Polysomnography is a method sleep researchers use to measure how we sleep. Poly means many, somno means sleep and graph means to write. Information is gathered by simultaneously measuring brain activity, eye movement, heart rate, oxygen levels in the blood and muscle activity while we sleep. This vast collection of data makes us able to detect precisely when we fall asleep, wake up, and the different sleep stages we constantly drift between in our sleep.
A conflicting view of sleep
With the invention of polysomnography and it’s increasing use, sleep researchers have often encountered conflict between the information the polysomnography has shown and what the patient has subjectively reported. This phenomenon is what we now know as paradoxical insomnia (also known as sleep state misperception).
A patient with paradoxical insomnia will often underestimate actual sleep time and genuinely think that he has slept very little or not at all. The subjective perception of the patient will conflict with the data from the polysomnography, which will show an average amount of sleep. Often the patient will also have no or little reduced functioning the next day in spite of reportedly not sleeping very little. Paradoxical insomnia is a mismatch between how much time you think you sleep and the objective measure provided by polysomnography.
What causes paradoxical insomnia?
It's theorized that paradoxical insomnia has a strong correlation with feeling anxious about not sleeping enough. When you worry about sleep and what consequences this will have the brain interprets this worry as something dangerous and in turn, sets off your arousal system. When sleep finally comes, your sleep is light because your mind is still active and your alertness high. This form of alertness and light sleep can be misinterpreted as being awake.
The treatment of paradoxical insomnia
Cognitive behavioral therapy for insomnia (CBT-I) is effective for the treatment of paradoxical insomnia. CBT-I uses behavioral changes and sleep restriction which aim is to make you worry less about your sleep. CBT-I recommended as first-line treatment for insomnia by both the American Academy for Sleep Medicine and the European Sleep Research Society.