Dream experience during REM and NREM sleep of patients with complex partial seizures.
Carlo Cipolli, Enrica Bonanni, Michelangelo Maestri, Michela Mazzetti, Luigi Murri
Brain Research Bulletin June 30, 2004 DOI: 10.1016/j.brainresbull.2003.12.014 (opens in new tab) via PubMed
Summary
AI-generated from the abstractPatients with complex partial seizures recall dreams less often after stage 2 NREM sleep than after REM sleep, regardless of which hemisphere the seizure focus is in. The length and structural organization of dreams do not differ significantly between REM and NREM sleep. However, during REM sleep, the length of story-like dreams is influenced by global cognitive functioning. These results suggest that the elaboration of dream experience is maintained in both sleep stages, but access to information for conversion into dream content and the consolidation of that content is less effective during NREM sleep. Further research may determine whether impaired memory functioning during NREM sleep is a side effect of anticonvulsant treatment.
Study at a glance
| Characteristics | Observational cohort Peer reviewed |
|---|---|
| Sample size | 12 |
| Population | Cognitively unimpaired patients with complex partial seizures (six with right hemisphere focus, six with left hemisphere focus) |
| Duration | Three consecutive nights (adaptation, polysomnography, dream collection) |
| Key finding | Dream recall is lower after stage 2 NREM sleep than after REM sleep in patients with complex partial seizures, while dream length and structure do not differ between sleep stages. |
Abstract
This study examined the effectiveness of the cognitive processes underlying dreaming in patients with complex partial seizures (CPS), by assessing the frequency of recall and the structural organization of dreams reported after awakenings provoked alternately during REM and stage 2 NREM sleep on 12 cognitively unimpaired CPS-patients (six with epileptic focus in the right hemisphere and six in the left one). Each patient was recorded for three consecutive nights, respectively, for adaptation to the sleep laboratory context, for polysomnography and for dream collection. The frequency of dream recall was lower after stage 2 NREM sleep than REM sleep, regardless of the side of epileptic focus, while the length and structural organization of dreams did not significantly differ in REM and NREM sleep. However, the length of story-like dreams was influenced by global cognitive functioning during REM sleep. These findings indicate that in CPSs-patients the elaboration of dream experience is maintained in both REM and NREM sleep, while the access to information for conversion into dream contents and the consolidation of dream contents is much less effective during NREM rather than during REM sleep. Further studies may distinguish between these two possibilities and enlighten us as to whether the impaired memory functioning during NREM sleep is a side effect of anticonvulsant treatment.