Abstract Mkid 142

We conducted this study to assess the usefulness of polysomnography (PSG) in patients referred to the sleep disorders center (SDC) with chronic insomnia. Sixtyseven patients with chronic insomnia who underwent overnight polysomnography were included in the study. Clinical diagnoses were reported using the second revision of the International Classifications of Sleep Disorders (ICSD). The mean age of the studied group was 43±1.5 years and males comprised 53.7%. In the whole group, sleep onset latency was 42.6±7.74 minutes, sleep efficiency 69.9±2.5 and arousal index was 18.8±1.8 per hour. Presumptive polysomnographic diagnoses were identified in 56 patients (83.6%). Sleep state misperception (SSM) represented 40.3% of the studied insomniacs and sleep disordered breathing (SDB) was detected in 25.4%. The present study illustrated the importance of PSG in the assessment of selected patients with chronic insomnia. It also demonstrated that high percentage of insomniacs have subjective insomnia. Finally, the prevalence of SDB is common among patients with chronic insomnia. Further studies are needed to explore the relation between insomnia and SDB and to delineate the clinical significance of the so-called SSM.