The Secrets of Sleep
In February 1993, 21-year-old Jarod Allgood rose from bed and rushed out of his Cedar Rapids apartment into the dead of night. Wearing only boxer shorts, Allgood sprinted barefoot for nearly a mile down icy streets before reaching Highway 30 near Kirkwood Community College, where he was a student. There, he darted onto the highway and into the path of an oncoming semi.
Authorities, who ruled out foul play, presumed it to be a suicide. But Allgood's devastated mother knew that wasn't possible. Her son had shown no signs of depression, and his autopsy found no drugs or alcohol in his system. His death was as perplexing as it was tragic.
There was, however, one clue: a history of troubled sleep.
Twenty-five years later, University of Iowa neurologist M. Eric Dyken (88R, 90F) often returns to the Allgood case when he gives presentations. As director of UI Hospitals and Clinics' Sleep Disorders Clinic, Dyken has spent his career studying and treating patients with sleeping problems. Today he's among the doctors at the UI who, alongside researchers in the burgeoning Iowa Neuroscience Institute, tunnel into the mysterious processes at work during sleep that play a crucial role in areas such as memory, development, and health.
Although it consumes a third of our lives, sleep is a relatively new branch of medicine that in many ways remains an enigma, says Dyken. But the health benefits of a quality night's rest have never been clearer. Sleep is important for virtually every system in our body—from the brain, heart, and lungs to our metabolism, immune system, mood, and disease resistance. On the other hand, a chronic lack of sleep can be debilitating or even deadly, potentially leading to heart disease, diabetes, depression, and obesity.
Thirty-five percent of Americans get less than the minimum recommendation of seven hours of sleep in a 24-hour period, according to the Centers for Disease Control and Prevention. And sleep is often cast aside for the trappings of modern life as we check work emails in bed or binge Netflix late into the night. A recent survey by the National Sleep Foundation found that just one in 10 people consider sleep to be a top priority, well behind work, hobbies, fitness, and social lives.
"Like grandma said, most of us need seven to nine hours of sleep per night," Dyken says. "That's really hard to do, though, because, God bless America, burning the candle on both ends is how we make a million. We're a 24-hour society."
Still numb from the news of her son's death, Becky Allgood dug for answers in the days after. Jarod was a bright student who had a wide circle of friends, dated a lot, and had no enemies or romantic entanglements. The suicide theory didn't add up.
Becky learned from Jarod's roommate that her son had talked about a recurring dream in which he was running a race. The roommate also remembered a recent night when Jarod came out of his bedroom, complained of the apartment being too dark, flipped on some lights, and went back to bed, only to have no memory of it the next day.
The puzzle pieces fell into place for Becky. Jarod didn't just wake up and decide to end his life; in fact, he hadn't been awake at all. As a kid, Jarod had a tendency to sleepwalk, as did his siblings. It had always been just a harmless family quirk. Now it had become a mother's worst nightmare.
Determining the cause of death was important to Becky not only for closure, but also because Jarod's death certificate had yet to be finalized. Convincing authorities that sleepwalking was to blame, however, was an uphill battle. Says Becky: "I felt like they were patting me on the head saying, ‘This woman is crazy.'"
As many as 70 million people in the U.S. suffer from a sleep disorder, according to the American Sleep Association. Patients with insomnia and drowsiness seek help at the UI Sleep Disorders Clinic for problems ranging from narcolepsy to restless legs syndrome. The majority of patients seen in the sleep laboratory, however, struggle with obstructive sleep apnea, which occurs when a person repeatedly stops and starts breathing in their sleep. The disorder is often characterized by loud snoring and occurs when muscles in the back of the throat relax to a point that it constricts the airway. Apnea can severely reduce the amount of quality sleep a person gets, and when coupled with an existing issue like heart disease, the depletion of blood oxygen can even prove fatal.
Cate Koeppen of North Liberty, Iowa, was referred to the UI Sleep Disorders Clinic by her family doctor when constant fatigue and a general lack of energy began affecting her life. The 46-year-old mother would fall asleep each night watching TV with her kids and even caught herself drifting off at her desk at work on slow days.
UI doctors brought Koeppen in for a sleep study, where they hooked her up with sensors to monitor her breathing overnight. The next morning, she was stunned when clinicians told her that she had restricted airflow an average of 96 times an hour. In other words, her apnea was so severe that she stopped breathing once or twice a minute in her sleep.
Doctors prescribed nightly use of a bilevel PAP machine, which delivers pressurized air through a mask to keep the patient's throat muscles from collapsing. The results were immediate. Sleeping without interruption, Koeppen awoke feeling truly rested for the first time in years.
"I'm more alert, better able to make connections, and more engaged with what's happening," Koeppen says. "I just wish I had talked with my doctor about my sleepiness a lot sooner. I'd been living with it for at least a couple years."
More than 29 million Americans suffer from obstructive sleep apnea, according to the American Academy of Sleep Medicine. The university's sleep laboratories and clinics at UI Hospitals and Clinics, Center for Disabilities and Development, and Iowa River Landing conduct about 3,000 sleep studies a year for patients like Koeppen, including new tests that can be performed at home.
George Richerson (87MD, 87PhD, 87F), chairman of the UI Department of Neurology, says beyond the immediate effects of a poor night's rest, sleep disorders can lead to long-term hypertension in patients, as well as an increased risk of stroke and heart disease. While sleep apnea is all too common, other lesser-known disorders can also present serious dangers. Richerson recalls a patient he once treated for REM sleep behavior disorder—when a person acts out their dreams because the paralysis that usually accompanies deep sleep is absent. One night, the man dreamt he was playing football and—to his wife's horror—ran across his room at full speed and tackled his dresser. He suffered a broken shoulder.
