OBJECTIVES: Sleep disorders cause changes of autonomic nervous system (ANS) which affect cardiovascular system. Primary insomnia (PI) makes acceleration of sympathetic nervous system (SNS) tone by sleep deficiency and arousal. Obstructive sleep apnea syndrome (OSAS) sets off SNS by frequent arousals and hypoxemias during sleep. We aimed to compare the changes of heart rate variability (HRV) indices induced by insomnia or sleep apnea to analyze for ANS how much to be affected by PI or OSAS. METHODS: Total 315 subjects carried out nocturnal polysomnography (NPSG) were categorized into 4 groups - PI, mild, moderate and severe OSAS. Severity of OSAS was determined by apnea-hypopnea index (AHI). Then we selected 110 subjects considering age, sex and valance of each group's size [Group 1 : PI (mean age=41.50+/-13.16 yrs, AHI <5, n=20), Group 2 : mild OSAS (mean age=43.67+/-12.11 yrs, AHI 5-15, n=30), Group 3 : moderate OSAS (mean age 44.93+/-12.38 yrs, AHI 16-30, n=30), Group 4 : severe OSAS (mean age=45.87+/-12.44 yrs, AHI >30, n=30)]. Comparison of HRV indices among the four groups was performed with ANCOVA (adjusted for age and body mass index) and Sidak post-hoc test. RESULTS: We found statistically significant differences in HRV indices between severe OSAS group and the other groups (PI, mild OSAS and moderate OSAS). And there were no significant differences in HRV indices among PI, mild and moderate OSAS group. In HRV indices of PI and severe OSAS group showing the most prominent difference in the group comparisons, average RR interval were 991.1+/-27.1 and 875.8+/-22.0 ms (p=0.016), standard deviation of NN interval (SDNN) was 85.4+/-6.6 and 112.8+/-5.4 ms (p=0.022), SDNN index was 57.5+/-5.2 and 87.6+/-4.2 (p<0.001), total power was 11,893.5+/-1,359.9 and 18,097.0+/-1,107.2 ms2 (p=0.008), very low frequency (VLF) was 7,534.8+/-1,120.1 and 11,883.8+/-912.0 ms2 (p=0.035), low frequency (LF) was 2,724.2+/-327.8 and 4,351.6+/-266.9 ms2 (p=0.003). CONCLUSIONS: VLF and LF which were correlated with SNS tone showed more increased differences between severe OSAS group and PI group than other group comparisons. We could suggest that severe OSAS group was more influential to increased SNS activity than PI group.
Acceleration ; Anoxia ; Arousal ; Autonomic Nervous System ; Cardiovascular System ; Heart ; Heart Rate ; Polysomnography ; Sleep Apnea Syndromes ; Sleep Apnea, Obstructive ; Sleep Wake Disorders ; Sleep Initiation and Maintenance Disorders ; Sympathetic Nervous System

BACKGROUND: Spinal cord ischemia initiates a deleterious cascade of biochemical events that ultimately result in an increased intracellular calcium concentration. Many papers have been published on this topic but without a clear consensus on the best way of minimizing the problem. For the further study of preventing neurological injury after spinal ischemia, the proper animal model is necessary. In this study we compared spinal ischemia time on neurologic and histopathologic outcome, and inflammatory gene expression in transient spinal ischemia. METHODS: Rats were anesthetized with halothane, and divided into 4 groups:12.5 minutes of spinal ischemia (Group 1), 15 minutes of spinal ischemia (Group 2), 17.5 minutes of spinal ischemia (Group 3), and 20 minutes of spinal ischemia (Group 4). Spinal ischemia was produced by both induced hypotension and thoracic aortic cross clamping. After spinal ischemia neurologic scores were assessed after 1, 3, 6, and 24 hours. After 24 hours, rats were euthanized and spinal cords were removed for histopathologic assessment and an assay of TNF-alpha and IL-1 mRNA. RESULTS: The neurologic scores worsened according to the ischemia time. The histopathologic scores correlated well with the neurologic scores. The TNF-alpha and IL-1 mRNA expression results of group 2 were larger than those of group 1. There were no significant differences between group 2, group 3, and group 4. CONCLUSIONS: Inflammatory gene expressions are increased during transient spinal ischemia. After 15 minutes of ischemia, no further increase of mRNA expression was shown. The 15 minutes of spinal ischemia was sufficient for the spinal ischemic study in rats.
Animals ; Calcium ; Consensus ; Constriction ; Gene Expression ; Halothane ; Hypotension ; Interleukin-1 ; Ischemia* ; Models, Animal ; Rats* ; RNA, Messenger* ; Spinal Cord ; Spinal Cord Ischemia ; Tumor Necrosis Factor-alpha

