One poorly understood sleep disorder is paradoxical insomnia, in which a patient complains of not being able to sleep despite objective data indicating normal duration and quality of sleep. Paradoxical insomnia was known as sleep state misperception until 2005, when the name was changed and added to the second edition of the International Classification of Sleep Disorders (ICSD).

I recently diagnosed a new patient who insisted that he barely sleeps with paradoxical insomnia. He recorded approximately one to two hours of total sleep per night in his sleep diary. The patient claims that it takes him about two hours to fall asleep and that he wakes every half-hour to hour. He follows good sleep hygiene, including using an eye mask and earplugs. He keeps his room cool and dark. However, he cannot sleep or perceives that he is not sleeping.

Paradoxical insomnia affects between 5% and 9% of the sleep-center population. The etiology is not known, but it has been suggested that the patients’ worrying causes cognitive hyperarousal, which may make them feel as if they are awake although they are asleep.

Another possibility is that patients with paradoxical insomnia may be experiencing arousals that are not detected using current polysomnogram equipment. One study, using actigraphy did show increased movement in sleep in patients with paradoxical insomnia.1

A 1997 study found higher metabolic rate both during sleep and wakefulness compared to healthy controls.2 Of note, the patients do not seem to be greatly impaired during the day. They may say they are fatigued, but do not typically report falling asleep unintentionally. Psychiatric or other medical conditions are usually absent. These patients are not malingering.

It is important to rule out secondary insomnia, which can be related to medications or medical conditions. Sleep disorders such as obstructive sleep apnea and periodic limb movement disorders may have similar symptoms, so a polysomnogram can be helpful.

Management starts with educating the patient about normal sleep-wake patterns and validating the patient’s concerns. Sometimes presenting the objective data helps reassure patients that they are getting adequate sleep. Therapies include cognitive behavioral therapy and hypnosis. Hypnotics such as eszopiclone and zolpidem have also been shown to be helpful,3 with patients often reporting significant improvement with these medications even though no great change is found in objective data.

Don’t forget many patients with and without sleep disorders misperceive their sleep time. Consider paradoxical insomnia in patients who claim that they do not sleep for any length of time on a daily basis. Current thought is that paradoxical insomnia may be multifactorial and needs further study.

Sharon M. O’Brien, MPAS, PA-C, works at Presbyterian Sleep Health in Charlotte, N.C. Her main interest is helping patients understand the importance of sleep hygiene and the impact of sleep on health.

References

  1. Hauri PJ, Wisbey J. “Wrist actigraphy in insomnia.” Sleep. 1992;15(4): 293-301.
  2. Bonnet MH, Arand DL. “Physiological activation in patients with sleep state misperception.” Psychosomatic Medicine. 1997;59(5): 533-540.
  3. Attarian H. “Paradoxical Insomnia.” Clinical Handbook of Insomnia. 2nd ed. New York: Humana Press, 2010.