Polysomnography

This chapter outlines the basics of polysomnography as used in daily practice. It addresses the clinical application of polysomnography (PSG), its merits and limitations, and aims to provide insight in the 'art' of PSG interpretation and reporting. The chapter outlines the American Academy of Sleep Medicine (AASM) criteria to score the various respiratory events. In the AASM manual, several different PSG-based movement patterns are described, either as isolated phenomena, a specific syndrome or a combination of both. Sleep scoring is based on splitting the recording into 30-second epochs. Each epoch is scored as a particular sleep stage, taking into account additional rules for sleep stage transitions, as well as age-specific characteristics. Electrocardiographic recording is included in the AASM recommended parameters of PSG but only a limited derivation is required as standard, to exclude certain arrhythmias. The recording of sounds during PSG is a very important tool potentially serving multiple purposes.