The Nocturnal Brain: Nightmares, Neuroscience, and the Secret World of Sleep

Summary

The Nocturnal Brain: Nightmares, Neuroscience, and the Secret World of Sleep is a compilation of clinical case studies written by a physician, Guy Leschziner, who works as a neurologist and sleep physician in London. He focuses on the extremes of sleep disorders, and each chapter is a case study or collection of case studies that exemplify one of the sleep disorders.

• "Greenwich Mean Time" discusses Vincent, who has delayed sleep phase syndrome, where he falls asleep about 1 hour later each day, such that on some days, he is almost completely nocturnal. The chapter goes into a deeper discussion about the circadian rhythm, which is extremely ancient, even existing in bacteria, and thought to reflect the need to ramp up protection against oxidative stress when the sun is up.

• "In the Still of the Night" discusses non-REM parasomnias, which are extreme cases of sleep-walking and sleep behavior. The chapter discusses Jackie who rides her motor bike while she sleeps, and Alex who has all sorts of sleep-walking antics. The chapter goes into a deeper discussion about how the view that brains are "awake" or "asleep" is too simplified, and that in many cases, even in normal everyday sleepiness, parts of the brain are sleeping while other parts are awake.

• "Disney was Right" is referring to the dog in Cinderella who acts out its dreams of chasing Lucifer the cat as an introduction to rapid eye movement sleep behavior disorder. Normally in REM sleep, muscular tone is paralyzed, preventing individuals from acting out their dreams, but in,RBD, there is often violent thrashing, punching, kicking. Payel has some minor version of this, I think, and when we were learning to play racquetball, I often received backhands to my chest in bed. One thing I thought was interesting was how some motor impairments, such as in Parkinson's disease, are overcome in sleep in RBD.

• "Rumblings", discussed sleep apnea and its large effect on health outcomes. The low oxygen that occurs from stopping breathing increases oxidative stress and inflammation. Since the risk for sleep apnea is highly modified by obesity, a lot more people are presenting with sleep apnea which has a broad range of negative health consequences.

• "The Sleep-Talking Bus Driver", is kind of an aside about a strange case study that ends up being false. Linda just completely makes up information about what her boyfriend Jim is saying in his sleep and will wake him up screaming about how he is talking about beastiality and abusing her family and all this really weird stuff, but it ends up all being fake. The chapter talks about how you are vulnerable to abuse during sleep because you are not consciously aware of anything you are doing, so you have to take information at face value.

• "Weak with laughter," discusses Adrian's narcolepsy with cataplexy. Cataplexic attacks, where his legs go weak and he falls down will occur when he feels amused, often at his own bad jokes, which I found pretty entertaining. I thought it was interesting that narcolepsy is often auto-immune in origin, from a specific attack on hypocretin producing neurons. Once hypocretin is abolished in the nervous system, sleep rhythm is highly dysregulated.

• "Buzzing bees", discusses restless leg syndrome and restless chest syndromes. This was another condition that I had no idea before reading it how specifically neurological the condition was. It is caused by low brain iron and too low of dopamine activation. Dopamine levels lower with circadian rhythm and causes these sensations in the context of reduced receptors at nighttime. It often occurs in periods of reduced iron or after reduction in dopamine receptors, such as in patients being treated with L-Dopa for Parkinsons.

• "Seized by the throat" discusses epilepsy, and specifically a case of a sleep-induced seizure in the insula of a patient named Janice. She feels like she is being choked out of her sleep, which also occurs with other symptoms such as confusion and hallucinations of smell.

• "Floating eyeballs", discusses the eerie sleep paralysis and hypnogogic hallucinations that can occur when REM sleep spills over to wake. These are cardinal features of narcolepsy, but also can occur in the normal population. It is kind of the opposite of RBD, where instead of being unparalyzed during sleep, they remain paralyzed while waking up.

• "Jekyll and Hyde", was a case study about Tom who has sexomnia. He attempts to have sex with a bed partner at night without memory, and was actually charged and convicted for sexual assault when he did this with his ex-partner before even knowing that he had the condition. He assumed she was lying at the time.

