Le sommeil des personnes atteintes de schizophrénie : résultats d’études par questionnaire, polysomnographie et analyse spectrale de l’EEG en sommeil paradoxal

Patients with schizophrenia may have an abnormal sleep even when clinically stable under pharmacological treatments. In the present thesis, sleep studies aim at measuring central nervous system dysfunctions that can be involved in the pathophysiology of schizophrenia. The present thesis includes three studies. These studies report results on sleep in patients with schizophrenia in a three levels analysis with three different groups of patients. The first level is subjective and describes sleep habits using a questionnaire administered to outpatients with schizophrenia clinically stable under pharmacological treatments. The second level of analysis is objective and evaluates sleep architecture using a meta-analysis of polysomnographic studies in untreated patients with schizophrenia. The third level is microstructural and uses electroencephalogram (EEG) spectral analysis to characterize REM sleep in never-treated patients with first-episode schizophrenia. The first study shows that, when evaluated using a sleep habits questionnaire, outpatients with schizophrenia clinically stable under pharmacological treatments report increased time to fall asleep, have earlier bedtime, later risetime, spend more time in bed and do more naps compared to healthy participants. Also, similarly to healthy participants, most patients with schizophrenia report normal wake time after sleep onset, are normally satisfied about their sleep and feel normally refreshed in the morning. The second study reveals that, objectively, when polysomnographic studies evaluating untreated patients with schizophrenia are submitted to a meta-analysis, patients with schizophrenia have increased sleep latency, reduced total sleep time, reduced sleep efficiency and increased wake time after sleep onset compared to healthy participants. Patients in acute drug withdrawal show more severe sleep disturbances in these variables compared to never treated patients. Only never treated patients show decreased stage 2 sleep duration compared to healthy participants. The meta-analysis does not reveal significant differences between groups in regards to slow wave sleep and paradoxical sleep variables. The third study about REM sleep EEG spectral analysis shows decreased relative alpha spectral amplitude in frontal, central and temporal cortical regions and increased relative beta2 spectral amplitude in the occipital region in never treated patients with first-episode schizophrenia compared to healthy participants. Absolute alpha spectral amplitude correlates positively with negative symptoms in the frontal, central and temporal regions and negatively with positive symptoms in the occipital region. No significant correlation has been observed between beta2 spectral amplitude and clinical symptoms of schizophrenia. These results are discussed following the possibility that dysfunctions in the mechanisms of vigilance would be involved in the pathophysiology of schizophrenia.

Keyphrases: hypersomnie, insomnie, psychiatrie, schizophrène, vigilance, Arousal, electroencephalogram, hypersomnia, insomnia, meta-analysis, physiopathology, psychiatry, psychotic disorder, schizophrenia