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Melatonin suppression by light
24P
Society Proceedings
fication Committee of the International Headache Society, 1988. The EEG was abnormal in 12% of migraine patients and in 11% of other patients. There was no difference between migraine and other forms of headache, Also, the proportion of abnormal records was not affected by age and the proportion of abnormal records is about the same as in control children in various publications. So there are no abnormalities in interictal EEG due to migraine or other headache and the EEG does not help in the classification of headaches in paediatric patients. Its only indication is differential diagnosis to diseases that usually are associated with EEG abnormalities, like epilepsy. 5.
The reproducibility of overnight recordings in sleep apnoea. J. Lojander, T. Salmi and P. Maasilta (Helsinki University Hospital, Helsinki)
The overnight recording of oximetry and breathing pattern is frequently used in diagnosis and screening of sleep apnoea syndrome (OSAS). We have assessed the reproducibility of overnight polygraphic recordings with oximetty (SaOT), the static charge sensitive bed (respiratory and body movements), thermistors (air-flow) and body position sensor. In 46 patients with clinical suspicion of OSAS the recording was repeated 1-22 weeks (median 16) after the initial study. Patients with both low and high number of apnoeas were selected for the second recording. No treatment and no changes in patient characteristics (e.g. weight) was allowed. We calculated the number of desaturation events (>4% 0D14, >lO% ODHO), mean nadir SaO2, time spent with SaO2 ~90% and the number of body movements for the time in bed. Significant (P < 0.001) correlation between repeated recordings were found for 0D14 (r = 0.83), time spend at SaO2 ~90% (r = 0.84) and the mean nadir SaO2 (r= 0.79). Correlation for 0D14 supine (r = 0.59) and the time spent supine (r = 0.60) was moderate. In 4 patients with position-dependent apnoeas there was clinically significant differences between the nights because of the difference in time spent supine. The combination of oximetry, thermistors, movement recording (SCSB) and body position sensor thus has a clinically sufficient reproducibility in the evaluation of OSAS. 6.
Non-invasive sleep-wake staging in infants and young children: SCSB versus PSG. - T. Kirjavainen, D. Cooper, 0. Polo and C.E. Sullivan (Department of Medicine, University of Sydney, Sydney)
We compared conventional polysomnographic (PSG) sleep staging to sleep staging based on a static-charge-sensitive bed (SCSB) recording in infants and young children. The study consisted of whole-night clinical sleep studies in 22 children at 24 weeks of age (SD 24, range l-79). With both methods rapid eye movement (REM) sleep, non-rapid eye movement (NREM) sleep and wakefulness were distinguished. The average inter-scorer reliability of the PSG sleep staging controlled in nine subjects was 88%. The average concordance between the two methods ranged from 82 to 8546, depending on the criteria used for scoring the SCSB. The mean sensitivity of the SCSB to detect NREM sleep ranged from 77 to 90% and to detect REM sleep from 61 to 86%. The mean specificity was 81-94% for NREM sleep and 84-94% for REM sleep. In conclusion, REM sleep is characterized by irregular breathing with fast respiratory movements. These changes are specific enough to allow distinction between episodes of NREM sleep, REM sleep and wakefulness with the non-invasive SCSB method in infants and young children. When combined with PSG, the SCSB enables better monitoring of the behavioral state of the child, which is not otherwise well predictable from PSG. 7.
Does sleep bruxism serve a physiological purpose? - T. Sjiiholm, 0. Polo, J. Mllntyvaara, J. Tanner, J. Piha and I. Lehtinen (Department of Physiology, University of Turku, Turku)
Our previous study of the non-invasive cardiovascular reflex tests (Valsalva manoeuvre, deep breathing test, and standing up) suggested that excessive bruxism is accompanied by abnormalities in sympathetic vasoconstrictor function. We hypothesized that rhythmic masticatory muscle activity is an autonomic reflex that supports cerebral blood supply. To test our hypothesis, rhythmic jaw movement activity was measured at baseline, after total sleep deprivation and after propranolol, aj3-adrenergic receptor blocker. The total sleep deprivation was used to decrease nocturnal motor activity in a non-specilic manner, whereas propranolol was given to reduce sympathetic activity. Three all-night polysomnographic recordings with bilateral masseter muscle EMG recordings were performed on a 24 year old female, who presented with a history of severe teethgrinding. Sleep deprivation decreased the masseter contraction (MC) index by 61% and propranolol by 72% when compared to the level of the baseline night. These observations are in line with our hypothesis suggesting a link between autonomic regulation of circulation and rhythmic activation of masticatory muscles. It is possible that bruxism has a physiological function which also operates in non-symptomatic subjects. 8.
