[Content warning: Scary stuff, gawking at weird diseases]
My first sign that something was up was when I noticed my Sleep Medicine textbook was written by a Dr. Dement. I reassured myself that it was probably just a coincidence, while secretly knowing I would shout “Expecto patronum!” if I ever ran into him at a conference, just to be sure.
The second sign was the introductory quote. A lot of textbooks have these. They’re usually from a work of great literature, or a poem, or a song that has to do with the medical topic addressed. Anything to show that the doctors in this field are cultured, not just people who learn a bunch of biology without exploring the wider world of the arts. For the Sleep Medicine textbook, the introductory quote was from Les Mis:
But the tigers come at night
With their voices soft as thunder
As they tear your hope apart
As they turn your dream to shame
I like the song, but in context this is really creepy.
The third sign was everything in the textbook. Sleep disorders, and especially disorders of dreaming, read like something out of an Edgar Allen Poe story.
Patients with Epic Dreaming Disorder report emotionally neutral dreams with repetitive content – continually walking up endless staircases, running across unchanging landscapes, cleaning rooms, scrubbing stone walls – which start as soon as their head hits the pillow and don’t end until they awaken. They complain of fatigue upon awakening, as if they have been working all night. When placed in the laboratory, physiological indicators of sleep are normal, and there is no increase in REM sleep time (although we now know that dreams can and do occur in non-REM sleep as well). The condition is currently poorly understood, not treatable, and sufferers report difficulty just trying to get doctors to believe they exist and aren’t making it up.
Somewhat related to epic dreaming are pathological lucid dreams. Normal lucid dreams are fun experiences where you realize you’re dreaming, take control of the dream, and spend the rest of the dream riding dolphins or kissing supermodels. Pathological lucid dreamers realize that they’re dreaming, but this somehow turns the dream into a nightmare in which the dreamer is attacked by demonic figures, all while fully conscious and realizing the nature of the phenomenon. These dreamers report experiencing real pain from the attacks and sometimes go to great lengths to stay awake and avoid having to subject themselves to further dream attacks.
Lovecraft, who knew a thing or two about dreams himself, said that “the oldest and strongest fear is fear of the unknown”, and this is part of why I find night terrors so scary. Night terrors are very simple – a sleeper wakes up very suddenly out of very deep sleep, eyes dilated impossibly wide, screaming at the top of their lungs and sometimes flailing their limbs in front of them as if trying to ward something off or protect themselves from something. When asked why, they do not explain, or cannot remember. The old consensus was that there was no stimulus; the night terrors occur during deep sleep, when dreams were once not believed to be possible. Now researchers are not so sure. One proposal floated seriously in my textbook was that whatever these people see or experience is so traumatic that the brain instantly represses it upon awakening. And this repression occurs so consistently and so completely that no one in the waking world knows or will ever know what causes night terrors.
Sleep paralysis is very common. The body tries to shut down most voluntary movement in sleep so that people don’t act out their dreams; sometimes it jumps the gun and paralyzes people when they are still awake. This would be scary enough as it is, especially since the loss of voluntary control of breathing makes victims misperceive that they are suffocating or choking to death. But driven by some sort of primal urge to make sense of the experience, sufferers often go further and hallucinate monsters immobilizing them. The classic presentation is a ghost or a devil sitting on the victim’s chest, preventing her from breathing. In other cases, the monster will be visible somewhere else in the bedroom, or just a “felt presence” who is not actually seen. I remember being terrified as a child when one of my friends reported seeing the Devil in his bedroom late at night; I was pretty atheist already but I also didn’t expect this particular friend to lie, and I was always a little uncomfortable about the story until I learned that these sorts of hallucinations are actually pretty common. But it’s not just devils and monsters. One of my patients today complained that nearly every night, as she falls asleep, she sees a huge spider crawling towards her over her bedsheets. The Wikipedia article on this condition makes fascinating reading.
Narcolepsy is a disorder of sleep regulation best known for its tendency to put people to sleep suddenly and inappropriately, which can be mildly amusing to onlookers right up until it happens when the person is driving a car. To patients it seems especially unpleasant as they “live their entire lives in constant state of extreme sleep deprivation”. But the narcolepsy symptom that made the biggest impression on me was the loss of the dream-waking distinction. While healthy people are pretty good at keeping dream and reality separate, they both sort of blur together for narcoleptics and they have to guess which of their memories are dreams and which really happened. This sometimes leads to extremely unfortunate consequences – such as sexual assault allegations based on attacks later determined to have occurred in dreams.
