Insomnia: Is Hyperarousal a Problem 24/7?

Hyperarousal is a term I mention when people want a quick explanation for what’s behind insomnia. The word seems to resonate. Think of hyper- as in “excessive” or “extreme”; arousal, meaning “activation” or “animation.” Or plain old hyper, meaning “very excited, nervous, or active.”

“Hyperarousal” is a pretty good way to describe the feeling of insomnia at night. But is there a test for it? Does it happen only at night, or do insomniacs experience hyperarousal 24/7?

Insomnia sufferers are hyperaroused around the clockHyperarousal is a term I mention when people want a quick explanation for what’s behind insomnia. The word seems to resonate. Think of hyper- as in “excessive” or “extreme”; arousal, meaning “activation” or “animation.” Or plain old hyper, meaning “very excited, nervous, or active.”

Many people with insomnia tell me they have an overactive mind at night. They’re chewing over a problem and just can’t stop. Or they’re thinking ahead and worrying they won’t have time to get everything done.

Some insomniacs talk about feeling wired: “Something will wake me up,” Amy explained in an interview, “and my heart’s racing and it can feel almost like an adrenaline feeling. I’m nervous and I can’t shut down—that’s the experience I have.”

“Hyperarousal” is a pretty good way to describe the feeling of insomnia at night. But is there a test for it? Does it happen only at night, or do insomniacs experience hyperarousal 24/7?

Measures of Hyperarousal in Body and Brain

When researchers test for physiological arousal, the differences that show up between people with insomnia and normal sleepers are fairly small. On measures of heart rate, metabolism, stress hormones, and possibly body temperature, the tests show, on average, that insomniacs are cranked up a notch—but just a notch—higher on the arousal scale than normal sleepers.

Studies of brain waves at night—when they involve something called power spectral analysis—are slightly more revealing. Normal sleepers’ brains cycle tidily through all the sleep stages.

The brains of people with insomnia cycle through all the sleep stages as well. But mixed in with the usual theta and delta waves are high-frequency wave forms normally associated with being awake and alert and solving problems. This beta activity that shows up in insomniacs’ brains at night suggests that low-level information processing may be occurring even as we sleep. It’s commonly cited as evidence of insomniacs’ hyperarousal at night.

These differences between insomniacs and normal sleepers may help explain the trouble we have tuning out, mentally and physiologically, at night. But neither the physiological differences nor the beta activity at night are considered to be definitive proof of insomnia.

Hyperarousal in the Daytime

You might not think that hyperarousal describes how insomnia feels during the daytime. When morning comes, your complaint is probably that you’re not aroused enough. You feel fatigued and low energy, brain-fogged and unable to think clearly. It’s a major struggle to function, let alone get through the day.

But these complaints may actually be manifestations of hyperarousal during the daytime. European researchers used high-density electroencephalography (a fine measure of electrical activity in the brain) to investigate the brain waves of insomniacs and normal sleepers when they were awake. They placed electrodes on participants’ scalp and took readings when they were in a resting state, with (1) eyes open and (2) eyes closed.

  • With their eyes open, the participants with insomnia had comparatively lower alpha power. (Alpha waves are prominent when we’re in a relaxed state of consciousness and not making an effort to do anything.) Lower alpha power would be consistent with less ability to calm down and less ability, in the face information overload, to filter out what’s unimportant or irrelevant.
  • With their eyes closed, the insomniacs experienced significantly more beta power than did the normal sleepers. In the authors’ words, “The widespread high power in a broad beta band reported previously during sleep in insomnia is present as well during eyes closed wakefulness, suggestive of a round-the-clock hyperarousal.”

If insomnia really does derive from round-the-clock hyperarousal, then treatments focused only on extending sleep may not do much to mitigate our daytime symptoms. Better solutions will improve the quality of both our nights and our days.

If you have insomnia, do you experience a feeling of hyperarousal during the daytime? How exactly does it feel?

Insomnia: Too Much Alpha Wave Activity at Night

The brains of people with insomnia are active at night, even during quiet sleep. This activity isn’t often noted in sleep studies, where the point is to identify dominant wave forms. But looking closer, scientists are discovering slight but crucial differences in insomniacs’ brain waves at night, which may explain our trouble falling and staying asleep.

