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P0088 Compressed tracheal sound analysis as a screening method for obstructive apneas and hypopneas
Posters / Sleep Medicine 8 Suppl. 1 (2007) S69–S114 and in group 3: 78.1+10.2% vs 78.3+9.9%, p = 0.317). The presence of HT was not found to be related to RDI in either group. Multivariate logistic regression analysis revealed that nocturnal nadir oxygen desaturation level (p = 0.040), age (p < 0.001) and body mass index (p = 0.010) were the factors related with hypertension, while gender (p = 0.846), disease duration (p = 0.146) or RDI (p = 0.123) did not show significant relation with the presence of HT. Our results showed that the prevalance of HT increases with the increase in the severity of sleep-disordered breathing. On the other hand, from the pathophysiological point of view, not the RDI but the degree of nocturnal oxygen desaturation might play a role in HT in these patients. P0087 Restless legs syndrome (RLS) – unrecognized cause for insomnia and irritability in children I. Mohri1 *, K. Nishimura1 , N. Tachibana2 , M. Taniike1 . 1 Dept of Mental Health and Environmental Effects Research, The Research center for Child Mental Development, Osaka University Graduate School of Medicine, Osaka, Japan, 2 Human Brain Research Center, Kyoto University Graduate School of Medicine, Kyoto, Japan RLS has been gradually recognized as a cause for insomnia in adults, but there have been few reports about children with RLS in Japan. We describe four pediatric RLS cases [Case Reports]. Case 1: Six-year-old boy presented to our clinic with complaints of bad temper, having trouble getting to sleep. Home video showed he grasped his legs continuously when he was playing cards with his father before going to bed. Lab data revealed lower level of iron, microcytic anemia, and low ferritin (9 ng/ml). Iron was administered with no improvement, but pramipexole was effective to initiate sleep and the patient was no more irritated as before. Case 2: Six-year-old girl complained of discomfort in the legs, back, and neck at night. This feeling disturbed her sleep. Lab data showed low ferritin (35 ng/ml). After administration of iron with education of sleep hygiene, her symptoms were alleviated. Case 3: Four-year-old boy had been suffering from discomfort in the legs especially at bedtime for about 2 years. Lab data disclosed low ferritin (21 ng/ml). Administration of iron ameliorated his symptoms. Case 4: Four-year-old girl presented with leg discomfort at bedtime that started 9 months ago. Lab data revealed low ferritin (14 ng/ml). Her symptoms disappeared after iron was started. Discussion: All the parents of our cases had a hard time with their children because they were in a bad temper at bedtime. Two patients had clear family history and all patients showed low level of ferritin. Iron was effective in 3 cases, while pramipexole dramatically diminished RLS symptoms in the most severe case. RLS does occur in childhood and pediatricians should bear it in mind as one of the differential diagnosis when seeing children who are irritated and/or having difficulty initiating sleep. P0088 Compressed tracheal sound analysis as a screening method for obstructive apneas and hypopneas S.-L. Himanen1 *, E. Huupponen1 , A. Kulkas1 , E. Rauhala1,2 . 1 Department of Clinical Neurophysiology, Medical Imaging Centre, Pirkanmaa Hospital District, Tampere; 2 Department of Clinical Neurophysiology, Satakunta Central Hospital, Pori, Finland The aim of the present study was to examine the usability of compressed tracheal sound signal in the screening of obstructive apneas and hypopneas. Methods: Ten consecutive patients in our sleep laboratory volunteered to participate into the study. In addition to a conventional polysomnography, the tracheal sound signal from the neck was recorded with a small electret microphone. Embla N7000 and Somnologica software (Medcare, Iceland) were used as recording system. The sampling frequency for the sound signal was 11025 Hz and the raw data provided by the SuperHeLSA software was converted and synchronized into .ebm format using custom HeLSAEbm software. In order to visualize the sound we compressed the raw signal as follows: the maximum and minimum sound signal values of each consecutive 20 s epochs were taken.
