Paradoxical insomnia (sleep mis-perception)

Anthony is a 55-year-old teacher who reports a history of difficulty initiating and maintaining sleep of more than 20 years duration. Symptoms have been fluctuating in time but over the last 12 months the insomnia has become significant enough to interfere with his daytime teaching. He reports a decrease in the ability to concentrate and some mood changes that have been of concern to him.

Anthony is a smoker of about 20 cigarettes a day and is on no caffeinated beverages. He has a history of heart burn but he is on no regular medication. Anthony divorced about 5 years ago and over the last 2 years has had a few relationships that only lasted a few months each time.

He described going to bed between 11pm-midnight. It would take at least 2 hours to fall asleep but he reported at least 2-3 times a week he would not sleep at all. He would eventually get up between 7.30-9am depending on the day of the week and would feel exhausted. He does not take naps through the day. Although he feels tired and foggy he does not fall asleep in unusual circumstances. More specifically he is not drowsy driving, visiting people, at the table or talking to people. Although he has felt tired while teaching he has never fallen asleep or felt drowsy in class.

On examination he denies having a depressed mood. The K10 (Kessler Psychological Distress Scale) showed mild anxiety. He appears to be over concerned about the effect of lack of sleep on his immune system and his health. He was worried of the lack of sleep affecting his job as a teacher.

Anthony underwent an actigraphy which is a small watch-like instrument worn on the non-dominant arm over a period of 1 to 2 weeks. This instrument gives us an indirect view of the person’s sleep and wake routine. The actigraphy showed a fairly regular rest and activity pattern usually going to bed about midnight and getting up around 7.30am. However, Paul was convinced that during the period of sleep shown by the actigraphy he was actually lying in bed not moving but fully alert.

The finding on the actigraphy as well as the dramatic degree of symptoms (not sleeping at all 2-3 times/week), together with the lack of any daytime sleepiness in this case is strongly suggestive of paradoxical insomnia (subjective insomnia). With that in mind a full overnight sleep study with EEG (electro-encephalogram) monitoring was performed. In the morning Paul felt that his sleep was as usual with perhaps no more than 1 hour of sleep through the night. The sleep study showed that the patient fell asleep within 20 minutes of turning the lights off and that he slept for 7 hours and 30 minutes out of 8 hours and 20 minutes of recording.

This is diagnostic of sleep misperception. In this condition there is a significant discrepancy between how the person perceives sleep compared to objective measure of sleep by brain wave activity.

Sleep misperception (paradoxical insomnia) is a poorly understood condition that is also difficult to treat. More recent investigations looking in detail at the structure of brain wave activity suggest that the person with paradoxical insomnia has some ‘awake wave’ overriding sleep. It is hypothesized that this may lead to “sleep without resting” and this explains the sensation of not having slept at all on waking up in the morning. In this situation however, because sleep has actually occurred the person is not sleepy during the day even though they feel not well functioning.

Treatment of this condition is difficult. The first step was to explain to Paul that he was actually getting enough sleep. This tends to re-assure the person that health is not at risk. On occasion the use of anti-anxiety medication such as benzodiazepine (“Valium™” like medication) can be beneficial in changing the perception of sleep. However the response to treatment is usually limited. It was important for Paul to realize that although his perception of sleep was poor, he actually got sufficient sleep and that was reassuring in terms of the potential risks associated with lack of sleep.