Search results for "polysomnography"
showing 10 items of 133 documents
Autonomic cardiac regulation in obstructive sleep apnea syndrome: evidence from spontaneous baroreflex analysis during sleep
1997
Objective. To assess spontaneous baroreceptor-heart rate reflex sensitivity during sleep in patients with obstructive sleep apnea syndrome, a condition associated with increased cardiovascular morbidity and mortality and characterized by marked sympathetic activation, which is believed to originate from hypoxic chemoreceptor stimulation, although little is known of other possible mechanisms such as baroreflex impairment. Design and methods. In 11 patients with severe obstructive sleep apnea syndrome (mean ± SD age 46.8 ± 8.1 years, apnea/hypopnea index 67.9 ± 19.1 h), who were normotensive or borderline hypertensive during wakefulness by clinic blood pressure measurements, finger blood pres…
Electrophysiological brainstem investigations in obstructive sleep apnoea syndrome.
1996
Phasic inspiratory genioglossus activity prevents pharyngeal airway collapse in healthy subjects during sleep and is diminished or absent in obstructive sleep apnoea syndrome (OSAS), thus leading to pharyngeal obstruction. Case reports of OSAS after pontomedullary lesions indicate that impaired inspiratory genioglossal activity may result from brainstem lesions. We therefore investigated brainstem functions in 18 awake patients with OSAS using brainstem auditory evoked potentials, blink reflex, masseter reflex, masseter inhibitory reflex (in 11 of 18 patients), magnetic evoked potentials of the tongue and electrooculography with vestibular testing. Fifteen of 18 patients showed no electroph…
Effects of yohimbine on sexual experiences and nocturnal penile tumescence and rigidity in erectile dysfunction.
1996
The therapeutic effect of the alpha 2-antagonist yohimbine in erectile dysfunction was studied in a double-blind placebo-controlled design. Thirty-one male patients underwent extensive clinical, urological, and psychiatric diagnosis and were dichotomically classified into an organic and a nonorganic subgroup. Following a 1-week placebo run-in period, patients were randomly assigned to a placebo or a verum group (yohimbine 15 mg daily) for a treatment period of 7 weeks. The Clinical Global Impression (CGI) scale was used as the primary efficacy parameter. Additionally, nocturnal penile tumescence and rigidity (NPTR) were measured. Global assessment of erectile function applying the CGI scale…
Polysomnography and ApneaGraph in patients with sleep-related breathing disorders.
2007
<i>Purpose:</i> To evaluate whether ApneaGraph (AG) and polysomnography (PSG) deliver comparable results in patients with sleep-related breathing disorders. <i>Procedures:</i> A prospective study was performed, which included 14 patients with obstructive sleep apnea syndrome. Apnea-hypopnea index (AHI), hypopnea index (HI), apnea index (AI), obstructive, central and mixed apnea, oxygen saturation (SaO<sub>2</sub>), pulse and body position were simultaneously assessed by PSG and AG in each individual. <i>Results:</i> There was a good correlation between measurements of AG and PSG for AHI, pulse, SaO<sub>2</sub>, body position and ce…
Estimation of the dimensionality of sleep-EEG data in schizophrenics
1993
Deterministic chaos could be regarded as a healthy flexibility of the human brain necessary for correct neuronal operations. Several investigations have demonstrated that in healthy subjects the dimensionality of REM sleep is much higher than that of slow wave sleep (SWS). We investigated the sleep-EEG of schizophrenic patients with methods from nonlinear system theory in order to estimate the dynamic properties of CNS. We hypothesized that schizophrenics would reveal alterations of their dynamic EEG features indicating impaired information processing. In 11 schizophrenic patients, the EEG's dimensionality during sleep stages II and REM was reduced. We suggest that such lower dimensional ch…
An analysis of the brain's transfer properties in schizophrenia: Amplitude frequency characteristics and evoked potentials during sleep
1998
Background: Classical analysis of spontaneous sleep electroencephalogram (EEG) in schizophrenia commonly reveals alterations of sleep continuity, number of awakenings, slow-wave sleep (SWS), and REM sleep compared to healthy controls; however, conventional analysis cannot help understand dynamic differences of the sleep EEG during different sleep stages. Methods: We measured late components of auditory evoked potentials (AEPs) and visual evoked potentials (VEPs) during different sleep stages of 11 schizophrenic inpatients and in a sex- and age-matched control group from scalp positions FZ, CZ, and PZ. According to linear system theory, we then computed the amplitude-frequency characteristic…
Diabetes mellitus prevalence and control in sleep-disordered breathing: The European Sleep Apnea Cohort (ESADA) study
2014
BACKGROUND: OSA is associated with an increased risk of cardiovascular morbidity. A driver of this is metabolic dysfunction and in particular type 2 diabetes mellitus (T2DM). Prior studies identifying a link between OSA and T2DM have excluded subjects with undiagnosed T2DM, and there is a lack of population-level data on the interaction between OSA and glycemic control among patients with diabetes. We assessed the relationship between OSA severity and T2DM prevalence and control in a large multinational population.METHODS: We performed a cross-sectional analysis of 6,616 participants in the European Sleep Apnea Cohort (ESADA) study, using multivariate regression analysis to assess T2DM prev…
Baroreflex control of heart rate during sleep in severe obstructive sleep apnoea: effects of acute CPAP
2006
Baroreflex control of heart rate during sleep (baroreflex sensitivity; BRS) has been shown to be depressed in obstructive sleep apnoea (OSA), and improved after treatment with continuous positive airway pressure (CPAP). Whether CPAP also acutely affects BRS during sleep in uncomplicated severe OSA is still debatable. Blood pressure was monitored during nocturnal polysomnography in 18 patients at baseline and during first-time CPAP application. Spontaneous BRS was analysed by the sequence method, and estimated as the mean sequence slope. CPAP did not acutely affect mean blood pressure or heart rate but decreased cardiovascular variability during sleep. Mean BRS increased slightly during CPAP…
Spontaneous gastroesophageal reflux and airway patency during the night in adult asthmatics
2000
Controversies still exist on the role of nighttime gastroesophageal reflux (GER) in precipitating nocturnal asthma. We tested the relationship between GER and nocturnal bronchoconstriction by continuously and simultaneously monitoring both respiratory resistances and esophageal pH in seven asthmatics with moderate to severe GER disease. Twenty-nine GER episodes were found during the study night lasting more than 5 min (LGER) and 72 not longer than 5 min (SGER). Both long (LGER) and short (SGER) gastroesophageal refluxes were able to maintain significantly higher lower respiratory resistances (RLR) at the resolution of each GER episode (RLR(e)) with respect to baseline values. RLR, expressed…
Limbic activity in slow wave sleep in a healthy subject with alpha–delta sleep
2001
All-night electroencephalographic (EEG) activity was recorded in a healthy subject with known alpha-delta sleep. Recordings were made from all 19 of the 10/20 system electrode sites, and low resolution electromagnetic tomography (LORETA) was used to estimate intracerebral current densities. Sleep stages were compared within classical frequency bands by statistical parametric mapping (SPM). With the onset of sleep, occipital alpha abated. With increasing depth of sleep, alpha power increased in a region comprising the left frontal lobe, the anterior and parietal cingulum, and the anterior and medial right front lobe. In slow wave sleep (SWS), frontal alpha power was much greater than in wake…