OBJECTIVES: This study was designed to assess the change of heart rate variability (HRV) at resting, upright, and psychological stress in anxiety disorder patients. METHODS: HRV was measured at resting, upright, and psychological stress states in 60 anxiety disorder patients. We used visual analogue scale (VAS) score to assess tension and stress severity. Beck depression inventory (BDI) and state trait anxiety inventories I and II (STAI-I and II) were used to assess depression and anxiety severity. Differences between HRV indices were evaluated using paired t-tests. Gender difference analysis was accomplished with ANCOVA. RESULTS: SDNN (Standard deviation of normal RR intervals) and low frequency/high frequency (LF/HF) were significantly increased, while NN50, pNN50, and normalized HF (nHF) were significantly decreased in the upright position compared to resting state (p < 0.01). SDNN, root mean square of the differences of successive normal to normal intervals, and LF/HF were significantly increased, while nHF was significantly decreased in the psychological stress state compared to resting state (p < 0.01). SDNN, NN50, pNN50 were significantly lower in upright position compared to psychological stress and nVLF, nLF, nHF, and LF/HF showed no significant differences between them. CONCLUSION: The LF/HF ratio was significantly increased after both physical and psychological stress in anxiety disorder, but did not show a significant difference between these two stresses. Significant differences of SDNN, NN50, and pNN50 without any differences of nVLF, nLF, nHF, and LF/HF between two stresses might suggest that frequency domain analysis is more specific than time domain analysis.
Anxiety ; Anxiety Disorders* ; Autonomic Nervous System ; Depression ; Equipment and Supplies ; Heart Rate* ; Humans ; Stress, Psychological*

OBJECTIVES: There are a lot of studies that analyze the interaction between the emotion of disgust and the functional brain images using fMRI and PET. But studies using sLORETA (standardized low resolution brain electromagnetic tomography) almost do not exist. The aim of this research is to explore the relationship of the emotion of disgust and the cortical activation using sLORETA analysis. METHODS: Forty five healthy young adults (27.1+/-2.6 years) participated in the study. While they were watching 4 neutral images and 4 disgusting images associated with mutilation selected from the international affective picture system (IAPS), participants' EEGs were taken for 30 seconds per one picture. Through these obtained EEG data, sLORETA analysis was performed to compare EEGs associated with neutral and negative images. RESULTS: During looking for visual disgusting stimulus, all participants reported unpleasantness, arousal and stress. In sLORETA analysis, the decrease of current density in theta wave was shown at left frontal superior gyrus (BA10) and middle gyrus (BA10, 11). This voxel cluster consists of a total of 11 voxels and the threshold of t value indicating statistically significant decreases in the current density (p<0.05) was -1.984. There were no differences between male and female in the degree of being disgusted by the stimuli. CONCLUSION: This finding may suggest that the activation of dorsolateral prefrontal cortex might be associated with regulating disgust emotion.
Arousal ; Brain ; Electroencephalography ; Female ; Humans ; Magnetic Resonance Imaging ; Magnets ; Male ; Prefrontal Cortex ; Young Adult

OBJECTIVES: It is well established that primary insomnia affects the activity of autonomic nervous system. We tried to know how the activity of autonomic nervous system during night sleep changes by analyzing correlation between heart rate variability (HRV) index and the variables related with sleep structure in primary insomnia. METHODS: Thirty three subjects (mean age:36.2+/-14.2 years, male:female=15:18) who were diagnosed with primary insomnia were selected for the study. Nocturnal polysomnography (NPSG) was carried out on each subject and correlation was analyzed between high frequency/low frequency ratio (LF/HF ratio), one of HRV indices and the variables related with sleep structure which were calculated from NPSG. RESULTS: When age and sex were controlled, LF/HF ratio showed negative correlations with slow wave sleep and stage 2 sleep, respectively (r(p)=-0.43, p=0.01;r(p)=-0.37, p=0.04). On the other hands LF/HF ratio showed a positive correlation with arousal index (r(p)=0.65, p<0.001). The activity of autonomic nervous system responded differentially depending on the change of sleep structure in primary insomnia. Especially the increase of arousal index and the decrease of slow wave sleep and stage 2 sleep which are the components of non-REM sleep provoked hyperactivity of sympathetic nervous system. CONCLUSION: This study suggests that the typical change of sleep structure in primary insomnia can negatively impact on cardiovascular system.
Arousal ; Autonomic Nervous System ; Cardiovascular System ; Hand ; Heart ; Heart Rate ; Polysomnography ; Sleep Initiation and Maintenance Disorders