Interview study of excessive daytime sleepiness in schoolchildren. - 0. Saarenpiill-Heikkilll (Medical School, University of Tampere, Tampere)
The aim of the present study was to find out the factors connected to excessive daytime sleepiness (EDS) and its chronic&y in adolescents. Participants were 107 schoolchildren (age range 13-19 years) with EDS (Group 1) and the same number without EDS (Group 2). Both groups were selected from our questionnaire study made 3 years earlier (n = 574) in which EDS was defined as daytime sleepiness occurring always or often. The same groups had also filled a follow-up questionnaire 1 year before the interview. In the interview data was collected with semi-structured questions. Information included data of sleep habits, disorders, daytime sleepiness pattern, illness, medication, depressive emotions and living habits. Somatic status was also examined. Logistic regression and log linear model were used as statistical tools. One hundred and thirty (61%) pupils took part in the interview. Sixty-six of them were from Group 1 and 64 from Group 2. Them were 20 (3.5%) pupils who had EDS in the questionnaire studies and in the interview. In the interview EDS was found to be connected to excessive sleep disorders (dreaming, snoring, night waking and difficulty in getting to sleep), frequent medication and frequent depressive emotions (log linear modelling). The chronicity of EDS was connected to tiequent sleep disorders, frequent smoking and medication (logistic regression). 9.
Melatonin suppression by light. - T. Partonen, 0. Vakkurl and J. Lunnqvist (National Public Health Institute, Helsinki)
Our objective was to test whether abnormal suppression of melatonin secretion would be a trait marker of seasonal affective disorder. For each test on 11 drug-free outpatients and 10 healthy controls, samples of saliva were taken simultaneously with the ratings of subjective sleepiness with the Stanford Sleepiness Scale and with the 1OOmm Visual Analogue Scale at 2200 and 2300 h. The subjects were exposed to light of 3300 lux for 5 min at 2200 h on the first evening and for 1 h at 2200 h on the second, and thereafter treated with the same light for 30 min for 14 successive evenings. There was no significant difference in the suppression of melatonin levels in saliva in response to the light tests between the patients and the controls in winter or summer. The first light test reduced significantly mom the level of subjective sleepiness in the patients than in controls. This reduction was not associated with the change in melatonin secretion. Neither measure was associated with the clinical improvement. We suggest that the antidepressive effect of light is not associated with excessive sensitivity to light.
Society Proceedings
fication Committee of the International Headache Society, 1988. The EEG was abnormal in 12% of migraine patients and in 11% of other patients. There was no difference between migraine and other forms of headache, Also, the proportion of abnormal records was not affected by age and the proportion of abnormal records is about the same as in control children in various publications. So there are no abnormalities in interictal EEG due to migraine or other headache and the EEG does not help in the classification of headaches in paediatric patients. Its only indication is differential diagnosis to diseases that usually are associated with EEG abnormalities, like epilepsy. 5.
The reproducibility of overnight recordings in sleep apnoea. J. Lojander, T. Salmi and P. Maasilta (Helsinki University Hospital, Helsinki)
The overnight recording of oximetry and breathing pattern is frequently used in diagnosis and screening of sleep apnoea syndrome (OSAS). We have assessed the reproducibility of overnight polygraphic recordings with oximetty (SaOT), the static charge sensitive bed (respiratory and body movements), thermistors (air-flow) and body position sensor. In 46 patients with clinical suspicion of OSAS the recording was repeated 1-22 weeks (median 16) after the initial study. Patients with both low and high number of apnoeas were selected for the second recording. No treatment and no changes in patient characteristics (e.g. weight) was allowed. We calculated the number of desaturation events (>4% 0D14, >lO% ODHO), mean nadir SaO2, time spent with SaO2 ~90% and the number of body movements for the time in bed. Significant (P < 0.001) correlation between repeated recordings were found for 0D14 (r = 0.83), time spend at SaO2 ~90% (r = 0.84) and the mean nadir SaO2 (r= 0.79). Correlation for 0D14 supine (r = 0.59) and the time spent supine (r = 0.60) was moderate. In 4 patients with position-dependent apnoeas there was clinically significant differences between the nights because of the difference in time spent supine. The combination of oximetry, thermistors, movement recording (SCSB) and body position sensor thus has a clinically sufficient reproducibility in the evaluation of OSAS. 6.
