11 - Ambulatory Cassette Polysomnography

Abstract

Publisher Summary This chapter provides an overview of the ambulatory cassette polysomnography (PSG) technique. A multichannel cassette recorder suitable for PSG became available in 1971, and the first report of successful ambulatory PSG came 2 years later. Since then, the growth and acceptance of ambulatory PSG have progressed as techniques, indications, and limitations have been clarified. Ambulatory PSG implies freedom of movement for the patient. Ambulatory cassette PSG complements other standard laboratory assessments of sleep apnea, primary hypersomnias, and insomnia. In disorders of excessive daytime sleepiness, its primary utility is in diagnosis of suspected severe sleep apnea, follow-up assessment after intervention for sleep apnea, or preliminary overnight PSG before multiple sleep latency test. Ambulatory PSG may be used as the primary tool for evaluating insomnia. Its advantages include patient comfort and convenience, potential cost savings, ease of sleep stage scoring with the auditory transformation of the EEG, and simplicity of data handling and storage. Success in achieving interpretable studies hinges on the diligence of the technician. Liabilities of the ambulatory PSG are the absence of a technician to make technical corrections and behavioral observations and the limited number of channels.