Delta Rhythm

**Definition:** Brain waves seen on EEG characterized by a high amplitude and a frequency of 4 Hz and below. They are considered the deep sleep waves observed during sleep in dreamless states, infancy, and in some brain disorders.

**Tree numbers:** - E01.370.376.300.150.875 - E01.370.405.245.287.875 - G07.265.087.875 - G11.561.127.875