Reverse sleep state misperception.

A 71-year-old woman with a 3-year history of excessive daytime sleepiness and an increased need for sleep did not feel restored upon awakening and had daytime fatigue despite a full night's sleep. She was evaluated with polysomnography (PSG). She significantly underestimated her sleep latency and awake time after sleep onset. The following morning, she stated that she had slept all night, when in fact she had extremely poor sleep efficiency and prolonged sleep latency. Another PSG and a two-week long actigraphy confirmed her misperception. Therefore, she perceived physiologic wakefulness, by PSG and actiraphy criteria, as subjective sleep, in direct contrast to 'conventional' sleep state misperception, in which patients usually present with a complaint of insomnia but have normal sleep quality and duration by PSG criteria. This patient may have a previously undescribed variation of sleep state misperception that the authors have tentatively named 'reverse' sleep state misperception.