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. 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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