You are a sleep lab technician and are sorting through the records obtained the previous night. You found that at 1:20 a. m. EEG tracings showed low amplitude, high-frequency activity, and subject had very low muscle tone. Which of the following is likely?

a. The subject was easily awakened and did not report dreaming.

b. She was difficult to awaken and did not report dreaming.

c. Once she was awake she reported dreaming.

d. She was already awake at 1:20am.

EEG tracings showed low amplitude, high-frequency activity, and subject had very low muscle tone. (c) Once she was awake she reported dreaming.

Explanation:

The patient was in the REM sleep stage which is characterized by highly active brain with loss of muscle tone - Most of the dreaming occurs at this stage

The EEG shows a low-voltage, mixed-frequency pattern with sawtooth waves. The chin EMG tone is markedly diminished, and the EOG shows rapid eye movements.

Polysomnography is a technique which is used to study the sleep cycles and stages using continuous recordings of brain waves (EEGs), electrical activity of muscles, eye movement (electro-oculogram), respiratory rate, blood pressure, blood oxygen saturation, heart rhythm and, sometimes, direct observation of the person during sleep using a video camera.

The term polysomnography was first used to denote all-night diagnostic sleep studies in the year 1974