Polysomnography

doi:10.1016/B978-0-444-64032-1.00025-4

Handbook of Clinical Neurology

Volume 160, 2019, Pages 381-392

https://doi.org/10.1016/B978-0-444-64032-1.00025-4 Get rights and content

Abstract

Polysomnography refers to a systematic process used to collect physiologic parameters during sleep. A polysomnogram (PSG) is a procedure that utilizes electroencephalogram, electro-oculogram, electromyogram, electrocardiogram, and pulse oximetry, as well as airflow and respiratory effort, to evaluate for underlying causes of sleep disturbances. PSG is considered to be the gold standard for diagnosing sleep-related breathing disorders, which include obstructive sleep apnea (OSA), central sleep apnea, and sleep-related hypoventilation/hypoxia. PSG can also be utilized to evaluate for other sleep disorders, including nocturnal seizures, narcolepsy, periodic limb movement disorder, and rapid eye movement sleep behavior disorder. With recent technological developments, home sleep apnea testing can be done to confirm a diagnosis in patients with a high risk for moderate to severe OSA in the absence of comorbid medical conditions or other suspected sleep disorders.

Section snippets

Polysomnography

The roots of the modern-day polysomnogram (PSG) are credited to the work of Caton (1875), who discovered brain wave activity in animals in 1875. This very early finding led to the description of differences between wakefulness and sleep by Berger (1929), and ultimately contributed to the first continuous overnight EEG recording during sleep (Loomis et al., 1937). Further work by Aserinsky, Kleitman, Dement, and Jouvet in the 1950s established the utility of the combined use of

Overview

A routine PSG requires a comprehensive monitoring system to record sleep stages, limb movements, airflow, respiratory effort, heart rate and rhythm, oxygen saturation, and body position. This type of study, also known as a Type I (Level I) sleep study, is done in a sleep lab with a trained sleep technician present throughout the duration of the study. PSGs are primarily used to diagnose sleep-related breathing disorders (SRBDs), including OSA, central sleep apnea, and sleep-related

Carbon dioxide

While not required, many in-lab PSGs include evaluation of carbon dioxide levels to assess for hypoventilation during sleep. End tidal CO₂ (EtCO₂) is measured using a nasal cannula that detects the end of breath CO₂ level during expiration. Alternatively, transcutaneous CO₂ (TcpCO₂) can be determined by using electrodes on the skin that measure CO₂ as a product of respiration. TcpCO₂ is frequently used in infants and children to avoid artifact and loss of signal that occurs more commonly with

Baseline PSG

A typical baseline PSG, also called a Type I (Level I) sleep study, includes the required measurements for EEG, EOG, chin and limb EMG, airflow signals, respiratory effort signals, oxygen saturation, ECG, and body position, to assess for SRBD and other signs of sleep disruptions, such as arousals or PLMs. Optional measurements include EtCO₂ or TcpCO₂, full EEG, or additional arm EMG leads.

PAP titration study

A PAP titration study is performed to evaluate effectiveness of various PAP therapies and pressure settings

Method for Reviewing and Interpreting PSGs

Interpretation of the sleep study includes review of the EEG, EOG, and EMG to stage each 30-s epoch of the entire recording. Arousals are also designated when present. The entire study is reviewed again in 2-min epochs to score respiratory events and limb movements. Body position is reviewed using video confirmation or body sensor devices. ECG is reviewed and any abnormalities are described. The sleep hypnogram is a diagram that is used to show an overview of the entire study (Fig. 25.2). A

Sleep architecture abnormalities

In-lab PSGs can identify abnormalities in sleep architecture. Sleep latency, calculated as time from start of study to sleep onset, is normally several minutes to 30 min in length. A very short sleep latency during a sleep study may suggest sleep deprivation. A prolonged sleep latency might suggest first-night effect (difficulty sleeping in a new environment) or insomnia (Ong et al., 2017). Additionally, a very high sleep efficiency, as calculated by total sleep time over total recording time,

Overview

Home sleep apnea testing (HSAT) is an alternative to PSG in the diagnosis of OSA. When used in accordance with the most recent clinical guidelines, HSAT can be part of the assessment and treatment of OSA (Collop et al., 2007; Kapur et al., 2017).

The HSAT is used only for the assessment of OSA in uncomplicated patients who are at moderate to high risk of OSA and who do not have comorbid medical conditions or other suspected sleep disorders (Table 25.1). HSAT is also not recommended in patients

Summary

PSG is considered to be the gold standard for the diagnosis of SRBD. Additionally, it can be used to evaluate a number of other sleep disorders, as well as to determine effectiveness of SRBD treatments. There are standardized methods and techniques for staging and scoring PSGs, which are included in the AASM scoring manual. Accredited sleep labs are required to follow AASM guidelines. HSAT can be utilized to confirm a diagnosis of OSA in patients who are considered to be at high risk for

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Chapter 25 - Polysomnography

Abstract

Section snippets

Polysomnography

Overview

Carbon dioxide

Baseline PSG

PAP titration study

Method for Reviewing and Interpreting PSGs

Sleep architecture abnormalities

Overview

Summary

Chest

Lancet

Electroencephalogr Clin Neurophysiol

Brain Res

Prog Brain Res

Chest

Sleep Med Clin

Lancet

Diagnostic value of video-EEG polysomnography

Neurology

Regularly occurring periods of eye motility and concomitant phenomena during sleep

Science

Uber das elektroenkelphalogramm des Menshcen [About electroencephalogram of Menshcen]

Arch Psychiatr Nervenkr

Auto-adjusting positive airway pressure treatment for sleep apnea diagnosed by home sleep testing

J Clin Sleep Med

For the American Academy of Sleep Medicine

Chronic hypoventilation syndromes and sleep-related hypoventilation

J Thorac Dis

Excessive sleepiness

Clini Stud Edinb

Normal human sleep: an overview

The electric current of the brain

Br Med J

Case of narcolepsy

Clin Soc Trans

Physician decision making and clinical outcomes with laboratory polysomnography or limited-channel sleep studies for obstructive sleep apnea: a randomized trial

Ann Intern Med

Clinical guidelines for the use of unattended portable monitors in the diagnosis of obstructive sleep apnea in adult patients

J Clin Sleep Med

Obstructive sleep apnea devices for out-of-center (OOC) testing: technology evaluation

J Clin Sleep Med

The promise of sleep

The posthumous papers of the pickwickian club

Home diagnosis of sleep apnea: a systematic review of the literature. An evidence review cosponsored by the American Academy of Sleep Medicine, The American College of Chest Physicians, and the American Thoracic Society

Chest

Video recordings and video polysomnogram