“Alpha wave intrusion” is a term used to describe the wake-like brain activity observed during the deep sleep of people with fibromyalgia and major depression. Now a new study in the Journal of Sleep Research presents evidence of abnormal alpha wave activity in insomniacs’ brains at night. Here are the two main findings:

Insomnia is characterized by greater alpha wave activity at nightPicture the brain at night. It’s mostly quiet except during rapid eye movement (REM) sleep. Then clusters of neurons in the brain stem start firing away like mad. These bursts of activity are perfectly normal during REM sleep, alternating with periods of quiet non-REM sleep through most of the night.

The brains of people with insomnia are more active at night—even during non-REM sleep. This activity isn’t often noted in sleep studies, where the point is to identify dominant wave forms. But looking closer, scientists are discovering slight but crucial differences in insomniacs’ brain waves at night, which may explain our trouble falling and staying asleep.

Alpha wave intrusion is a term used to describe the wake-like brain activity observed during the deep sleep of people with fibromyalgia and major depression. Now a new study in the Journal of Sleep Research presents evidence of abnormal alpha wave activity in insomniacs’ brains at night. Here are the two main findings:

Trouble Falling Asleep

The descent from wakefulness into deep sleep occurs fairly quickly in healthy sleepers. The pressure to pay off the day’s sleep debt is strong, compelling a rapid descent into deep (slow-wave) sleep.

But in people with sleep onset insomnia, who typically take more than 30 minutes to fall asleep at night, the descent takes quite a bit longer, research shows. Insomniacs—for unknown reasons—seem to have reduced sleep pressure. Not only does it take us longer to fall asleep. It also takes us longer to descend into deep sleep, the really restorative stuff.

Why the Slow Descent?

The research team investigating alpha wave activity looked at the sleep studies of 18 good sleepers and 10 insomniacs and found one difference that occurred before sleep began. Alpha waves—associated with a relaxed, meditative state of consciousness that occurs when the eyes are closed—are predominant in the period leading up to sleep. They’re generated by neurons firing at frequencies of 7.5 to 12.5 cycles per second.

As the healthy sleepers in the study were falling asleep, the alpha rhythms in their brains began to fluctuate and decay. But the alpha wave activity in insomniacs’ brains continued going strong.

Sleep onset insomnia may have something to do with decreased alpha variability, the researchers concluded. Insomniacs are relaxed and ready for sleep—yet (again for unknown reasons) we remain stuck in alpha mode.

Waking Up at Night

Alpha waves may also play a role in sleep maintenance insomnia. Polysomnogram studies show that normal sleepers awaken at least a few times a night but are mostly unaware of these awakenings.

People with sleep maintenance insomnia, in contrast, are conscious of waking up at night. These awakenings make our sleep feel fitful and less restorative. (And some sleep maintenance insomniacs are told their problem involves alpha wave intrusion following a sleep study.)

Adults spend up to 80% of the night in non-REM sleep, and in the alpha wave study, different kinds of alpha activity occurred in the brains of healthy sleepers and insomniacs throughout non-REM sleep. Brief arousals in the healthy sleepers were characterized by alpha waves that stayed well below the frequency of alpha waves during conscious wakefulness.

But the alpha frequencies in participants with insomnia rebounded to wake levels. In this situation, a sleeper might be easily awakened by noise or movement and memories could be formed. It might account for why so many insomniacs complain of light and/or broken sleep.

The Take-Away

Higher alpha frequencies during brief arousals and lower alpha variability at the approach of sleep fit with the hyperarousal theory of insomnia, which suggests that people prone to insomnia experience higher levels of arousal around the clock. As for how to correct these alpha abnormalities, we’ll have to wait and see.

Insomnia, Memory, and Dreams

Ask insomnia sufferers what they want, and the first thing on their wish lists is “more sleep.” Or “more deep sleep”—the kind associated with feelings of rest and restoration.

I’ll go along with that. But my wish list contains a few more items.

