Vicki Delien recalls one holiday season when her now 17-year-old daughter Nicole missed Thanksgiving, Christmas and New Year's Eve.

The West Allegheny High School student, who suffers from the rare neurological disorder Kleine-Levin Syndrome, slept through the holidays, awaking one day in January when she finally opened Christmas gifts alongside her family. 

Delien said her family has grappled with her daughter's debilitating condition, sometimes called "Sleeping Beauty Syndrome," which causes Nicole to periodically fall asleep for days or weeks at a time.

"She's never really adjusted to it," Delien said. "She's 17 now and it really upsets her. She's missed out on a lot."

Nicole's family used to live in Scott Township and she was a student in the Chartiers Valley School District.

At the age of 6, Nicole began experiencing the symptoms of Kleine-Levin Syndrome: She would fall into deep sleeps for days at a time. Her family would be unable to rouse her, Delien said.

"We heard it was viral, epilepsy, West Nile, she was just doing it for attention," Delien said. "It took us 25 months to land a diagnosis." 

The illness is characterized by recurring bouts of excessive sleep, punctuated by periods of confusion, lethargy, depression and overly emotional behavior.

The cause of Kleine-Levin Syndrome is not known. Delien said stress can trigger a sleeping episode: Nicole last fell into a deep sleep in February, after the family moved from Scott Township to Oakdale. 

Delien said the syndrome has upheaved her daugther's young life—causing her to miss long periods of school, extracurricular activities and family vacations. Prior to her diagnosis, someone concerned by Nicole’s persistent drowsiness reported the family to child protective services. 

The hibernation-like states have spanned as long as 64 days, during which time Nicole is unable to care for herself and requires constant supervision, Delien said. 

"She'll just be completely out of it," Delien said. "She will be completely asleep for about 19 hours a day. She will get up, but she'll be like a zombie, like she's sleep walking. And she tends to just go to the refrigerator and take out whatever she's craving." 

The Delien family appeared Tuesday on the nationally syndicated talk show The Jeff Probst Show, where discussed Nicole's struggle with the illness.

Watch a clip of the Delien family's appearance here.

Delien said the family hopes to raise awareness of the disease, or perhaps start a Pittsburgh-area support group for Kleine-Levin sufferers. 

She said they hope to reach out to other families in Western Pennsylvania who suspect their child may have the illness. 

"We've been through everything with this illness," Delien said. "There are others who need to be made aware that this is a disorder that is out there. It's a true sleep disorder that exists and people who have it need help."  

The family was whisked to Los Angeles last week to film the episode for the show, hosted by the Survivor television personality. The episode spotlights families dealing with unusual medical conditions. 

The show will feature a home video of Nicole, filmed the year that she dozed from Thanksgiving to New Year's. 

Delien said her daughter awakes from episodes with no recollection that time has elapsed. The girl's grandfather passed away during one of her slumber episodes, leaving her family to break the news to her after she awoke. 

"She only knows what happens to her when we tell her," Delien said. "She has no clue what has happened (while she is asleep) and she has no clue that she's been out of it for that long." 

Some Kleine-Levin patients can experience a remission. Delien said her daughter is now being treated with epilepsy and narcolepsy medication. The treatment, coupled with a strict regular sleeping regimen, has helped keep the illness at bay—Nicole now suffers from sleeping episodes twice a year. 

"She's just a normal kid," Delien said. "She's a very happy, bubbly teenage girl who enjoys everything and tries to be happy. When she goes into an episode it just tears everything apart."