Sleep violence is sleepwalking’s more aggressive cousin. Those who suffer from this condition will unknowingly attempt violence against their friends and loved ones in their sleep. My textbook presents the case of a man who presented to a sleep clinic because nearly every night he was beating up his wife, who slept next to him in the bed, leaving some pretty impressive bruises and understandable marital discord (while I felt bad for the couple, I also wondered why they were still sleeping in the same room; I kick my girlfriend out of bed because ze tosses and turns too much). But the granddaddy of all sleep violence cases is the one where a man drove 23 km miles to his in-laws’ house, assaulted his father-in-law, and stabbed his mother-in-law to death. Now at some point you have to wonder – are we just taking this guy’s word for it that he was asleep the whole time? And so my textbook wanders into the fascinating world of “forensic sleep medicine” – the field where experts try to figure out whether someone who says they committed a crime while sleepwalking is telling the truth. In this case, they found that he probably was – his EEG was extraordinarily irregular, consistent with a very very severe sleepwalking disorder – and in the end he was found innocent.
Prodromal dreams are very creepy and there’s a lot of debate over whether they exist as a real thing. At their worst, they seem like plain old magical thinking – dreams that warn you of a medical problem you would otherwise be unaware of, like dreaming of breast cancer, visiting the doctor, and learning you really have the disease. But research seems to back up at least some of these, with particular interest in prodromal cardiac dreams. In one study, frequent dreams about death were found to have a strong relationship with ejection fraction (a measure of cardiac health), and severe cardiac events (eg heart attacks) were found to be preceded by extraordinarily strong nightmares more often than chance. More romantic people like to think of this as “your body sending you a message”, but I don’t know if anyone’s ruled out the more prosaic explanation that people can have a pretty good idea of their cardiac health – whether through symptoms, medical test results, or educated guesses based on lifestyle – and their anxiety about this gets reflected in their dreams.
And then there’s Sudden Unexpected Death Syndrome, which is actually even worse than the name suggests. I know I’ve written about it before, but I never really get used it it being a real disease instead of something out of a horror story.
This condition occurs only in people of Southeast Asian origin. It goes like this. They are young and healthy, in their 30s and 40s. Then one night, usually around 3 AM, they start moaning in agony, thrashing about, and die suddenly in their sleep.
But it can actually be even worse than that. There are some anecdotal reports that at least some of these deaths are not as unexpected as the name of the syndrome implies, that patients have nightmares that they will soon die in their sleep. Sometimes they will go to heroic efforts to avoid sleeping. A description of such a case from Los Angeles:
He was about twenty-one; I’ve subsequently found out this is a phenomenon in Laos, Cambodia. Everybody in his family said almost exactly these lines: ‘You must sleep.’ He said, ‘No, you don’t understand; I’ve had nightmares before—this is different.’ He was given sleeping pills and told to take them and supposedly did, but he stayed up. I forget what the total days he stayed up was, but it was a phenomenal amount—something like six, seven days. Finally, he was watching television with the family, fell asleep on the couch, and everybody said, ‘Thank god.’ They literally carried him upstairs to bed; he was completely exhausted. Everybody went to bed, thinking it was all over. In the middle of the night, they heard screams and crashing. They ran into the room, and by the time they got to him he was dead. They had an autopsy performed, and there was no heart attack; he just had died for unexplained reasons. They found in his closet a Mr. Coffee maker, full of hot coffee that he had used to keep awake, and they also found all his sleeping pills that they thought he had taken; he had spit them back out and hidden them.
This happens sufficiently often among Southeast Asians that it is a recognized part of the various cultures of the region:
The nightmare demons of the Far East can be lethal. In Japan, this type of death is known as pok-kuri; the Filipinos call it bangungot or batibat; and the Hmong people of Vietnam and Laos call it tsob tsuang. In Thailand, the being to fear is the phi am or ‘widow ghost’ who comes to steal away the souls of young men. Some men defend themselves from phi am by wearing lipstick at night, so that the ghost mistakes them for women and leaves them alone.
It is now a part of American culture as well – it was a string of cases of Sudden Unexpected Death Syndrome in Los Angeles that inspired the movie Nightmare on Elm Street.
Luckily there is now a more prosaic explanation. Sudden Unexpected Death Syndrome is believed to mostly be the same thing as Brugada Syndrome, a very unusual cardiac disease caused by mutations in a gene coding for a vital heart protein. It can be controlled with an implantable defibrillator, which can restart the heart if it falls into an otherwise fatal arrhythmia.