Polysomnography

About: Polysomnography is a research topic. Over the lifetime, 19527 publications have been published within this topic receiving 858718 citations. The topic is also known as: PSG & polysomnogram.

Daytime predictors of sleep hypoventilation in Duchenne muscular dystrophy.

Abstract: Sleep hypoventilation is an inevitable consequence of Duchenne muscular dystrophy (DMD), usually preceding daytime respiratory failure. Appropriate scheduling of polysomnography and the introduction of noninvasive ventilation (NIV) during sleep are not defined. Our aim was to determine the parameters of daytime lung function associated with sleep hypoventilation in patients with DMD. As our method we chose a prospective comparison of wakeful respiratory function (spirometry, lung volumes, maximal mouth pressures, arterial blood gases) with outcomes of polysomnography. All measurements were made with subjects breathing air. Nineteen subjects were studied. The FEV(1) was correlated with Pa(CO(2)) (r = -0.70, p /= 2%); a Pa(CO(2)) of >/= 45 mm Hg was an equally sensitive (91%) but more specific (75%) indicator while a base excess of >/= 4 mmol/L was highly specific (100%) but less sensitive (55%). After introduction of NIV during sleep (n = 8), there was a significant reduction in wakeful Pa(CO(2)) (54 +/- 7.4 to 49.1 +/- 4 mm Hg, p /= 45 mm Hg, particularly if the base excess is >/= 4 mmol/L; (3) the decrease in wakeful Pa(CO(2)) after NIV administered during sleep implicates sleep hypoventilation in the pathogenesis of respiratory failure; and (4) impaired ventilatory drive is a possible mechanism for respiratory failure, as the NIV-associated decrease in wakeful Pa(CO(2)) occurs despite a further decline in ventilatory capacity, suggesting continuing deterioration in respiratory muscle function.

Value of the multiple sleep latency test (MSLT) for the diagnosis of narcolepsy.

Abstract: Since its introduction, the multiple sleep latency test (MSLT) has played a major role in the diagnosis of narcolepsy. We assessed its diagnostic value in a series of 2,083 subjects of whom 170 (8.2%) were diagnosed with narcolepsy. The sensitivity of the combination of two or more sleep onset rapid eye movement (REM) periods (SOREMPs) with a mean sleep latency of < 5 minutes on an initial MSLT was 70% with a specificity of 97%, but 30% of all subjects with this combination of findings did not have narcolepsy. In some narcoleptics who had more than one MSLT, the proportion of naps with SOREMPs varied substantially from the initial MSLT to the follow-up test. The highest specificity (99.2%) and positive predictive value (PPV) (87%) for MSLT findings was obtained with the criteria of three or more SOREMPs combined with a mean sleep latency of < 5 minutes, but the sensitivity of this combination was only 46%. The combination of a SOREMP with a sleep latency < 10 minutes on polysomnography yielded a specificity (98.9%) and PPV (73%) almost equal to those obtained from combinations of MSLT findings, but the sensitivity was much lower. Our results suggest that the MSLT cannot be used in isolation to confirm or exclude narcolepsy, is indicated only in selected patients with excessive daytime sleepiness, and is most valuable when interpreted in conjunction with clinical findings.

Predictive value of clinical features for the obstructive sleep apnoea syndrome

Abstract: The advantage of being a National Referral Centre for patients with suspected obstructive sleep apnoea (OSA) was used to seek clinical factors predictive of OSA, and thus determine if the number of polysomnography tests required could be reduced. Patients were mainly primary referrals, from an island population of 3.5 million. Two hundred and fifty consecutive patients underwent clinical assessment, full polysomnography, and a detailed self-administered questionnaire. This represents one of the largest European studies, so far, utilizing full polysomnography. Fifty four percent (n = 134) had polysomnographic evidence of OSA (apnoea/hypopnoea index (AHI) > or = 15 events.h-1 sleep). Patients with OSA were more likely to be male, and had a significantly greater prevalence of habitual snoring, sleeping supine, wakening with heartburn, and dozing whilst driving. Alcohol intake, age and body mass index (BMI) were significant independent correlates of AHI. After controlling for BMI and age, waist circumference correlated more closely with AHI than neck circumference among males, while the opposite was true among females. No single factor was usefully predictive of obstructive sleep apnoea. However, combining clinical features and oximetry data, where appropriate, approximately one third of patients could be confidently designated as having obstructive sleep apnoea or not. The remaining two thirds of patients would still require more detailed sleep studies, such as full polysomnography, to reach a confident diagnosis.

Sleep Disorders Medicine: Basic Science, Technical Considerations, and Clinical Aspects

Abstract: Part I Basic aspects of sleep: an overview of sleep neurophysiology of sleep biochemical pharmacology of sleep physiological changes during sleep. Part 2 Technical considerations: polysomnographic technique EEG, EMG and EOG EKG recognition of cardiac arrhythmias respiration and respiratory function - technique of recording and evaluation measurement of sleepiness/alertness - MSLT ambulatory cassette polysomnography sleep scoring technique techniques for the evaluation of sleep-related erections. Part 3 Clinical aspects: an approach to a patient with sleep complaints classification of sleep disorders sleep apnea syndromes insomnia narcolepsy motor functions and dysfunctions of sleep sleep, breathing, and neurological disorders sleep disorders in psychiatric illness sleep and other medical disorders circadian rhythm disorders parasomnias sleep disorders in the elderly sleep disorders in childhood sleep and epilepsy positive airway pressure in the treatment of sleep related breathing disorders.

The meaning of good sleep: a longitudinal study of polysomnography and subjective sleep quality.

Abstract: The present study sought to investigate the meaning of subjectively good sleep, using a longitudinal and intraindividual design. Eight subjects slept in an isolation unit according to an irregular schedule of 6 h sleeps and 1 h naps, designed to give normal amounts of time in bed (1/3 of total), but variable sleep quality. Eight sleeps and eight naps were used for longitudinal simple and multiple regression analyses with standard polysomnographical sleep variables as predictors and subjective sleep quality as dependent variables. The results showed that subjective sleep quality (and related variables) was closely related to sleep efficiency, but not sleep stages. At least 87% efficiency was required for ratings of 'rather good' sleep. In addition, sleep quality ratings improved with closeness (of the awakening) to the circadian acrophase (17.00-21.00 hours) of the rectal temperature rhythm. The subjective ease of awakening differed from most other other variables in that it was related to low sleep efficiency. Objective and subjective homologues of sleep length and sleep latency showed high mean intraindividual correlations (r = 0.55 and 0.64, respectively). It was concluded that objective measures of sleep continuity were closely reflected in perceived sleep quality and that sleep quality essentially means sleep continuity.