bipolar derivation
An EEG montage configuration where each channel represents the voltage difference between two adjacent electrodes, enhancing localization of electrical activity.
Full Definition
Bipolar derivation is a fundamental EEG montage arrangement where each recording channel displays the potential difference between two spatially adjacent electrodes, rather than comparing each electrode to a common reference. This configuration creates a series of linked electrode pairs that form chains across the scalp, such as longitudinal bipolar (anterior-posterior) or transverse bipolar (left-right) montages. Bipolar derivations are particularly valuable for localizing epileptiform activity because abnormal electrical sources create characteristic phase reversals at the point of maximum activity. The technique enhances spatial resolution and helps distinguish between focal and generalized abnormalities. Understanding bipolar montage patterns is essential for accurate EEG interpretation and artifact recognition.
Usage
Usage note: Use lowercase unless at beginning of sentence; distinguish from referential recording
In Context
- "The spike showed clear phase reversal in the bipolar derivation, confirming a right temporal focus." — EEG interpretation report
- "Longitudinal bipolar derivation was employed to better localize the epileptiform activity." — Technical methodology note