Paradoxical insomnia (previously called sleep state misperception) is characterized by complaints of little or no sleep over long periods of time without the level of impairment expected with such a level of sleep deprivation. Patients often describe heightened awareness of their surroundings when lying down to sleep. Sleep study reveals normal sleep architecture with normal sleep onset latency and sleep efficiency, but with subjective patient reports indicating prolonged sleep onset latency and poor sleep efficiency. Treatment usually involves patient reassurance. Behavioral therapy and sedative-hypnotics have also been tried.
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• Paradoxical insomnia should be considered in patients with insomnia who complain of severe insomnia, with little or no sleep but without objective evidence of consequences commensurate with the described level of sleep deprivation.
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• Patients show evidence of overestimation of sleep onset latency and underestimation of sleep efficiency.
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• Patients do not show other evidence of malingering or psychopathology.
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• Polysomnographic recordings do not show evidence of sleep disorder, and sleep parameters such as sleep efficiency and sleep onset latency are within normal limits.
Historical note and terminology
Sleep state misperception (paradoxical insomnia) is a diagnostic term adopted in the International Classification of Sleep Disorders (04) to replace 2 previously used diagnostic categories of sleep disorders: subjective insomnia complaint without objective findings and subjective sleepiness complaint without objective findings. In the ICSD-3 edition, the term sleep state misperception was replaced with “paradoxical insomnia” and will be used where appropriate herein (02). The American Academy of Sleep Medicine developed Research and Diagnostic Criteria (RDC) for insomnia (03). The RDC criteria also provided 3 subclassifications of primary insomnia: psychophysiologic insomnia, paradoxical insomnia, and idiopathic insomnia. Other terms used in the past to describe patients with this disorder include subjective insomnia, pseudo-insomnia, subjective sleepiness, and sleep hypochondriasis. Paradoxical insomnia implies a significant and persistent symptom, either insomnia or sleepiness, which is not documented on objective testing (nocturnal polysomnography and daytime multiple sleep latency test). Paradoxical insomnia is characterized by discrepancy between subjective and objective assessments of sleep measure and can be challenging to diagnose and to treat.
The ICSD-3 classifies paradoxical insomnia as a clinical and pathophysiological subtype of a chronic insomnia disorder, and symptoms must be present for at least 3 months.
A review of this concept of sleep state misperception addressed a different subset of individuals who seem to overestimate the amount of time spent in sleep compared to that captured on polysomnography. For extensive reviews, please see (32; 09).