What three variables are essential in EEG interpretation?

In EEG interpretation, frequency, morphology, and distribution are fundamental variables that provide critical insights into brain activity.

Frequency refers to the rate at which brain waves oscillate, measured in Hertz (Hz). Different brain states exhibit distinct frequency patterns; for example, alpha waves (8-12 Hz) are prominent during relaxed wakefulness, while delta waves (0.5-4 Hz) are associated with deep sleep. Understanding the frequency helps clinicians assess brain function and identify abnormalities.

Morphology describes the shape and characteristics of the EEG waveforms. Analyzing the morphology enables the identification of specific patterns that may indicate various neurological conditions, such as seizures or brain lesions. The shapes of the waves—whether they are sharp, slow, or rhythmic—carry significant diagnostic information.

Distribution refers to where the brain waves are located on the scalp, reflecting the spatial characteristics of brain activity. It is essential to recognize which areas are exhibiting specific types of activity, as localized abnormalities can suggest cortical lesions, focal seizures, or other disorders.

Together, these three variables allow for a comprehensive assessment of the electrical activity in the brain, aiding in the diagnosis and understanding of various neurological conditions.