Insomnia may impair memory, and remembering events and dreams may depend on theta activity in the brainAsk insomnia sufferers what they want, and the first thing on their wish lists is “more sleep.” Or “more deep sleep”—the kind associated with feelings of rest and restoration.

I’ll go along with that. But my wish list contains a few more items:

 

 

  1. A better memory for past events is one. My husband narrates whole sequences of his childhood as though he were reliving them again. My memories are skeletal by comparison.
  2. I’d also like to remember my dreams. My husband recalls entire movies that take place nightly in his head, but I’m lucky if I remember a snippet of a dream once in 3 weeks.

Research suggests that insomnia may have negative effects on memory, and also that the consolidation of memories for facts and events takes place largely during deep sleep, when slow brain waves predominate. Now a team of Italian researchers is claiming in a review paper that theta waves—which are slightly faster—are likewise important in the formation and recall of memories, for both waking events and dreams.

Types of Brain Waves

Day and night, neurons are firing in the brain at a mix of frequencies. When we’re alert, most neuronal activity taking place is fast, or high frequency. (Frequency is measured in cycles per second, or Hertz [Hz]). At night the brain slows down. But activity picks up again during rapid eye movement (REM) sleep. Here are the 5 types of brain activity:

  • Gamma waves, 40 to 100 Hz. Associated with intensely focused attention and effortful problem solving.
  • Beta waves, 15 to 40 Hz. Associated with a more relaxed but focused level of attention, thinking, and sensory processing.
  • Alpha waves, 8 to 14 Hz. Associated with resting, relaxation, and meditation. Also the starting point for falling asleep.
  • Theta waves, 4 to 7 Hz. Predominant during Stage 2 sleep. May also occur during very relaxed periods of wakefulness, when the mind is wandering.
  • Delta waves, 0.5 to 3.5 Hz. Predominant during deep sleep.

The mixed-frequency brain activity that occurs during REM sleep—theta, alpha, and beta—makes it look like the brain is more awake than asleep.

Theta Waves Involved in Waking Memory

Research shows that memory processing is characterized by specific waveforms occurring in memory-related areas of the brain. In particular, the Italian researchers write, the theta rhythm “seems to correlate consistently with episodic memory, . . . the ability to remember past experiences and autobiographical events.”

Memory processing involves both inner and outer areas of the brain, and EEG recordings of subjects performing cognitive tasks have shown that theta power increases in key areas during the encoding and retrieval of information. In two studies, participants were exposed to a series of words and then asked to recall them later. The authors found that (1) theta power increased only during the encoding of the items that participants were later able to recall, and (2) the amount of theta power during the encoding phase differentiated good and bad performers when it came time to recall what they learned.

Other studies have shown that theta activity increases during the retrieval of previously learned material. Still other studies have shown that a brain oscillating in theta mode before exposure to new information is primed to recall that information later on.

Theta Involvement in the Recall of Dreams

Some studies of dream recall, in which participants’ brain waves are recorded as they sleep and they’re awakened periodically and asked to report their dreams, suggest a relationship between dream recall and alpha waves. But the findings in these studies overall are inconsistent–possibly because of different study protocols.

More recent research shows that successful dream recall is associated with both alpha and theta activity in frontal areas of the brain. And, as neuroimaging studies suggest that the mechanisms underlying mental processes are similar during wakefulness and sleep, the researchers propose that it’s the relative presence or absence of theta waves that determines whether or not we remember waking events and dreams.

I don’t know if my shoddy memory is related to a deficit of theta power, or what that may or may not have to do with my predisposition to insomnia. But as long as I’m making a wish list, I’d like a better memory. In addition to more deep sleep, I think I’ll ask for more theta power, too.

Paradoxical Insomnia: What It Is & How It’s Treated

Do you normally get just an hour or two of sleep? Are there nights when you don’t sleep at all?

You may have paradoxical insomnia. Despite its prevalence, the whys and wherefores remain largely unknown. But researchers have made a little headway in recent years, and here’s what they say now.

people with paradoxical insomnia report 1-2 hours of sleep but a sleep study isn't in agreementDo you normally get just an hour or two of sleep? Are there nights when you don’t sleep at all?