BACKGROUND: Midazolam is often used as an anxiolytic premedication before surgery, but it is difficult and complex to assess its effect. This study evaluated the bispectral index as an objective indicator of midazolam premedication and the relation of cardiovascular response to anesthetic induction. METHODS: Forty patients (aged 20 to 60 and in ASA class I or II) to undergo simple elective surgery under general anesthesia entered the study. The patients were divided into the midazolam group (n = 20) that received midazolam (0.08 mg/kg IM) and glycopyrrolate (0.2 mg IM) premedication, and the control group (n = 20) that received glycopyrrolate (0.2 mg IM) only. Then, anesthetic induction (fentanyl 1 microgram/kg, propofol 2 mg/kg, succinylcholine 1 mg/kg) was done. The bispectral index of the electroencephalogram, blood pressure, and heart rate were measured under unanesthetized conditions, after fentanyl, propofol injection, and intubation. RESULTS: The bispectral index was significantly lower in the midazolam group as compared with the control group before anesthetic induction, after fentanyl injection, and intubation. Blood pressure was not significantly different in the two groups. Heart rate was significantly lower in the midazolam group compared with the control group before anesthetic induction and after fentanyl injection. CONCLUSIONS: Midazolam-premedicated patients appear to maintain stable hemodynamics during anesthetic induction and intubation. The bispectral index can be objectively used in midazolam-premedicated patients when evaluating the degree of sedation. (Korean J Anesthesiol 2000; 38: 947~953)
Anesthesia, General ; Blood Pressure ; Electroencephalography ; Fentanyl ; Glycopyrrolate ; Heart Rate ; Hemodynamics ; Humans ; Intubation ; Midazolam* ; Premedication* ; Propofol ; Succinylcholine

The present study compared the actigraphic indices between both wrist actigraphies (WATGs), and the sleep estimates between each WATG and nocturnal polysomnography (NPSG) to assess their differences and consistencies. We studied 22 right-handed subjects (mean age 43.9+/-13.3 years, M:F=14:8) with untreated primary sleep disorders (primary insomnia=8, simple snorer=2, obstructive sleep apnea=12) undergone by overnight both WATGs and NPSG, simultaneously. Comparison and correlation were analyzed between right and left wrist actigraphic data. In the sleep estimates of both WATGs and NPSG, each WATG was compared and correlated with NPSG in sleep period time (SPT), total sleep time (TST), sleep latency (SL), sleep efficiency (SE) and wake time (WT). Sleep indices between both WATGs showed significant positive correlations with no correlations in SL and fragmentation index (FI). There were no differences in sleep indices between both WATGs. SPTs of both WATGs, SL of left WATG, and TST of right WATG showed positively significant correlations, and SE of right WATG did negatively significant correlation in sleep indices between each WATG and NPSG. As each WATG was compared to PSG, SPTs of both WATGs and WT of right WATG were decreased, and TST and SE of right WATG and SL of left WATG were increased. Inconsistent SL and FI between both WATGs indicate that the activities between both WATGs can differentially happen during wake or arousal. Inconsistent sleep estimates between each WATG and NPSG may indicate the limited usefulness in measuring and analyzing one-night sleep by using WATG.
Arousal ; Functional Laterality ; Polysomnography* ; Sleep Wake Disorders ; Wrist*