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Results: In this compressed sound signal trace three different patterns were found: periods with flat signal curve close to zero, periods with thin signal curve deviating clearly from zero and periods with thick signal curve. From the compressed sound traces one episode (maximum 10 minute) of flat, thin and thick tracheal sound signal was selected from each subject, whenever present. Apnea/hypopnea index was calculated for each selected episode: Median AHI during thick sound curve was 72/h, whereas AHI during thin curve and flat curve was 0/h. In addition AHI was calculated for the whole night and the correlation coefficient between AHI and total time with thick sound signal curve was 0.827. Conclusions: The presented thick signal curve correlated well with the conventional apnea/hypopnea index of the polysomnography. The simple and fast screening method seems promising for future experimental and clinical sleep apnea studies. Contributed support: Supported by Tekes, the National Technology Agency of Finland and by grants from the Medical Research Fund of Tampere University Hospital. P0089 Characteristics of periodic leg movements in patients with Primary RLS during the first and second half of the night, hours of the night and in different stages of sleep S. Ismailogullari, M. Aksu. Neurology Department, Sleep Unit, Erciyes University Medical Faculty, Kayseri, Turkey The aim of this study was to analyze the periodic leg movements in patients with Primary Restless Legs Syndrome (RLS) and Periodic Limb Movements in Sleep (PLMS) during the first and second half of the night, hours of the night and in different stages of sleep and to determine the correlation between PLMS and sleep efficiency. The study has been performed with 15 untreated RLS patients also had PLMI score more than five. RLS diagnosis was based on the established criteria. Statistical analysis was performed by means of Friedman test to analyze the difference between hours and stages of sleep and Wilcoxon t test to compare the PLMI difference in the second and first half of the night. The correlation between PLMS and sleep efficiency was determined by Spearman’s correlation analysis. There was no difference between the first and second half of the night and sleep stages (p > 0.05). The PLMI in the first hour of the sleep was found more than the PLMI in the sixth, seventh and eighth hour of sleep (p < 0.05). The PLMI in the forth hour of sleep was more than sixth and seventh hour of sleep (p < 0.05). However there was no correlation between the PLMI and sleep efficiency. Since any significant PLMI difference was not found between the first and second half of the night, split night polysomnography study can be used in RLS+PLMS patients. The presence of a significant number of PLMS during REM sleep suggests that spinal motor inhibition is decreased in RLS patients. The reduced sleep efficiency in RLS patients was not found correlated with PLMI. That means that the reduced sleep efficiency in RLS patients is due to both sensorial and motor symptoms of RLS and PLMS is not enough to analyze of RLS severity alone. P0090 Possible connection with thin signal curve in compressed tracheal sound analysis and flow limitation pattern in children O. Saarenp¨aa¨ -Heikkil¨a1 , A.-M. Lapinlampi2 , S.-L. Himanen2 . 1 Pediatric Clinics, Tampere University Hospital, Tampere, Finland, 2 Department of Clinical Neurophysiology, Medical Imaging Centre, Pirkanmaa Hospital District, Tampere, Finland Aim: This pilot case report describes a possible connection between a novel nocturnal tracheal sound analysis and flow limitation pattern in polysomnography. Methods: Five children, aged 7 years, two girls and three boys have been studied so far. The study is approved in the ethical committee of the hospital. In addition to a conventional polysomnography, the tracheal sound signal from the neck was recorded with a small electret microphone. The sampling frequency for the sound signal was 11,025 Hz and the raw data provided by the SuperHeLSA software was converted and synchronized into .ebm format using custom HeLSAEbm software. Previously described
S91
Results: In this compressed sound signal trace three different patterns were found: periods with flat signal curve close to zero, periods with thin signal curve deviating clearly from zero and periods with thick signal curve. From the compressed sound traces one episode (maximum 10 minute) of flat, thin and thick tracheal sound signal was selected from each subject, whenever present. Apnea/hypopnea index was calculated for each selected episode: Median AHI during thick sound curve was 72/h, whereas AHI during thin curve and flat curve was 0/h. In addition AHI was calculated for the whole night and the correlation coefficient between AHI and total time with thick sound signal curve was 0.827. Conclusions: The presented thick signal curve correlated well with the conventional apnea/hypopnea index of the polysomnography. The simple and fast screening method seems promising for future experimental and clinical sleep apnea studies. Contributed support: Supported by Tekes, the National Technology Agency of Finland and by grants from the Medical Research Fund of Tampere University Hospital. P0089 Characteristics of periodic leg movements in patients with Primary RLS during the first and second half of the night, hours of the night and in different stages of sleep S. Ismailogullari, M. Aksu. Neurology Department, Sleep Unit, Erciyes University Medical Faculty, Kayseri, Turkey The aim of this study was to analyze the periodic leg movements in patients with Primary Restless Legs Syndrome (RLS) and Periodic Limb Movements in Sleep (PLMS) during the first and second half of the night, hours of the night and in different stages of sleep and to determine the correlation between PLMS and sleep efficiency. The study has been performed with 15 untreated RLS patients also had PLMI score more than five. RLS diagnosis was based on the established criteria. Statistical analysis was performed by means of Friedman test to analyze the difference between hours and stages of sleep and Wilcoxon t test to compare the PLMI difference in the second and first half of the night. The correlation between PLMS and sleep efficiency was determined by Spearman’s correlation analysis. There was no difference between the first and second half of the night and sleep stages (p > 0.05). The PLMI in the first hour of the sleep was found more than the PLMI in the sixth, seventh and eighth hour of sleep (p < 0.05). The PLMI in the forth hour of sleep was more than sixth and seventh hour of sleep (p < 0.05). However there was no correlation between the PLMI and sleep efficiency. Since any significant PLMI difference was not found between the first and second half of the night, split night polysomnography study can be used in RLS+PLMS patients. The presence of a significant number of PLMS during REM sleep suggests that spinal motor inhibition is decreased in RLS patients. The reduced sleep efficiency in RLS patients was not found correlated with PLMI. That means that the reduced sleep efficiency in RLS patients is due to both sensorial and motor symptoms of RLS and PLMS is not enough to analyze of RLS severity alone. P0090 Possible connection with thin signal curve in compressed tracheal sound analysis and flow limitation pattern in children O. Saarenp¨aa¨ -Heikkil¨a1 , A.-M. Lapinlampi2 , S.-L. Himanen2 . 1 Pediatric Clinics, Tampere University Hospital, Tampere, Finland, 2 Department of Clinical Neurophysiology, Medical Imaging Centre, Pirkanmaa Hospital District, Tampere, Finland Aim: This pilot case report describes a possible connection between a novel nocturnal tracheal sound analysis and flow limitation pattern in polysomnography. Methods: Five children, aged 7 years, two girls and three boys have been studied so far. The study is approved in the ethical committee of the hospital. In addition to a conventional polysomnography, the tracheal sound signal from the neck was recorded with a small electret microphone. The sampling frequency for the sound signal was 11,025 Hz and the raw data provided by the SuperHeLSA software was converted and synchronized into .ebm format using custom HeLSAEbm software. Previously described