Polysomnographs of different types for sleep disorders diagnostics

Polysomnography is a "gold standard" of sleep disorders diagnosis.

The International Classification of Sleep Disorders (ICSD) describes the different types of sleep disorders, such as obstructive or central sleep apnea syndrome, snoring, Cheyne-Stokes respiration, restless legs syndrome (RLS), bruxism, insomnia, hypersomnolence, parasomnias, and more than 90 types of other sleep disorders (www.sleepnet.ru).

Chronic sleep disorders can cause:

  • cardiac pathologies, such as arterial hypertension, arrhythmia, congestive heart failure (CHF);
  • metabolic changes, hormonal regulation, and, as a result, obesity, diabetes, and other diseases;
  • neurological and psychosomatic disorders, such as epilepsy, chronic cerebrovascular insufficiency, dysregulation of excitation and inhibition, depression, anxiety.

AASM classification defines different types of polysomnographs:

  • Systems recording a small number of parameters (Type III) with function of data recording onto a memory card in autonomous mode. Type III systems have a limited number of channels (from 4 to 15) and are used primarily for advanced respiratory (sleep apnea screening) and cardiorespiratory monitoring in a hospital, health and sleep research centers, or at home.
  • Mobile polysomnographic system (Type II) differ from Type III systems in number of channel (from 18 to 24) and include up to 6 EEG channels for sleep stages analysis and hypnogram building. The study can be performed in autonomous mode without a technician.
  • Stationary polysomnographic systems (Type I) include 24 and more channels. A characteristic feature of Type I systems is an increased number of EEG channels to diagnose sleep disorders related to epilepsy and other neurological diseases. System can include extra channels for ECG, EMG, motor activity, and other parameters (GSR, PPG, temperature, wetness, etc.).