OBJECTIVE: To investigate how differences in oxygen saturation between non-REM (NREM) and REM sleep in patients according to the severity of sleep apnea. METHODS: We studied 396 male patients diagnosed with simple snoring or obstructive sleep apnea syndrome (OSAS) on nocturnal polysomnography. Patients were divided into groups by the OSAS severity. We compared the average oxygen saturation between REM and NREM sleep in each group. RESULTS: In the simple snoring group, average oxygen saturation was significantly greater during REM than during NREM sleep. In the severe OSA group alone, average oxygen saturation was greater in NREM than in REM sleep. The difference of NREM-REM average oxygen saturation correlated significantly with AHI in the severe OSA group. CONCLUSION: More severe hypoxemia was seen in REM than NREM sleep in the severe OSAS group. The differential oxygen decrease between REM and NREM sleep is likely due to the differentially occurring sleep breathing events in each sleep stage according to the SDB severity. The more AHI increases in the severe OSAS patients, the more prominent the hypoxemia of REM sleep compared with NREM sleep is likely to appear. This suggests that the pressure of continuous positive airway pressure should be increased to control the hypoxemia of REM sleep in extremely severe OSAS.
Anoxia ; Continuous Positive Airway Pressure ; Eye Movements* ; Humans ; Male ; Oxygen* ; Polysomnography ; Respiration ; Sleep Apnea Syndromes* ; Sleep Apnea, Obstructive ; Sleep Stages ; Sleep, REM* ; Snoring

OBJECTIVES: A supine sleep position increases sleep apneas compared to non-supine positions in obstructive sleep apnea syndrome (OSAS). However, supine position time (SPT) is not highly associated with apnea-hypopnea index (AHI) in OSAS. We evaluated the correlation among sleep-related variables and SPT in OSAS. METHODS: A total of 365 men with OSAS were enrolled in this study. We analyzed how SPT was correlated with demographic data, sleep structure-related variables, OSAS-related variables and heart rate variability (HRV). Multiple linear regression analysis was conducted to investigate the factors that affected SPT. RESULTS: SPT had the most significant correlation with total sleep time (TST ; r = 0.443, p < 0.001), followed by sleep efficiency (SE ; r = 0.300, p < 0.001). Snoring time (r = 0.238, p < 0.001), time at < 90% SpO2 (r = 0.188, p < 0.001), apnea-hypopnea index (AHI ; r = 0.180, p = 0.001) and oxygen desaturation index (ODI ; r = 0.149, p = 0.004) were significantly correlated with SPT. Multiple regression analysis revealed that TST (t = 7.781, p < 0.001), snoring time (t = 3.794, p < 0.001), AHI (t = 3.768, p < 0.001) and NN50 count (t = 1.993, p = 0.047) were associated with SPT. CONCLUSION: SPT was more highly associated with sleep structure-related parameters than OSAS-related variables. SPT was correlated with TST, SE, AHI, snoring time and NN50 count. This suggests that SPT is likely to be determined by sleep structure, HRV and the severity of OSAS.
Heart Rate ; Humans ; Linear Models ; Male ; Oxygen ; Sleep Apnea Syndromes ; Sleep Apnea, Obstructive* ; Snoring ; Supine Position*

OBJECTIVE: A defense mechanism is an automatic psychological process necessary for successful adaptation. It reflects adaptive capacity. The purpose of this study is to explore the relationship between the adaptation ability of individuals who face mandatory military service and the pattern of defense mechanisms. METHODS: The subjects were 69 men (21.4±2.2 years) who expressed psychological difficulties in three military service situations. Control group was 36 men (24.0±1.4 years) who had successfully completed military service. We examined psychiatric history, the pattern of defense mechanisms, and depression and anxiety levels. Defense mechanisms were compared between two groups. RESULTS: The maladjusted group used immature defenses more frequently than the control group did. There were no differences in the defense patterns according to diagnosis. The control group used more identification and rationalization, classified as immature defenses. The temporarily maladjusted group used more somatization, regression, and avoidance. CONCLUSION: Using mature defense mechanisms helped young adults to adapt to a particular situation. The maturity of the defense is more valuable than the psychiatric diagnosis. Some immature defenses are also helpful to adapt. We cautiously assume that some defenses can be protective or risk factors in adapting to stressful situations by young adults.
Anxiety ; Defense Mechanisms ; Depression ; Diagnosis ; Humans ; Korea ; Male ; Mental Disorders ; Military Personnel ; Rationalization ; Risk Factors ; Social Adjustment ; Young Adult