• "The Waking Effects of Coffee," was about nocturnal eating and sleep-related eating disorders. These seem to occur when there is a genetic dysfunction from the reward network along with a non-REM parasomnia, and is often associated with a high propensity for addition. The activation of limbic system during sleep with non-REM parasomnia causes the individual to gorge themselves during the night.

• "A peculiar fairy tale." was about Klein-Levin Syndrome (KLS). The case follows Jamie who has a strange assortment of symptoms, which can be described as reverting to a toddler like state in the body of a teenager. Jamie becomes extremely rude and demanding, eats ravenously, sleeps a ton, fixates on childish television or songs and has childlike speech with incomplete sentences. It is thought that the syndromes may be a kind of ion channel disease (channelopathy), like migraines, with attacks varying in their frequency and duration.

• "Inception," goes into a deeper dive about dreams. The case follows Christian who has severe narcolepsy and cataplexy, but as a side-effect of his disorder has insanely vivid and lucid dreams, such that to him it feels like he has a whole other life while he dreams. The chapter then goes to into a discussion of dreams in REM sleep, and different hypotheses about the functions of REM sleeping, which include coalescing memories, processing unimportant memories, and processing emotional memories.

• The final case chapter is "Losing Sleep" and talks about insomnia, which affects a huge portion of the population. It differentiates two distinct kinds of insomnia, one where someone is severely deprived of sleep and another where someone feels that they are not sleeping but are actually getting a normal amount of sleep. He also talks about treatments for insomnia and various approaches, including CBT for insomnia and acceptance and commitment therapies.

Discussion Questions

• One of the chapters in the book was about insomnia and how it affects so many people, including the vast majority of people with depression. I’ve known people who also went through a period of insomnia, and what I found interesting while reading this book is that they first tried a program similar to what Dr. Leschziner was proposing - getting out of bed, making sure you wake up at the same time, and other improvements to sleep hygiene. And those helped a little bit, but not a ton. But then they discovered another sleep clinician, Martin Reed, who advocated for a slightly different approach that emphasizes trying not to focus in too much on sleep hygiene and focus more on reassurance that sleeping is natural and that you are a good sleeper with some things in the way that are hurting that ability. He incorporates more of the acceptance parts of CBT for insomnia. And it really helped them! The thinking is that if you're already anxious about sleeping, then needing to be meticulous about sleep hygiene can also add to that anxiety, especially if something goes wrong in your well-controlled routine. So I thought I would put that out there if anyone was struggling with it, since it's so common.

• I found it interesting that Leschziner emphasized that we don't know what dreaming is for because of its equivalence to any kind of subjective experience. We don't really know what subjective conscious experience during awake is for either and those seem to go together in my mind! Understanding the purpose of REM sleep and other stages of sleep seems really different than understanding why we dream, in the same way that understanding the neuroscience of cognition seems really different than understanding why we are conscious. Do you think that we will make any progress on answering, “why do we dream” with neuroscience, or is it just another version of the “hard problem”?

• One thing that was really surprising and interesting to me about reading this book was how many sleep disorders have pretty clear, specific neurological causes and treatments. For example, I had no idea that narcolepsy was based on the destruction of hypocretin-producing neurons. Were there any broad themes that you found to be very surprising or interesting?

• The link between Alzheimer's and deep sleep is interesting, and I wish that he had gone more deeply into the association of age and sleep. The link between deep sleep and age-related brain disorders is very interesting to me, but it is very difficult to treat or even test the association experimentally, rather than just with observational data. Is it useful or harmful to talk about observational associations between sleep quality and age-related brain disorders?

• What did you think about the conclusion at the end of the book that the amount of sleep you need is determined by what makes you not feel sleepy?

• How do you think we deal with people who commit atrocious criminal acts, like murder or rape, while they are sleeping?

• If you had the choice to not need to sleep, would you take it?

• Some of the sleep disorders discussed in the book, such as fatal familiar insomnia or KLS, had genetic components associated with them. Should we allow clinicians to alter the genes of embryos to prevent these kinds of diseases? Where should we draw the line?