Non-invasive sleep-wake staging in infants and young children: SCSB versus PSG. - T. Kirjavainen, D. Cooper, 0. Polo and C.E. Sullivan (Department of Medicine, University of Sydney, Sydney)
We compared conventional polysomnographic (PSG) sleep staging to sleep staging based on a static-charge-sensitive bed (SCSB) recording in infants and young children. The study consisted of whole-night clinical sleep studies in 22 children at 24 weeks of age (SD 24, range l-79). With both methods rapid eye movement (REM) sleep, non-rapid eye movement (NREM) sleep and wakefulness were distinguished. The average inter-scorer reliability of the PSG sleep staging controlled in nine subjects was 88%. The average concordance between the two methods ranged from 82 to 8546, depending on the criteria used for scoring the SCSB. The mean sensitivity of the SCSB to detect NREM sleep ranged from 77 to 90% and to detect REM sleep from 61 to 86%. The mean specificity was 81-94% for NREM sleep and 84-94% for REM sleep. In conclusion, REM sleep is characterized by irregular breathing with fast respiratory movements. These changes are specific enough to allow distinction between episodes of NREM sleep, REM sleep and wakefulness with the non-invasive SCSB method in infants and young children. When combined with PSG, the SCSB enables better monitoring of the behavioral state of the child, which is not otherwise well predictable from PSG. 7.
Does sleep bruxism serve a physiological purpose? - T. Sjiiholm, 0. Polo, J. Mllntyvaara, J. Tanner, J. Piha and I. Lehtinen (Department of Physiology, University of Turku, Turku)
Our previous study of the non-invasive cardiovascular reflex tests (Valsalva manoeuvre, deep breathing test, and standing up) suggested that excessive bruxism is accompanied by abnormalities in sympathetic vasoconstrictor function. We hypothesized that rhythmic masticatory muscle activity is an autonomic reflex that supports cerebral blood supply. To test our hypothesis, rhythmic jaw movement activity was measured at baseline, after total sleep deprivation and after propranolol, aj3-adrenergic receptor blocker. The total sleep deprivation was used to decrease nocturnal motor activity in a non-specilic manner, whereas propranolol was given to reduce sympathetic activity. Three all-night polysomnographic recordings with bilateral masseter muscle EMG recordings were performed on a 24 year old female, who presented with a history of severe teethgrinding. Sleep deprivation decreased the masseter contraction (MC) index by 61% and propranolol by 72% when compared to the level of the baseline night. These observations are in line with our hypothesis suggesting a link between autonomic regulation of circulation and rhythmic activation of masticatory muscles. It is possible that bruxism has a physiological function which also operates in non-symptomatic subjects. 8.
Interview study of excessive daytime sleepiness in schoolchildren. - 0. Saarenpiill-Heikkilll (Medical School, University of Tampere, Tampere)
The aim of the present study was to find out the factors connected to excessive daytime sleepiness (EDS) and its chronic&y in adolescents. Participants were 107 schoolchildren (age range 13-19 years) with EDS (Group 1) and the same number without EDS (Group 2). Both groups were selected from our questionnaire study made 3 years earlier (n = 574) in which EDS was defined as daytime sleepiness occurring always or often. The same groups had also filled a follow-up questionnaire 1 year before the interview. In the interview data was collected with semi-structured questions. Information included data of sleep habits, disorders, daytime sleepiness pattern, illness, medication, depressive emotions and living habits. Somatic status was also examined. Logistic regression and log linear model were used as statistical tools. One hundred and thirty (61%) pupils took part in the interview. Sixty-six of them were from Group 1 and 64 from Group 2. Them were 20 (3.5%) pupils who had EDS in the questionnaire studies and in the interview. In the interview EDS was found to be connected to excessive sleep disorders (dreaming, snoring, night waking and difficulty in getting to sleep), frequent medication and frequent depressive emotions (log linear modelling). The chronicity of EDS was connected to tiequent sleep disorders, frequent smoking and medication (logistic regression). 9.
Melatonin suppression by light. - T. Partonen, 0. Vakkurl and J. Lunnqvist (National Public Health Institute, Helsinki)
Our objective was to test whether abnormal suppression of melatonin secretion would be a trait marker of seasonal affective disorder. For each test on 11 drug-free outpatients and 10 healthy controls, samples of saliva were taken simultaneously with the ratings of subjective sleepiness with the Stanford Sleepiness Scale and with the 1OOmm Visual Analogue Scale at 2200 and 2300 h. The subjects were exposed to light of 3300 lux for 5 min at 2200 h on the first evening and for 1 h at 2200 h on the second, and thereafter treated with the same light for 30 min for 14 successive evenings. There was no significant difference in the suppression of melatonin levels in saliva in response to the light tests between the patients and the controls in winter or summer. The first light test reduced significantly mom the level of subjective sleepiness in the patients than in controls. This reduction was not associated with the change in melatonin secretion. Neither measure was associated with the clinical improvement. We suggest that the antidepressive effect of light is not associated with excessive sensitivity to light.