Three patients with non-REM parasomnias experienced episodes of Cotard delusion—believing they were dead or dying and unable to perceive their bodies as their own. These nihilistic mentations occurred during confusional arousals from sleep and were accompanied by panic. EEG source analysis indicated right-hemispheric hypoactivity during the episodes. The authors argue that aberrant activation of the salience network and default mode network—two major intrinsic networks of wakefulness—underlies these states. Such dreamlike mentations are rarely remembered and likely underreported, but can cause significant distress and worsen clinical outcomes if unaddressed.
A 7-year history of vivid, immersive dreaming perceived as continuous with waking life, accompanied by persistent dream-reality confusion, is described in a younger individual. The patient engaged in reality-testing behaviors and reported significant cognitive fatigue. Video-polysomnography confirmed REM sleep without atonia and a dream re-enactment episode. Neuropsychiatric evaluation ruled out dissociative or psychotic disorders, and no neurodegenerative disease was observed. The case suggests a potentially distinct, non-neurodegenerative REM parasomnia phenotype, highlighting the need to expand current classifications to capture cognitive and metacognitive dimensions of REM sleep disorders. Potential mechanisms involving melanin-concentrating hormone signaling are discussed.