You may have paradoxical insomnia. An overnight sleep study would confirm the diagnosis. Despite your perception of getting very little sleep, your electroencephalogram (EEG)—the graphic record of your brain waves produced during an overnight sleep study—would indicate that you were actually sleeping a 6.5- to 8-hour night.

This sleep disorder seems to be fairly common. About 9 to 40 percent of the people diagnosed with insomnia are estimated to have it. Despite its prevalence, the whys and wherefores remain largely unknown. But researchers have made a little headway in recent years, and here’s what they say now.

Is There Really Anything Wrong?

Formerly called pseudoinsomnia and more recently sleep state misperception, the sleep of people with paradoxical insomnia looks similar to normal sleep in a conventional sleep study. In fact, the EEG of a person with paradoxical insomnia can look identical to the EEG of a normal sleeper. Doctors used to tell their patients that nothing was wrong.

But people with paradoxical insomnia do have grounds for complaint, and scientists are now a little closer to understanding why. In a 1997 study, Michael Bonnet and Donna Arand reported that compared with normal sleepers, people with paradoxical insomnia (1) were more confused, tense, depressed, and angry, and (2) had a significantly increased 24-hour metabolic rate. This is suggestive of hyperarousal, a characteristic of people with insomnia.

Subjective vs. Objective Insomnia

Paradoxical insomnia, also called subjective insomnia, differs from objective insomnia—the type that’s more familiar. Compared with paradoxical insomniacs, objective insomniacs

  • sleep significantly fewer hours, as recorded on the EEG
  • tend to be less inaccurate at estimating total sleep time
  • may have psychological and physiological symptoms that are more severe.

In a 2002 study, Andrew Krystal and colleagues presented an in-depth analysis of brain wave patterns that shed light on more differences. Compared with objective insomniacs, paradoxical insomniacs

  • had less delta wave activity during sleep (delta waves are the predominant waveform in deep sleep, the restorative stuff). The lower the delta activity, the greater the discrepancy between the total sleep time recorded on the EEG and the sleep time estimated by the patient.
  • experienced more alpha, beta, and sigma wave activity during sleep—brain waves commonly associated with arousal, perception, and thinking. This suggests that people with paradoxical insomnia are prone to perceiving and possibly even processing information when they sleep.

Overall, then, the sleep of people with paradoxical insomnia tends to be light and characterized by hypervigilance. Scientists are not sure if this sleep disorder is simply a way station en route to objective insomnia or a completely different kettle of fish.

Treatment of Paradoxical Insomnia

There is no standard treatment for people with paradoxical insomnia. Drug-free behavioral therapies such as sleep restriction and stimulus control may not help.

If physiological hyperarousal is the main problem for insomniacs in this group, one way to address it would be through physical training. Daily aerobic exercise—and possibly the daily practice of yoga, tai chi, or qi gong—would cut down on arousal and likely promote sounder sleep.

On the other hand, a team of Italian researchers thinks the problem is mainly perceptual. These patients “may have a sort of agnosia [a partial or total inability to recognize something by use of the senses] of their sleep,” they conclude.

Investigators at The University of Alabama treated four paradoxical insomnia patients with a kind of “sleep education.” After behavioral therapies failed to help, a specialist talked to each patient about sleep and sleep staging. Together, they looked at the patient’s EEG, watched a video of the patient sleeping, and noted differences between the recording of sleep and patient perceptions. After receiving the information, 2 of the 4 patients reported falling asleep much more quickly and sleeping a lot longer.

Ralph Downey, a sleep specialist at Loma Linda Sleep Center, conducts therapy sessions for people with paradoxical insomnia in a sleep lab. Each time a patient falls asleep, she’s awakened and asked whether she thinks she’s asleep or awake. After repeated awakenings, the patient develops the ability to recognize the bodily cues that accompany sleep. Her perception of sleep becomes much closer to that recorded on her EEG.

Michael Schwartz, whose SleepQ app I reviewed last fall, believes that the same thing can be accomplished with a smart phone and an app costing just $4.99.

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