest risk for a sleep terror if they are sick, or about to become sick, haven't been getting enough sleep or are stressed or in a noisy environment. 
 
 The same is true for sleepwalking. 
 
 "The message is the same," Bhargava said. "Look at the child's life, see where the stress might be adding up, and reduce that. Take those cell phones away, take the technology away and make sure they adhere to a good bedtime." 
 
 Sleepwalking, also called somnambulism , usually occurs during the deeper stages of sleep, stages 3 and 4, when it's harder to wake up. While most sleepwalkers outgrow it by the teen years, some never stop or have relapses during adulthood. 
 
 Sleepwalking can be anything from sitting up in bed, to getting up and taking a few steps before going back to sleep, to opening up the closet door and urinating in it. It can even lead to leaving the house, Bhargava said. 
 
 "It can be really scary to a parent when their child does this," she said. "They may be very groggy, may not know what they are doing. Again, know that your child is in a deep sleep and just lead them back to bed." 
 
 And it's a good idea to sleepwalk-proof the house, by removing sharp or breakable things, not using a bunk bed and placing safety gates on stairs. 
 
 "Could they fall down the stairs? Sure," Bhargava said. "It can be very dangerous. It's also good to be sure the house and windows are locked, and the alarm is on. And take precautions so they don't trip over clutter. Those things can happen, and it's good to be mindful of that."
– Kids whose parents sleepwalked are more likely to do it themselves—and sleep terrors may be a precursor to sleepwalking as well, according to a new study out of Montreal published this week in the journal JAMA Pediatrics. Not that sleepwalking, also called somnambulism, is necessarily a big deal. "Not all sleepwalking is problematic," the lead author tells CBC News. "Very often you don't need to do anything with sleepwalking. [But] in some rare cases there's potential for injury." She adds that sleepwalkers, who tend to be 10 to 13 years old, often climb stairs or fix snacks without issue, but can run into problems in cases of those who go outside and suffer hypothermia or other problems. The study of almost 2,000 children aged 1.5 to 13 found that almost half of those who sleepwalked had a parent who did. Nearly two-thirds of kids whose parents both sleepwalked also did, while just a quarter of those whose parents didn't sleepwalk were somnambulists. "It's definitely genetic," another researcher tells CNN. "Prevention is really the cure in these situations. You want to make sure the child is not overtired, stressed out, over-scheduled. And have a nice calming ritual at bedtime so the child can actually calm himself down before going to sleep." The same can be true for kids with sleep terrors, though unlike when a child has a nightmare, cuddling can actually make sleep terrors worse as the child tends not to come fully awake and may not recognize the comforter. (This man died while sleepwalking.)