depth electrode
Surgically implanted intracranial electrode that records directly from deep brain structures.
Full Definition
A depth electrode is a thin, flexible electrode surgically inserted into deep brain structures to record electrical activity directly from areas not accessible to surface EEG electrodes. These electrodes consist of multiple recording contacts spaced along their length, allowing sampling from different depths within a single trajectory. Depth electrodes are primarily used in presurgical epilepsy evaluation to identify seizure onset zones in deep structures like the hippocampus, amygdala, or insula. They provide superior signal quality and spatial resolution compared to scalp recordings, but require neurosurgical implantation and carry associated risks.
Usage
Usage note: Hyphenated; distinguish from subdural grids and strips which record from cortical surface.
In Context
- "Depth electrodes placed in bilateral hippocampi revealed left-sided seizure onset." — Invasive EEG report
- "The depth electrode recording showed high-frequency oscillations at seizure onset." — Electrophysiology study