insomnia, are associated with activities of daily living levels in inpatients at rehabilitation units. Materials and methods: Eligible inpatients, enrolled retrospectively and consecutively, underwent measures of one-night polysomnography, soci- odemography, medical comorbidities, stroke characteristics, and Barthel Index (BI) scores. Results: Of 123 patients (61.6±13.1 years; 23.8±3.4 kg/m 2 ; 33% female; 90.5±36.7 days post-stroke; 46.7±25.1 events/h in apnea-hypopnea in- dex), 103 (92%) had moderate-to-severe SDB, and 24 (19.5%) had better continuous-positive-airway-pressure adherence. Diverse values were found for total sleep time (259±71 min), sleep efficiency (69.5±19.3%), sleep latency (24.3±30.9 min), and wakefulness after sleep onset (93.1±74.2 min). Admission and admission-discharge BI score changes were 33.8±23.2 and 10.1±9.2, respectively. National Institutes of Health Stroke Score (NIHSS, 10.2±5.6), available in 57 (46%) patients, negatively associated with admission levels and gains in BI scores (p< 0.001, ¼0.002, respectively) in a univariate analysis. In regression models with backward selection excluding NIHSS, age (p¼0.025) and wakefulness after sleep onset (p< 0.001) were both negatively associated (adjusted R 2 ¼0.260) with admission BI scores. Comorbidity of hypertension, sleep latency, percentage of stage one non-rapid-eye-movement sleep, and desaturation events4% (p: < 0.001, 0.001, 0.021, and 0.043, respectively; adjusted R 2 ¼0.252) were negatively associated with BI score gains. Conclusions: In addition to contributing polysomnography data essential for optimizing functional rehabilitation of subacute stroke patients, our data suggest that insomnia is likely a more influential factor than SDB for brain functional recovery. Neurological Sleep Disorders Affecting Sleep SLEEP IMPAIRMENTS IN PATIENTS OF FIBROMYALGIA V.K. Tiwari , M. Mirdha, H.N. Mallick, R. Bhatia, S. Jain, R. Sharma, U. Kumar. Physiology, All India Institute of Medical Sciences, New Delhi, India Introduction: Fibromyalgia patients frequently complain of less and fragmented sleep, resulting day time dysfunction (not feeling fresh after awakening in morning). Patients are having difficulty in falling sleep reportedly due to severe pain. Sleep is complimentary to antinociception. Sleep restored patients report with increase in pressure pain threshold. The present study is undertaken to study various sleep parameters in 30 fibromyalgia patients by using PSQI and ESS questionnaires. In the preliminary study we have recruited 7 fibromyalgia patients and 7 age and sex matched controls. We are including right-handed patients with above quoted age group and diagnosed (according to ACR-2010), as primary fibromyalgia and referred from Physical Medicine and Rehabili- tation and Rheumatology department. Fibromyalgia patients suffering from other chronic diseases (like other pain syndrome, major psychiatric disorders besides depression, autoim- mune disease, rheumatic disease) are excluded from the study. Materials and methods: Sleep parameters like sleep pattern latency, duration, habitual sleep efficiency, sleep disturbances and daytime dysfunction were assessed and determined by using a standardised and validated questionnaire like Pittsburg Sleep Quality Index (PSQI) and we also assessed sleepiness during various daily chores by Epworth Sleepiness Scale (ESS). Results: The followings trends are seen in the patients of fibromyalgia studied so far : ESS in fibromyalgia shows tendency of dozing mostly after lunch followed by sitting / reading also in sitting inactive during sitting, inactive in public places. More number of fibromyalgia patients showing global PSQI score are in the range of 7-9. Various sleep parameters like subjective sleep quality : score 2 which is fairly bad, sleep latency score: 3, sleep disturbances score : 2, sleep duration : 5-6 hours daily and Daytime dysfunction : score 2. Conclusions: Patients with fibromyalgia show poor scoring in Health- related Quality of Life (HRQoL) questionnaire due to pain which leads into gross sleep disturbance per se in terms of latency and duration. This sleep disruption further causes alteration in pain processing mechanism and vicious cycles ensues. Future directions : We will complete the study with committed number of fibromyalgia patients and later complete data will be statistically analysed for detailed discussion and results. We will also perform Polysomnography with patients with extreme scores and severe sleep impairments. Acknowledgements : Prof. H.N. Mallickfor his valuable inputs and Baldev Singh Laboratory for Sleep Research, Department of Physiology, All India Institute of Medical Sciences, Ansari Nagar, New Delhi, India. Sleep Breathing Disorders IS THE RESPIRATORY STABILITY DURING SLEEP IN PATIENTS WITH SEVERE HEART FAILURE INFLUENCED BY THE NOCTURNAL OXYGEN LEVEL? A SUB-ANALYSIS OF THE PROST STUDY USING A NOVEL RESPIRATORY STABILITY INDEX T. Tobushi 1 , S.