High density EEG (hdEEG) is used in the diagnosis or evaluation of epilepsy and records the electrical activity in the brain.
An EEG records ongoing electrical activity generated by the neurons in the brain, which is why it is also called a “brain wave” test. Abnormal EEG signals have eplileptiform spikes and slow waves in the brain that are common in epilepsy even if the child does not show physical signs of having a seizure.
High density EEG monitoring is similar to EEG monitoring and uses a cap with a large number of scalp electrodes. In high density EEG, 128 or 256 electrodes are placed compared to 26 to 28 with regular EEG monitoring.
The average brain monitoring time with hdEEG is approximately one to two hours.