The good news, says Richerson, is that a greater awareness of sleep disorders today has led to more options than ever to find help. "Years ago, people would ignore sleep problems; you were weak if you needed to sleep," Richerson says. "It's becoming more appreciated now that it's important for your health and that a lack of sleep can cause a degradation in your cognitive performance."
Cognition and sleep is the focus at Ted Abel's laboratory in the UI's Pappajohn Biomedical Discovery Building, where researchers fight off drowsiness—though not their own. The lab team gently nudges research mice awake to study the animals' ability to form memories on just five hours of sleep, as opposed to their usual 11 hours.
Abel, who came to the UI last year from the University of Pennsylvania to head the newly established Iowa Neuroscience Institute, is the Roy J. Carver chair in neuroscience and a leading investigator of sleep and memory. In a series of studies at Pennsylvania and now at Iowa, Abel and his lab examined why mice who are sleep-deprived after training in a task— finding their way through a maze, for example—are worse at remembering how to execute it the next day compared to their well-rested counterparts.
Since first making that connection more than a decade ago, Abel and his collaborators have burrowed ever deeper into sleep—first studying its effect on behavior, then the region of the brain that controls episodic memory called the hippocampus, then individual cells, and now molecules. Abel has found that sleep deprivation hurts memory permanence by stymying the molecular signaling between neurons in the hippocampus. When animals are eventually allowed to sleep, those neurons reconnect and enable memories to take shape permanently. Sleep essentially rewires the brain, says Abel.
Now Abel's team is learning how to actually block the biological effects of sleep loss by identifying a key molecule. In manipulating that molecule, the scientists have been able to produce mice whose memories are resilient to sleep loss. "The research in this field has really grown," Abel says. "We've gone, frankly, from discussions in the first half of the 2000s where the question was, ‘Does sleep play a role in memory?' Now the question is, ‘How does it work?' And we've developed a lot of tools to study it."
Inside the UI Department of Psychological and Brain Sciences, professor and department chair Mark Blumberg asks a question that's crossed the mind of anyone who's cradled a sleeping newborn: What's happening when babies' arms twitch, their legs jerk, and their mouths curl into a smile?
Twitching occurs in almost all mammals and birds during the rapid eye movement, or REM, stage of sleep, particularly in young animals, explains Blumberg. Those subtle movements were long ignored as unimportant byproducts of the dreaming brain. But when researchers in Blumberg's lab looked closer, they found an explanation that's much more interesting: Twitches are in fact a key part of babies' early sensorimotor experience and development of the nervous system.
Blumberg discovered that when infants enter REM sleep, areas of their brainstem begin firing in bursts, which causes their faces and limbs to twitch. In return, the brain receives feedback from the movement. Simply put, babies' brains are hard at work monitoring sensory information and learning how to use their limbs, especially while asleep.
"Every muscle that's associated with movement is activated in this way during sleep," says Blumberg, who has been studying twitches as a window into early development for more than a decade. "Each twitch produces a cascade of information to the developing brain, all of it happening very fast."
Blumberg's studies have typically focused on rat pups, which twitch hundreds of thousands of times a day while asleep. But in a recently completed study, Blumberg recorded the sleep movements of human infants for the first time. At first glance, twitches in humans are relatively slow and more prolonged compared to rats. But interestingly, when the video of the sleeping babies was sped up several-fold, Blumberg's team saw that twitching in the human infants was nearly identical to that in rats.
The research could one day shed light on other areas of medicine. Blumberg's lab is in the early stages of studying how sleep in early life is linked to certain neurodevelopmental and psychiatric disorders, including autism and schizophrenia.
"What makes sleep and development so uniquely connected is that when we're young, we're sleeping a lot—16 hours a day of sleep, including eight hours a day in REM sleep," Blumberg says. "More and more evidence is accumulating that if you disrupt sleep during development, it can have longstanding and maybe permanent effects."
Seeing strides made in sleep treatment and research at the UI and beyond is heartening for Becky Allgood, who became an advocate for sleep disorder awareness after her son's death. That's when she first connected with the UI's Dyken, who helped her successfully petition to have sleepwalking listed as the cause on her son's death certificate—a first in Iowa. Allgood made the national talk show rounds in the 1990s, including an interview with Oprah Winfrey, and worked with sleep experts who highlighted her son's case in papers and medical textbooks. She fielded calls for years from people around the country whose lives were affected by sleep disorders.
Since then, researchers have learned that sleepwalking is even more common than once thought. A Stanford study earlier this decade found that 3.6 percent of U.S. adults, or 8.4 million people, sleepwalk each year. Formally known as somnambulism, the disorder can take many forms, from getting up and raiding the refrigerator while asleep to driving a vehicle without fully waking. Sleepwalking is most common in children and is typically outgrown by the teen years. Experts say the occasional sleepwalking episode isn't usually a cause for concern, but a person should seek treatment if sleepwalking occurs frequently or results in dangerous behaviors.
Allgood will never know why Jarod's childhood sleep problems resurfaced that fateful night, but she takes a measure of comfort in his case serving as a cautionary tale. That's why she still tells Jarod's story every chance she gets. "You don't ever forget your child," she says.