Polygraphic Techniques

Abstract

Polygraphy is a method of electrophysiological investigation that allows the simultaneous recording and acquisition of several bioelectrical and non-electrical parameters correlating them with cerebral electrical activity. Polygraphy has therefore become the indispensable tool for the assessment of patients who need a differential diagnosis for a sleep disorder, movement disorder, and epilepsy.

The laboratory where polygraphy is carried out requires specific features: patient preparation room, recording room, control room, and room dedicated to data processing and storage.

The biological parameters that can be recorded with polygraphy can be observed directly as bioelectrical signals, brain activity, eye movements, muscle activity, cardiac activity, and sympathetic skin response, or in other physical forms non-electrical in nature, breathing, noise, identification of body position, pulse oximetry, and plethysmogram.

There are several products on the market that allow patients to be monitored at home via portable recording devices, some of which include video monitoring, and the American Sleep Disorders Association (ASDA) has established a four-level standard of practice guideline for the diagnosis of sleep-disordered breathing.