The onset of depth electrodes allowed the targeting and monitoring of deeper structures of the brain such as the Hippocampus and Amygdala, and was initially used in conjunction with surface monitoring. Over the years this has developed into the practice of Stereo Electroencephalogram (sEEG), where only depth electrodes are placed, and the contact spacing is such that contacts are present in the deep and superficial structures of interest. The sEEG placement of depth electrodes tends to have less complications as a craniotomy is not required.
Ad-Tech have three ranges of depth electrodes available: Spencer Depth Electrode, Reduced Diameter 
Depth Electrodes (specialised for sEEG), and Macro-Micro Depth Electrodes (measures individual neuron activity). All depth electrodes come with platinum contacts and 19cm depth indication mark and stylet, however contact, number, size and space does vary.
To target all of the deep brain structures successfully, Ad-Tech have placement kits that work with most stereotactic, neuronavigation and robotic equipment, whether the electrode is being placed through a bolt or a burr hole.
Contact your local Severn representative to discuss further variations and placement options by following this link.
