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'I've fallen asleep and I can't get up!'

By Diane Mapes

You're lying in bed, just starting to wake up, when you realize you can't move. Your chest is heavy — like somebody's sitting on it — and you're overwhelmed with a feeling of dread.

Suddenly, out of the corner of your eye, you see something move. It's a spider. No, two spiders. No three, four, a dozen or more. They're big as walnuts and slowly crawling up the bed posts of your bed and onto the blankets, scuttling ever closer towards your paralyzed body.

Sound like a cross between "Fear Factor" and "The Twilight Zone?"

It's not. It's the sort of thing people with sleep paralysis have experienced for centuries. Back in the day, the vivid hallucinations that sometimes occur with this disorder were often attributed to supernatural forces.

According to Dr. Carol Ash, medical director of the Sleep for Life Center in Hillsboro, New Jersey,  there is a powerful force at work, but it's not otherworldly.  It's called sleep.

"Sleep is a fascinating world, a complex set of neural controls," she says. "When you go into REM sleep, you'll develop skeletal muscle paralysis and that's normal. We all do that.  If that weren't the case, you'd get up and start acting out your dreams, physically going through the motions."

Unfortunately, some people — about  5 percent of the population, including singer Sheryl Crow (and her mom) — get stuck between the gears either going in or coming out of REM sleep. Their muscles remain paralyzed while their mind is awake.

"You'll be lying in bed and you can't move, you can't talk," says Ash. "It's a very scary experience."

Especially when the spiders start showing up.

Ash says some people who suffer from sleep paralysis, narcolepsy or severe sleep debt will also experience hallucinations or waking dreams. These hallucinations can be subtle — think a bell ringing or someone knocking at the door or calling your name. Or they can come straight out of a Stephen King novel.

"People will have vivid dream images projected on their brain in an awake state," she says.  "They'll not only be paralyzed, but they'll be seeing images of their room on fire or somebody coming to get them. It's a horrible place to be."

Ash says some of her patients have told her about seeing spiders or snakes crawling across their blankets, intruders creeping up on them or beating them in their beds, or wild animals gnawing on their body parts. The people don't feel pain, she says, just incredible fear.

These hallucinations — known as hypnagogic (pre-sleep) or hypnopompic (post-sleep) experiences — can  last from several seconds to several minutes and can be quite realistic. So much so that some researchers believe sleep paralysis and its accompanying visions may be responsible for bygone tales of witches and goblins and even more recent tales of alien abduction and ghostly sightings.

"Paranormal investigators may want to start asking people, 'Have you ever been evaluated for a sleep disorder?'" says Ash about these strange bedside visitations. "Maybe the bumps in the night aren't so much bumps in the night, but what our complex brains are really capable of doing."

While not being able to move for a few seconds or a few minutes can be frightening, Ash says sleep paralysis is, in and of itself, benign – at least if the episodes are infrequent (and not misdiagnosed).

She advises people affected by the condition to focus on good sleep habits. Not getting enough sleep may trigger a latent genetic predisposition. Also try to reduce stress and recognize that the weird phenomenon may simply occur from time to time.

"If these are few and far between, it's OK," she says. "But if you've moved on to the 'spiders are coming to get me stage,' go see a sleep specialist so they can help you work through it."