-I. Ando 2 , J. Takagawa 3 , N. Kumagai 4 , T. Kadokami 1 , K. Dohi 4 , S. Joho 5 , O. Wada 6 , T. Koyama 7 , N. Haruki 8 , H. Asanoi 3 , S.-I. Momomura 9 . 1 Cardiovascular Medicine, Saiseikai Futsukaichi Hospital, Chikushino, Japan; 2 Sleep Apnea Center, Kyushu University Hospital, Fukuoka, Japan; 3 Cardiology Division, Imizu Municipal Hospital, Imizu, Japan; 4 Cardiology and Nephrology, Mie University Graduate School of Medicine, Tsu, Japan; 5 Second Department of Internal Medicine, University of Toyama, Toyama, Japan; 6 Internal Medicine, Japan Community Healthcare Organization Takaoka Fushiki Hospital, Takaoka, Japan; 7 Cardiovascular and Respiratory Medicine, Akita University Graduate School of Medicine, Akita, Japan; 8 Molecular Medicine and Therapeutics, University of Tottori, Yonago, Japan; 9 Cardiovascular Medicine, Jichi Medical University Saitama Medical Center, Saitama, Japan Introduction: Many patients with heart failure (HF) are accompanied by obstructive and/or central (known as Cheyne-Stokes respiration) sleep disordered breathing (SDB). Patients with HF also show irregular rapid and shallow respiration which is believed to be evoked by pulmonary congestion even while they are awake. As some of such unstable respira- tions appear at the state of worsening HF, respiratory instability could be a key indicator of alteration of the state of HF. For this purpose, we proposed a new index named Respiratory Stability Index (RSI) which was attained from the inverse number of the standard deviation of respiration fre- quency distribution. With this index, we underwent the PROST (pro- spective study on respiratory stability through recovery process from deterioration of HF) study, which was a multicenter (8 Japanese institutes), prospective, observational cohort study measuring alteration of RSI from acute decompensated period to fully recovered period in HF patients. We have already presented the first result that RSI significantly increased as the clinical status of heart failure, especially congestive condition, improved (Takagawa, Japanese Circulation Society meeting 2017). As respiration is strongly influenced by the oxygen level, we tried to further study whether the oxygen level also influences the instability of respira- tion in HF. Materials and methods: In PROST study, we enrolled 44 patients with acute decompensated HF. In the present subanalysis of PROST study, we analyzed 42 data sets in their deterioration period. Overnight RSI values were calculated from the respiration data collected using a portable polygraph (SAS-3200) and analyzed using custom made algorithm (Asa- noi, J Cardiol, 2017). We compared the overnight mean oxygen saturation (S P O 2 ) and the 3 % oxygen desaturation index (3%ODI) with RSI. Further- more, we evaluated the effect of oxygen inhalation on the relationship between these parameters and RSI values. Results: RSI values and mean S P O 2 values while the patients sleep during deterioration period were not significantly correlated (p¼0.32). This negative relationship was not affected by oxygen inhalation at the time of data collection (p¼0.38, 0.28, respectively). On the other hand, RSI values showed significantly correlation with 3%ODI (p¼0.0003) regardless oxy- gen inhalation (p¼0.04, 0.004, respectively). Conclusions: Respiratory instability in severe HF patients may not be the result of mean oxygen desaturation but mainly caused by congestive state of the lung. As 3%ODI indicates respiratory irregular- ity with a low frequency accompanied by oxygen desaturation, the significant correlation between 3%ODI and RSI may suggest that the rapid and shallow type irregular respiration might not be a sole cause of decrease in RSI but worsening of central type SDB during deteriorated period would constitute some part of RSI change. Thus, RSI may correctly reflect the pulmonary congestive state regardless of the level of oxygenation. Abstracts / Sleep Medicine 40 (2017) e186ee363 e328